Marine Mammals in the News

Welcome to the student-authored online publication of news stories summarizing the latest and greatest scientific discoveries in marine mammal science.  Each year, University of Maine students in INT308: Ecology and Conservation of Marine Mammals select a peer-reviewed scientific journal article that has been published within the last year and summarize the findings of this article in a news story format intended for the general public.  This final assignment follows a semester-long series of discussions and critiques of paired news stories and scientific journal articles.  We hope by sharing our student-authored news stories online to improve public visibility and understanding of diverse topics within marine mammal science.

2018

How Much Longer Can An Ice Giant Live Without Ice? - By Tommy Augusto

Walrus’ genus name “odobenus” translates to “tooth walking” because walruses use their tusks to pull themselves up onto a platform from being in the water. Walruses can grow up to 11 feet, and weigh up to 4,000 pounds. There are about 200,000 walruses in the Pacific ocean, about 18,000 in the Atlantic and 5,000  in the Laptev sea. The walrus is able to dominate the arctic ecosystems as they can withstand below freezing temperature due to their thick layers of blubber. Walruses were almost pushed to extinction between the 18th and 20th century, because they were being hunted by the people in the North for food, hides, ivory and bones. Once people began to notice that the walrus population was depleting rapidly, conservationist stepped in and laws were created to restrict walrus hunting. Now, only certain indigenous people are allowed to hunt walruses. The population of walruses were able to grow back, and are now only listed as vulnerable as they have a stable population growth. Just when walruses could catch a break, they are now experiencing a new danger that is threatening to wipe them completely: climate change.

Walruses dominate the cryosphere, which is the frozen water or the floating glacials, and this zone is heavily affected by the slightest climate changes. Walruses use this zone to give birth, feed and nursing, but their water is beginning to warm and melt some of those floating glaicals. The walruses have been able to adapt through climate changes and decided to find new platforms as a herd, as their usual platforms are now thin and melting. This caused them to deplete a lot of energy to search for a new platform, but they are able to move their habitat range in order to adapt to the change. Walruses have shown to be capable of great adaptability, and success, almost more than all marine organisms. An example of this is back in 1980’s, walrus had about 30 haul out spots scattered around Bering Sea, but overtime, their number of haul out spots has been reduced to 22, but their population was unaffected. It is still unknown if this is a natural adaptation or if this is hinting towards great danger in the future for them.

Walruses are observed to be ditching their ice platforms, as there is starting to be less food for them there, and moving to some coastal areas, without ice, to haul out. Walruses that choose to haul out on land, tend to be very very far from their food source, and have to travel back and forth, depleting more energy than usual, as they used to just drift on ice. This now threats female and young walruses as they have to travel very far each day, which poses various threats to their population. Polar bears are beginning to do the same, as they moved to coastal areas for food which overlaps with walruses food source range, and this poses great danger to walruses population. When a Polar bear spooks a herd of walruses, the entire herd would stampede towards the water to avoid predation, but in the process they are trampling over young walruses and usually killing them, which is causing the population to once again deplete.

There has been many legislation signed off to protect walrus population, such as the Polar Code, which basically restricts anthropogenic interactions with them, basically allowing walruses to live without any other disturbances in order to help their population grow back. Walruses have been able to adapt every year to climate change and find new answers to new issues that arise, but it is unknown how long they can push their population to survive while climate change is exponentially getting worse.

For more information, check out the original scientific paper:

Tsiouvalas, A. (2018), Walrus: The sensitive giant in the era of climate change: Climatic adaptation and challenges. Working and Living Environmental Protection, 15: 63-72.

What Makes Algoa Bay Prime Real Estate for Indo-Pacific Bottlenose Dolphins? - By Jacob Breen

For most dolphins, life out in the open ocean comprises of hunting with your peers, whether that means a small close-knit group, or a mob of strangers.  Dolphins, in general, retain smaller groups in shallow, protected areas, where predation stress is low, and form larger groups out in pelagic waters to increase predator vigilance and their effectiveness during hunts.  However, this is not the case for one population of Indo-Pacific bottlenose dolphins residing off the eastern coast of South Africa.  Algoa Bay is characterized as the largest and eastern-most bay of the south coast of South Africa.  It is shallow and has a maximum depth of 70 meters.  The largest average and maximum group size ever reported of bottlenose dolphins were found in Algoa Bay, with 60 and 600 respectively.  One thing that’s interesting is that this population stays stable over the course of seasons, but why?

Nearby at the Wild Coast, again we see the opposite of what we would expect; a smaller bottlenose dolphin population at an open pelagic site.  This area has a large amount of fish within it, including sardines.  Although we must take into account the amount of predators that would be concentrated in this area, we still would expect to see a lot there, however it is significantly less than Algoa Bay with only 33 on average and a 250 max group size, so what makes Algoa Bay so special?  Well researchers are still having a hard time figuring that out.

Group size for dolphins is largely influenced by food availability, predation pressure, or a combination of the two.  Taking this into account and the fact that the population generally stays stable over time, we have to conclude that area has enough food to sustain that large of a group.  Even with the added protection of the larger group, shark attacks still occur.  Perhaps the animals in this bay have found an abundant and easily obtainable source of food that researchers have yet to identify. Or perhaps there is another reason entirely.  All that we know for sure at this point, is that more research needs to be done to find the root of the cause

For more information, check out the original scientific paper:

Bouveroux, T. N., Caputo, M., Froneman, P. W., & Plön, S. (2018). Largest reported groups for the Indo-Pacific bottlenose dolphin (Tursiops aduncus) found in Algoa Bay, South Africa: Trends and potential drivers. Marine Mammal Science,34(3), 645-665. doi:10.1111/mms.12471

Melon-Headed Whales and Their Correlation to Diet and Depths - By Bayley Bryant

Off the coasts of Hawaii are two populations of melon-headed whales. Of these two populations, scientists have little previously known knowledge regarding the content of their diet and diving behavior until now. The nature of the Hawaiian and Kohala melon-headed whale populations has tapped into scientist’s curiosity to unveil more about this particular species. As such, it is recognized that further examinations of these species would be considered valuable pertaining to the further understandance of their foraging behavior.

Furthermore, stomach analysis was determined by eleven stranded whales from the Hawaiian islands, with ten recorded between 2009-2017, and one from 1985. Practices involved when interpreting prey content in the eleven stranded melon-headed whales were as follows: bones of the prey items were fixed in formalin once removed, followed by a freezing procedure for future use. They later were thawed and rinsed by sieves, preserving the bones in 70% ethanol. Remaining samples were stored in alcohol at the Marine Mammal Laboratory in Seattle Washington. To determine prey size and mass, regression equations were used. In regards to the dive behavior analysis, data was collected by depth transmitting satellite tags deployed between the years of 2011 and 2014. Photographic matches to known individuals of the two populations were used to affirm population identity. Likewise, tags were deployed during three recorded encounters with the species.

In this study by West et al, through the Marine Mammal Science journal, Peponocephala electra’s diet was studied. In this case study, the prey of the Hawaiian melon-headed whales consisted of fifty one identified species that collectively represented groups of fish and cephalopods. Examples of such fish and cephalopods include Myctophid lanternfish and Enoploteuthid squid. Although cephalopod concentrations in diet outweighed fish concentrations in diet, the fish were what was found to be qualitatively dominant. Thus, evidence suggests that these whales forage for fish rather than cephalopods (squid, octopus, nautilus) as a preferred prey item.

Contrastingly, the diving behavior data between the three tagged whales was however sufficient and similar. While two of the whales represented are from the Kohal resident population (different from the Hawaiian population), the similarity between diving behavior of the two populations suggests that the use of the water column in the slope and offshore habitats resemble each other respectively. However, while the Kohal resident population inhabit shallower depths of waters, the Hawaiian Island individuals do not. This data is supported by tag locations of these mammals, as melon-headed residents of the Kohal population are found closer inland than that of Hawaiian melon-headed residents.

In conclusion, due to the similarities between the two distinct populations concerning dive behavior with the exception that the Kohal population dive at depths shallower than the Hawaiian population, it is imperative that stomach content of the Kohala resident population is assessed and analyzed to compare to that of the Hawaiian population. Thus, further knowledge regarding the diet of this specific population will provide a means of distinct or equivalent data from that of the Kohal population. In like manner, while it was found that melon-headed whales prefer foraging activity at night as opposed to day, it is a clear indicator that the surface layer and middle layer of the open ocean are critical foraging grounds.

For more information, check out the original scientific paper:

West, K. L., Walker, W. A., Baird, R. W., Webster, D. L., & Schorr, G. S. (2018). Stomach contents and diel diving behavior of melon-headed whales (Peponocephala electra) in Hawaiian waters. Marine Mammal Science, 34(4), 1082-1096. doi:10.1111/mms.12507

Commotion of the Ocean: Eavesdropping on the Harbor Porpoises of the Baltic Sea - By Sarah Burton

What would you do if you were able to eavesdrop on the elaborate conversations throughout the ocean? What stories would you be able to piece together by just listening? Ida Carlen et al. set out to cue into the dialogue of the ocean with hopes of hearing the story of the Baltic Sea harbor porpoises.

Harbor porpoises, Phocoena phocoena, are located throughout the world but the individuals inhabiting the Baltic Sea are of particular interest. These porpoises are the only cetacean found in the region and are unfortunately considered critically endangered. These mammals are highly susceptible to fishing bycatch, noise pollution and other human induced activities. These small dolphin-like creatures continuously produce sound via echolocation, when communicating or hunting. The ocean commotion this species causes can provide crucial insight to their population status. Past studies reveal that two distinct populations of harbor porpoises have been found to inhabit the Baltic Sea. The Belt Sea population is currently still monitored and is managed under a previously established management border, which protects their breeding grounds and winter migration. The second population, the Baltic Proper population, is more elusive and their current status is unknown and believed to be critical. Due to this ambiguity on the Baltic Proper porpoises, eavesdropping on their habitat is essential if scientists have any hopes in recovering and monitoring their population.

The researchers deployed 304 C-PODS all throughout the Baltic Sea, which are passive acoustic devices that are capable of listening and recording the porpoise clicks from their echolocation. Over the course of two years, the team collected enough data to suggest that both the Belt Sea and Baltic Proper populations still inhabit the sea, but with no overlap in habitat location. During the breeding months, the Belt Sea population can be heard clicking away in the Southwest region while the Baltic Proper porpoises established breeding grounds along the offshore Baltic Proper region. The Baltic Proper porpoise reproductive habitat is not managed or within a protected area and therefore is at high risk of bycatch, increased ocean noise via shipping traffic and other ocean pollutants.

The researchers suggests that with their newly collected data, new protected areas can be implemented around the Baltic Proper breeding grounds. Fisheries can also be evaluated to replace the harmful gillnets with alternative gears and reduce overall bycatch. The research can also be taken into consideration when looking at the production of underwater noise from heavy ship trafficked areas. Acoustic deterrents, monitors similar to C-PODS that produced a ping irritating to the porpoises, can possibly prevent the porpoises from entering predominant shipping routes in the Baltic Sea.

Simply putting an ear to the waters of the Baltic Sea, allowed Ida Carlen et al. to reestablish a population of harbor porpoises, that would have potentially been pushed to extinction from human activity. With the Baltic Proper porpoise’s story piecing together, it’s easy to understand the importance of listening to our environment. Next time you’re near the ocean, listen and think, what’s the commotion of the ocean trying to say?

For more information, check out the original scientific paper:

Carlén, I., Thomas, L., Carlström, J., Amundin, M., Teilmann, J., Tregenza, N., . . . Acevedo-Gutiérrez, A. (2018). Basin-scale distribution of harbour porpoises in the Baltic Sea provides basis for effective conservation actions. Biological Conservation,226, 42-53. doi:10.1016/j.biocon.2018.06.031

The Stress of a Shark Attack-ack-ack-ack-ack: The Seals Oughtta Know by Now - By Kari Costopoulos

Imagine you’re swimming in the ocean. The water is cool and calm, the air is warm and the sun is shining. Everything seems blissful. That is, until a massive white shark lunges from beneath the waves to devour you. Sounds pretty stressful, right? Well, fortunately for you that’ll probably never happen. Why? Because one you’re not a seal, and two, you’re not living on Seal Island arguably the most stressful environment for Cape fur seals.

Neil Hammerschlag, a professor at the University of Miami, has conducted a multi-year study off the Western coast of South Africa. He tested the predation-stress hypothesis, using the various colonies of Cape fur seals and their interactions with the surrounding white sharks. The predation-stress hypothesis, is as interesting as it’s understudied. The researchers explained that, “it predicts that exposure to risk causes increased secretions of glucocorticoids”. This study is one of few, to observe stress responses of prey populations in low and high risk areas of their natural habitat. The importance of this study is needed in the modern world as we lose predator populations and we don’t fully understand how they interact and impact their prey.

From this study, the researchers were hoping to learn 4 things about predation/prey stress. They were to:

  1. See whether the different seal colonies displayed signs of spatial/seasonal variations of fecal-glucocorticoid metabolites (fGCM) in response to white shark attacks
  2. Test if fGCM was found in higher concentrations where shark abundance and attacks were more frequent
  3. Determine if features of a seal’s surroundings influenced the type, frequency, and magnitude of shark predation risk
  4. See if there was a difference in physiological stress between adults and juveniles by looking at fGCM in their scat

To accomplish a study of this grandeur, the researchers had to first understand the Cape fur seals of the areas. Researchers determined that white sharks actively target fur seals of certain colonies, and only during the winter. During these months, predation risk is high, and different colonies experience more risk than others. The seals found in False Bay, most notably Seal Island, experience the highest risk of all. On average, they experience ~1.97 attacks per hour which is estimated to be about 18 times greater than seals inhabiting a separate colony on Geyser Rock-which only experiences ~0.1 attacks per hour on average. Differing landscape features may be the cause of this as False Bay is exposed without any kelp beds or coral reefs, which causes unpredictable predation.

The study followed tagged white sharks and tracked their abundance specifically to False Bay, Mossel Bay, and Geyser Rock. At each, seal scat was examined to determine if levels of fGCM correlated with white shark abundance and attacks.

The results of the study found that elevated levels of fGCM were found in areas exposed to frequent and unpredictable attacks. It was also found the fGCM rates did not correlate with adults/juveniles or shark abundance.

For more information, check out the original scientific paper:

Hammerschlag, N., Meÿer, M., Seakamela, S. M., Kirkman, S., Fallows, C., & Creel, S. (2017). Physiological stress responses to natural variation in predation risk: evidence from white sharks and seals. Ecology, 98(12), 3199-3210.

Are Drones Scaring Away Our Blue Whales Instead of Aiding Research? - By Grace Cullinane

The invention of drones (unmanned, self propelled aircraft) has opened the door for innovation for a wide variety of applications in diverse career fields, but are they doing more harm than good? In wildlife management and research, drones are being used more often. The lower cost, maneuverability, and relatively low disturbance of the drones as compared to previously used sampling methods makes them highly desirable for research purposes.

Of course there is always a drawback. Drones produce noise, air disturbance, and to some species, may resemble predators, so understanding how drones may affect your target species is vital when planning to use them in research. If animals are easily disturbed by drone sampling, this can lead to unnecessary stress, and even biased data. Due to the novelty of drone sampling in most fields however, there is little viable data on how it affects most species. Which brings us to the blue whale.

So what do the whales think of this? Luckily, from the research performed by Carlos A. Domínguez‐Sánchez and his team, they don’t seem to mind. Blue whales are an elusive, long ranging species that little is known about. One way scientists can gain a lot of information from a single whale is blow sampling. This involves getting a sample of exhaled air and water from a surfacing whale which provides important health and demographic information such as hormonal levels and DNA. Drones provide a minimally invasive option for collecting this data. By flying behind a whale when it exhales, the drone can collect a sample and return it to researchers, who can operate the drone from a safe distance.

Domínguez‐Sánchez and his team observed whale behavior when approached by a drone performing a blow sample and compared it previous behavior observations and found there wasn’t any apparent difference in whale behavior. Previous observations not related to this study observed whales diving prematurely when drones approached from head on, which can affect their dive recovery and feeding behavior. The most important aspect of drone sampling they concluded, was to have a professional control the drone, and to follow the sampling protocol, which details how to approach the whale without spooking it. Of course, more studies will have to be performed for other species, but for now, we have the go ahead to use drones as a sampling tool, and hopefully we will gain a deeper understanding of these mysterious giants.

For more information, check out the original scientific paper:

Domínguez‐Sánchez, C. A., Acevedo‐Whitehouse, K. A. and Gendron, D. (2018), Effect of drone‐based blow sampling on blue whale (Balaenoptera musculus) behavior. Mar Mam Sci, 34: 841-850. doi:10.1111/mms.12482

Bottlenose dolphins self-recognize earlier than human children - By Dylan Cunningham

The ability to recognize oneself in a mirror is an ability we all take for granted. Most of us have been amused by a dog barking at itself in the mirror or a cat jumping in fright as it passes its own reflection. Mirror self-recognition (MSR) is a behavioral trait only shared by a handful of species, which include humans, dolphins, elephants, the great apes, and magpies. MSR is indicated by self-directed behavior when the animal in question is confronted with a mirror. (For example, the animal exhibits repetitive behaviors or body parts otherwise unobservable.) In humans, the emergence of MSR is generally between 1 ½ and 2 years of age, and in chimpanzees, it is roughly between 2 ½ and 3 ½ years of age. At the beginning of this year, two researchers at the National Aquarium in Baltimore, MD sought to perform a study that identified the onset age of MSR in bottlenose dolphins. They performed mirror tests on two young dolphins named Bayley and Foster. The tests were simple, performed for one hour twice a week and consisted of putting a mirror in the dolphin’s pool and taking video footage for analysis. They found that bottlenose dolphins develop MSR capabilities at about 7 months of age. This age is significantly earlier than all the other species reported to exhibit MSR, including humans. One might be tempted to say that this discovery means that dolphins are more intelligent than humans. However, this is not necessarily the case. Dolphins do not show signs of some of the higher consciousness qualities of humans, such as reading and analytical deduction, but they do seem to have faster social development in the early years of life.  This discovery is a valuable insight into the early cognitive development of dolphins and their awareness of self. It is also a valuable contribution to the general knowledge of mankind regarding the phenomenon of consciousness, and how and why it develops in some species, including our own.

For more information, check out the original scientific paper:

Morrison R, Reiss D (2018) Precocious development of self-awareness in dolphins. PLoS ONE 13(1): e0189813. https://doi.org/10.1371/journal.pone.0189813

Solar Flare? Or Solar Impair? - By Alex Flynn

For decades sperm whales have been documented stranding all over the world. Many theories have emerged such as following food source and wandering off course, or changes in tide. But their true underlying causes and mechanisms still remain unclear. In a study published in the International Journal of Astrobiology, scientists conducted a study on a series of a total of 29 male bachelor sperm whales (Physeter macrocephalus) that occurred in the North Sea in early 2016. The astrobiologists (Vanselow, K., Jacobsen, S., Hall, C., & Garthe, S.) (2018)  believe that the mass strandings are actually due to geomagnetic storms on the surface of our sun.

Geomagnetic storms are temporary disturbances in Earth’s magnetosphere that is caused by large disruptions on the surface of the sun. This can range from solar flares to coronal holes in the sun and solar mass ejections. Large geomagnetic storms even have the possibility of causing major blackouts through the disruption of power grids. These geomagnetic storms typically occur 20 to 30 days post disruption on the sun’s surface.

How is it possible that a fiery storm millions and millions of miles away cause this you may ask? It is believed that sperm whales magnetic sense plays an important role in orientation, especially during migration. And as many of these sperm whales are younger and lack experience migrating to higher latitudes (where magnetic disruptions are stronger), it is very possible that they will become disoriented on the way during a geomagnetic storm.

Through close observations of storms that occurred in early to mid 2016, the scientists found that in higher latitudes, the magnetic field lines (in particular the North Sea) have a greater the vertical component. Cochran et al. (2004) reported that the vertical component is incredibly important for birds in order to calibrate their magnetic orientation with the setting sun once a day. Once again it is believed that this behavior applies to whales and if so it would explain the mass strandings of juvenile males who have never ventured into the North Sea.

It is important to note that 22 of the 29 whales that were stranded had autopsies performed on them and there were no visible causes of death. The stomach’s contained mostly marine biological waste and there was no indication that any of these whales were sick.

All in all, it is important to try to understand all theories and supported ideas on how we are losing not only sperm whales but other species of marine mammals as well, whether it is due to stranding or other. Solar storms do seem to have a correlation with whale stranding in northern latitudes, specifically the North Sea. However more evidence is needed to confirm this theory.

For more information, check out the original scientific paper:

Vanselow, K., Jacobsen, S., Hall, C., & Garthe, S. (2018). Solar storms may trigger sperm whale strandings: Explanation approaches for multiple strandings in the North Sea in 2016. International Journal of Astrobiology, 17(4), 336-344. doi:10.1017/S147355041700026X

Are you ready for some SEALOUS facts about Leopard Seals? - By Matthew Fornaciari

Leopard Seals are considered an apex predator which means they are extremely important to the environment. An apex predator is a predator at the top of the food chain that has no other predators. They “feed on fish, other seals penguins and krill”. Their main diet consists of krill. This species have not been studied too much because they are hard to track because of the cold environment and the rough waters they thrive in. Just like every other type of seals, the leopard seals perform the action of a haul out. A haul out is when seals get out of the water to spend time on land or ice in this case.

The time that Leopard seals spend out of water has been closely observed and studied by Lain J. Staniland. He ran tests and studied the movements of leopard seals year round and what affects this type of activity. Leopard Seal “movements between and behaviour within areas important to breeding populations of birds and other seals shows that they are vital in the management of the southern oceans resources” (Staniland).  If leopard seals were to go extinct, it would cause a huge issue in the southern ocean ecosystem. The Seals that were tracked and examined when they were migrating to South Georgia and Bird Island showed that their haul out period was “between 22 and 31% of their time.’ ‘The maximum time spent in water was between 13 and 25 days’ (Staniland) before they hauled out of the water. There are many factors that play a role in the haul out time for leopard seals. During the summer time the haul out period was longer and happened more often than the winter because of the temperature difference between the air and the water.

Leopard Seals also migrate from Antarctic waters to sub Antarctic Islands. They do this for food mainly and also because of the temperature of the waters. They were found to migrate to Bird Island and South Georgia which is an island that has shallow shelf waters in which the leopard seals were perceived to like because they are shallow water hunters. The haul out behavior when the seals are spotted around this area is that, they will haul out mainly on open ice because they prefer colder environments and it will be more frequent than when spotted in warmer areas.

Leopard Seals are an interesting species and there is much more to learn about them. Hopefully in years to come we will be more knowledgeable on the species and get a better idea about the way they act in different environments and how they can adapt to stressful/different areas.

For more information, check out the original scientific paper:

Staniland IJ, Ratcliffe N, Trathan PN, Forcada J (2018) Long term movements and activity patterns of an Antarctic marine apex predator: The leopard seal. PLoS ONE 13(6): e0197767. https://doi.org/10.1371/journal.pone.0197767

Do “Pessimistic” Dolphins Stress More? - By Garrett Gadow

Dolphins are smart, like seriously smart. The trouble is that they don’t speak english and, so it can be really hard to understand just what a dolphin is really feeling. In a study published in March 2018 by Isabella Klegg and Fabienne Delfour from the University of Paris, scientists devised an experiment to help understand how bottlenose dolphins think and how each has a unique disposition.

The scientists involved in the study focused on a particular set of actions called anticipatory behaviors. These behaviors are performed by dolphins when they are predicting an upcoming event. The study focused on two actions, spy-hopping and surface-looking, both actions involve the dolphin lifting their head above water and focusing their eyes on a trainer or object. From a human perspective these actions may seem to convey excitement, but the study looked deeper to try and understand what the actions can tell us about the stress levels and moods of the dolphins performing them.

The experiment involved 8 dolphins living in aquarium environment. The scientists set up in view of the pool while the behavior of each dolphin was recorded. The dolphins were then asked to swim away, touch a float and return to one of five stations across the pool. The dolphins were shown that the trainer on one end of the pool had a herring (tasty!), while the trainer one the opposite end only gave a short applause, but the rewards from the three trainers in between were left ambiguous. Each dolphin repeated the test with the trainers calling them back to a different one of the five stations each time. The amount of time that it took the dolphins to return to each trainer was recorded.

Unsurprisingly the dolphins returned most quickly to the trainer they knew would give them a herring and most slowly to the trainer they knew would only give applause. The surprising results came from the three ambiguous stations in between. The faster a dolphin returned to the trainer the more optimistic the dolphin was thought to be about getting a fishy treat. Dolphins which returned more slowly were thought to be pessimistic about their chances of receiving a treat. The return times for each dolphin were compared to the number of anticipatory actions exhibited before the experiment and an interesting result emerged.

Dolphins which performed more anticipatory behaviors, also had a more pessimistic disposition, meaning they returned more slowly to the trainers when they weren’t sure if they would get a treat or not. The scientists who ran this experiment think that, this may be correlated to stress levels, because a dolphin which places too much importance on receiving a reward may be lacking stimulus in other areas. Although we are still miles from truly knowing what a dolphin is thinking, the experiment has helped shed light on how we can interpret their behaviors and provide them with a better lifestyle.

For more information, check out the original scientific paper:

Clegg, Isabella L. K., and Fabienne Delfour. “Cognitive Judgement Bias Is Associated with Frequency of Anticipatory Behavior in Bottlenose Dolphins.” Zoo Biology 37.2 (2018): 67-73.

Movement limitations of the northern elephant seal on land: we know it can dive, but can it run? - By Emily Gagne

If you have visited the coast, you may have had the opportunity to see seals basking on the beach. These types of animals spend a lot of their time on land, which may be surprising considering their special features that make them efficient swimmers. Their blubber and flippers certainly help them navigate the ocean, though they still come up on land to mate and give birth to their pups. During this time, seals may flop and bounce across the beach at a slow pace, indicating that all of their special features for swimming come with a trade-off: they greatly limit terrestrial locomotion.

Kelsey Tennett and her team from West Chester University in Pennsylvania researched the “flopping and bouncing” movement of seals to characterize their terrestrial movements. The primary species of focus was the northern elephant seal, the second largest seal in the world. To understand their movement, the research team video recorded wild male northern elephant seals at Año Nuevo State Park in California in January of 2015 and 2016. During this period, seals were on the sandy beaches to breed. A total of 70 males were recorded as they moved freely throughout the beach. They measured the distance they traveled so they could calculate the seals’ speeds. Additionally, the video footage was used to closely assess just how the seals flopped and bounced.

Unlike terrestrial mammals, the researchers found that the northern elephant seals rippled their bodies and moved in a wave-like pattern, which they dubbed “spinal undulations.” Starting at the hind flippers, the seals lifted back portions of their bodies and shifted their weight until the neck extended out and the whole body was shifted forward. In other words, if you were to lay down on the ground face-down and only did the worm to move forward, you would be undulating like a northern elephant seal on land.

Tennett and her team found that undulations increased with velocity, which varied between about 1 and 5.5 miles per hour. Foreflippers and the pelvic region were used as support, though foreflipper movement did not increase with increasing undulations. In other words, no matter how fast times their spines moved, their foreflippers did not try to keep up with a “running” motion across the sand. Lastly, researchers compared the effort needed travel across the beach, and found that the mechanical power for the northern elephant seal was greater with increasing size.

There is no doubt that terrestrial environments are still very beneficial to seals to mate and breed, though their bodies adapted for swimming certainly don’t aid their locomotion on land. We can imagine just how exhausting it would be to exclusively do the worm all the time, so the next time we see seals basking out in the sun on the beach, let’s be sure to let them get their well-deserved rest.

For more information, check out the original scientific paper:

Tennet, K.A., Costa, D.P., Nicastro, A.J., Fish, F.E. (2018). Terrestrial locomotion of the northern elephant seal (Mirounga angustirostris): limitation of large aquatically adapted seals on land? Journal of Experimental Biology. 18-0117.

Is Broome, Australia not Good Enough for Mother Whales? Scientists Look into Reports of Expanded Calving Grounds - By Mykayla Hagaman

Off the west coast of Australia near Broome, tourists are well used to seeing a mother humpback whale and her calf. However, recent sightings much further south have led scientists to question just how far the calving grounds extend along these beachy shores. Intrigued by the number of sightings, Lyn Irving, a PhD student at the University of Tasmania, set out to conduct surveys to better understand just how far south humpback whales give birth.

Little is known about the specific range of humpback calving grounds, but usually females give birth to their calves within 30 degrees of the equator. During the summer months, humpback whales can be found near Antarctica, feeding on krill and waiting to begin their migration north. They begin this journey in the fall where many whales swim up the western coast of Australia. These whales belong to a subpopulation know as Breeding Stock D, which is the largest population of humpback whales in the world. The females will give birth to their calves in these warm, shallow waters where they are safer from predation by killer whales.

In order to track where the whales are giving birth, Irving and her team flew aerial surveys over the North West Cape of Australia, the location of southern calf sightings. Irving was on the lookout for neonatal humpback whales, or whales that are less than 4 weeks old, traveling north. This direction of travel would indicate that the calf had been born further south than where first spotted. Flights were conducted during 2013 and 2015. Overall, 105 calves were identified during the two-year study, of which 85 percent in 2013 and 94 percent in 2015 were neonates. Based off of minimum predicted calf population sizes, 20 percent of all calves of the Breeding Stock D population were expected to be born as far south as the North West Cape. This newly discovered calving ground is an extension of 1,000 km to the southwest of the currently known calving ground.

This recently unknown area is situated in an area of high human activity which could cause some future problems for the mothers and calves. As calves are entirely dependent on their moms and highly vulnerable to predation, protecting calving grounds is an important step to protecting the future generations of humpback whales. How calving grounds are impacted by humans will greatly influence the future size and stability of whale populations as a whole. For these reasons, it is very important for scientists to have a better understanding of the full extent of the calving range in order to better form policies that can protect and assist in the recovery of this majestic species.

For more information, check out the original scientific paper:

Irvine, L., Thums, M., Hanson, C.E., McMahon, C.R., and Hindell, M.A. (2017). Evidence for a widely expanded humpback whale calving range along the western Australian coast. Marine Mammal Science 34(2) 294-310

Slow Boats Protect our Gentle Grazers of the Sea - By Alissa Johnson

The Florida manatee is the only manatee species in the US, and is one of the most endangered aquatic species. Today, there are roughly 6,000 manatees in Florida, and around 85% of all identified manatees have been reported to have scars from boat collisions. Boat strikes are one of the leading causes for manatee deaths in Florida. Even a boat travelling at 13-15 mph can be fatal. The Florida manatee is very important to the marine environment and to humans as well. They eat an immense amount of seagrass in the coastal waters keeping the seagrass short and healthy. This makes the manatees a keystone species, which is the name given to species that play a critical role in their ecosystems. Without the manatees, the seagrass would become overgrown, causing the habitat to collapse and making it difficult for boats to pass through.

Scientists from Florida State University and Florida Fish and Wildlife came together to conduct an experiment on how the behavior of manatees changes in relation to boats to learn about how the species can be preserved. In their journal Manatee Behavioral Response to Boats, manatee behavior during boat approaches was examined to get a better understanding as to why boat collisions occur. It was conducted by tagging 18 manatees in the northern portion of Charlotte Harbor National Estuary over the course of  2 years. The manatees were released with two different tags. One of them, called a digital acoustic tag (DTAG) recorded their sounds, different types of movements, temperature, and the acoustic environment. The second tag is a GPS tag which tracks the manatees’ movements, and boat traffic was mapped in the area. Data was collected in multiple locations in Charlotte Harbor. The first year, data was recorded in Lemon Bay, and in Placida Harbor and Gasparilla Sound the second year. Data was recorded in non winter months because this is when boat traffic is at its highest. The manatees were observed by boat for several hours 2-4 days after the manatee has been tagged. All tags on the manatees were removed within a few weeks of the manatees being tagged.

Over the course of this study, a total of 346 boat passes were recorded. 72.5% of these boat passes were more than 50m from manatee(s), 19.1% were in between 50m-10m, and 8.4% were within 10m of manatee(s). The distance between manatees and boats had a significant effect on the manatee’s behavior. The most common changes were swimming speed, water depth, and scanning the environment. The boat encounters that were less than 10m away are the most relevant to boat strikes. In these close encounters, 89% of manatees changed their behavior.  The closer the boat, the more likely the manatees would change their behavior. One important finding was that manatees respond quicker to boats that are travelling slowly compared to boats that are travelling faster. This suggests that boat speed restriction zones are an essential management tool for reducing manatee injury and death due to boat strikes.

For more information, check out the original scientific paper:

Rycyk, A. M., Deutsch, C. J., Barlas, M. E., Hardy, S. K., Frisch, K., Leone, E. H., & Nowacek, D. P. (2018). Manatee behavioral response to boats. Marine Mammal Science, 34(4), 924-962. doi:10.1111/mms.12491

The touchy-feely life of a sea otter - By Hannah Kerrigan

The sea otter is known for its cute and cuddly appearance, and it’s touchy feelyness. Who can’t smile at a picture of them holding paws or rubbing their faces? Other than being adorable, otters rely on their paws and whiskers (referred to as vibrissae) for a much more important use.

Sea otters can consume a wide variety of prey including crabs, mollusks and even fish, however most show a favorite and specialize in the capture of a specific prey item. Because their hunting grounds are often deep, dark, and cloudy they rely on touch to find their foods. Specifically, they rely on their very sensitive paws and whiskers to distinguish their prey in the soft substrate. Their impressive dexterity also allows them to perform the classic surface behavior of cracking mollusks and crabs with the use of a rock.

In a study done by Strobel et al., they looked at how sea otters performed underwater, and how long it took them to make decisions. A 4-year-old sea otter was trained for 17 months, using positive reinforcement to use just paws or just whiskers in both air and water. In place of prey she was trained to recognize grooved acrylic plates, getting a shrimp every time she touched a 2mm grooved plate. They tested her ability to tell the 2mm grooved plate from various other grooved plates ranging from 2.1mm to 5mm. A correct determination (choosing the 2mm plate) got her the reward of a large shrimp.

The same human experiment was done on land, although they didn’t get a shrimp for a correct answer. Four humans were blindfolded and asked to wear sound canceling headphones, then directed to determine which plate had smaller grooves using only their hands, again the 2mm grooved plate being the standard.

The results showed that this particular sea otter (and likely others) are slightly more accurate with their paws than whiskers and perform slightly better in air than water. But that wasn’t the surprising part, the surprising part was how she went about deciding what plate to choose. She always explored the right plate first then either selected that plate, or immediately chose the left plate and she only used her right paw. She remembered what the standard plate felt like and if the right plate didn’t feel similar enough, she immediately chose the left plate. This may however have caused her accuracy to drop, as the other plate got closer to the standard she tended to pick the one she touched first, which was always the plate to the right.

This showed a surprising likeness to the human experiment, in which the humans primarily used their dominant hand. Although the accuracy was about the same as a sea otter, the humans took considerably longer to make a decision. The average time for the sea otter was .2 seconds, the average for a human was 6 seconds. If the situation ever arose where humans needed to forage on the ocean floor, we would not outcompete these furry critters.

For more information, check out the original scientific paper:

Strobel, S. M., Sills, J. M., Tinker, M. T., & Reichmuth, C. J. (2018). Active touch in sea otters: in-air and underwater texture discrimination thresholds and behavioral strategies for paws and vibrissae. The Journal of Experimental Biology. https://doi.org/10.1242/jeb.181347

Dugongs? In Northwest Qatar? It’s More Likely than you Think - By Kai La Spina

Did you know that the country of Qatar in the Middle East has the largest dugong population outside of Australia? What if I told you that the largest dugong group ever reported was spotted between Qatar and Bahrain? Researchers (Christopher D. Marshall, Mehsin Al Ansi, Jennifer Dupont, Christopher Warren, Ismail Al Shaikh, and Joshua Cullen) at various universities including the University of Galveston and Qatar University have been studying the large number of dugongs that seem to use the Northwestern part of the country for feeding purposes. The dugong, also known as the sea-cow, is the only marine mammal that is a strict vegetarian. They are incredibly unique, but sadly vulnerable in our changing ocean. There’s not a lot known about aspects like their distribution, life history, and population biology in the Qatar region, which is undergoing large changes from things like coastal development, and oil/gas exploration. According to local populations, dugongs are in decline. These declines are likely because of aspects touched on above, but in addition, a high number of bycatch from fisheries in the region should be mentioned, too. Even though dugongs are protected nationally and internationally, bycatch is a tricky issue to fix because of how much the people of coastal regions like Qatar rely on seafood. So, why do these sea-cows like the Northwest part of the country so much? It’s probably to eat, of course! Although the region is hypersaline, meaning really salty, there are a few species of seagrass that grow healthily in the waters surrounding Qatar. In the large congregations of dugongs observed by the researchers, the most common activity was eating. The reason that these animals were spotted in the large groups they were in is not concluded to be definite by the researchers, but they believe it may have something to do with behavioral thermoregulation. Behavioral thermoregulation is the act of modifying your behavior to become warmer, like when you huddle in closer to a person/people if you are cold to gain heat. So, what can we make of all of this? The study by Marshall et al. is important because it shows that the northwest region of Qatar is an important habitat for dugong populations, which are decreasing in size with our changing oceans. Although coastal development and oil/gas exploration in this part of the country has not begun quite yet, it will pick up soon enough, meaning that there are important topics of discussion regarding the conservation of the animals that live there. The researchers of this study advocate for a Marine Protected Area (MPA) to be established for the safeguarding of the dugong populations that the local people have grown to appreciate for what they are: incredible sea-cows, unlike any other marine mammal species!

For more information, check out the original scientific paper:

Marshall, C. D., Ansi, M. A., Dupont, J., Warren, C., Shaikh, I. A., & Cullen, J. (2018). Large dugong (Dugong dugon) aggregations persist in coastal Qatar. Marine Mammal Science, 34(4), 1154-1163. doi:10.1111/mms.12497

Pinging Prevention: Are Pingers Enough to Prevent Harbor Porpoise Bycatch? - By Kyle Lima

Imagine swimming through coastal waters in search of food when all of a sudden you happen upon a school of your favorite dining cuisine. Next thing you know, you’re caught in a net and dragged onto a boat without any warning. According to Lotte Kindt-Larsen and her research team, this phenomenon, known as bycatch, is one of the most impactful factors threatening a small toothed whale called the Harbor Porpoise.

Today, development of various technologies have started to combat this issue of bycatch by fishing vessels. A type of acoustic alarm system called pingers are the most common device used to provide a warning signal to marine mammals. This warning signal is meant to deter them from approaching the nets used by fishing vessels. These devices are placed directly on the nets, and have been shown to reduce bycatch rates in some studies. Although these devices have been mandated in many areas, it isn’t clear the range at which they can be heard, or if they are having any detrimental effects on these animals.

Over the span of 5 years from 2010 to 2015, Kindt-Larsen and her research team conducted studies on two common types of pingers. They were able to compare an older model (AQUAmark100), to a newer, updated model (AQUAmark300). They found that the newer model could be heard for much further distances, which is crucial for these porpoises to be able to avoid nets.

So the new model can be heard from farther away seemingly helping the porpoises, but does it negatively impact them in any way? Well, it seems that in some cases it might, according to Kindt-Larsen. Their study, as well as others, showed that these pingers can actually cause porpoises to abandon the area completely, although this also is dependent upon the oceanic noise pollution. In addition to displacement, some porpoises may actually get used to the alarm and begin to ignore it. This was the case with the newer model of pinger, but interestingly, they did not see habituation with the older model.

What is the best choice then? It is clear that pingers in general have various costs and benefits, but at the current time, better technologies have yet to be invented. So for now, we may have to settle with an imperfect deterrent while we work to implement and develop better ways to prevent bycatch. This way we can lessen the detrimental effects of bycatch, while still allowing hard working people to make a living through fishing.

For more information, check out the original scientific paper:

Kindt-Larsen, L., Berg, C. W., Northridge, S. and Larsen, F. (2018). Harbor porpoise (Phocoena phocoena) reactions to pingers. Mar Mam Sci, 00(00): 1-22. DOI: 10.1111/mms.12552

Which Are More Like Their Ancestors, Seals or Sea Lions? - By Cailian Liu

As we all know, marine mammals evolved from land mammals, but now they are very different in both morphology and behaviour. Can you imagine that seals and sea lions are close relatives with bears? It’s true. Mammals today may differ greatly, but in actuality share similar ancestors. So how do you determine whether seals or sea lions are more like their ancestors? David P. Hocking et al.(2018) has done a series of investigations to examine the anatomy and behaviour, that discovered that seals can eat like their ancient ancestors due to clawed forelimbs.

In anatomy, David P. Hocking and his team compared the forelimb structure of seals, sea lions and fossil seals. They found that true seals have flexible digits and strong claws, which is similar to terrestrial carnivores, while an sea lion’s forelimb digits are integrated to form a stiff, wing-like flipper. This phenomenon suggests true seals tend to be more like their ancestor since all marine mammals evolved from terrestrial mammals. In addition, the bone of true seal’s knuckle is trochleated (functions like a pulley), which is similar to that of Enaliarctos, which are the ancestors of pinnipeds, and also that of terrestrial carnivores, while the sea lions’ are flattened.

In behaviour, David P. Hocking and his team observed 123 wild seal’s feeding events in Scotland and 20 seal’s captive feeding trials at the Alaska SeaLife Center. They found that wild northern true seals routinely use their primitive forelimbs to assist with processing large prey, which is called’ Hold and tear’ processing. As for sea lions, they preferred to use ‘shaking’ behaviour to process large prey, which is similar to other aquatic mammals like bottlenose dolphins. However, modern terrestrial and semi-aquatic carnivores also use their forelimbs to secure prey while it’s processed using the teeth. This suggests that true seals retain the feeding behaviour of ancestors during the transition from land to sea.

A more interesting fact is that true seals are often considered to be more aquatically adapted than sea lions because of the hind limb for aquatic locomotion and the ability to dive deeper. Therefore, I can confidently say that the seals are one kind of amazing animals that retain the anatomy and behaviour of their terrestrial ancestors and are well adapted to the aquatic environment at the same time. What’s even more fascinating is that these features of seals are adapted to the first stage of transition from feeding on land to feeding completely underwater, providing us the understanding of how species cross the boundary between terrestrial and aquatic existence in behaviour and anatomy.

For more information, check out the original scientific paper:

Hocking DP, Marx FG, Sattler R, Harris RN, Pollock TI, Sorrell KJ, Fitzgerald EMG, McCurry MR, Evans AR. (2018) Clawed forelimbs allow northern seals to eat like their ancient ancestors. R. Soc. Open Sci. 5: 172393. Available at http://dx.doi.org/10.1098/rsos.172393

Boats vs Manatees, Titanic 2.0? - By McKenna Martin

The speed you drive your boat around manatees may actually be a case of life or death for these creatures.  Manatees are a vulnerable species with populations decreasing constantly.

One study by Athena Rycyk et al., done in the southwest region in Florida, found that boats affect important manatee behavior.  The behaviors affected are heading, rolling, fluking, and depth changes.  Eighteen manatees were captured, tagged with a GPS and DTAGs, released back into the waters, and were ready to be followed!

With the four behaviors being observed, a baseline for normal behaviors was defined.  The heading behavior is when a manatee sticks its head out of the water.  Fluking is a behavior that was rated as low, intermediate, or high depending on how many strokes the manatee displayed.  Depth change is how deep a manatee dove with a boat present compared to how deep they would normally dive.  Rolling is a behavior in which a manatee will roll sideways and do a complete circle.

Boat collisions are very common in this area and have been a leading factor in mortality within this population of manatees.

This study found that when looking at a whole, the speed of a boat doesn’t have a significant difference of behavioral changes in manatees.  However, slow driving boats did allow for manatees to have more time to respond to an approaching boat and the behavioral reactions did occur faster with the slow speeds.  When multiple boats were present, the speed did not really matter because all of the noises confused the manatees and caused more behavioral changes.

Not only is boat speed an issue but also how close you go to the manatee.  Close proximity (within 10m) causes the worst effects in behaviors exhibited by these manatees and causes more damage than the speed at which the boat was going.  This information is interesting to know because, the way they conducted the study was by following the manatees by boat.

When using your boat on the water, make sure you’re cautious of the speed you are going and if you spot a manatee in its home, do not get to close!  If you want to see the manatee, turn your boat off and let them approach you since you’re the guest in their home.

For more information, check out the original scientific paper:

Rycyk, A., Deutsch, C., Barlas, M., Hardy, S., Frisch, K., Leone, E., Nowacek, D. (2018). Manatee behavioral response to boats. Marine Mammal Science

Dolphin Brain Development: Why are Their Brains so Big? - By Grace McDermott

At 29 weeks old, a human fetus can hear sounds coming from outside its mothers body. At this age, the part of the baby’s brain responsible for processing sound is only half way formed. Now imagine if this part of the brain was fully developed at only a few weeks old into pregnancy. What would the brain look like?

The answer to this question lies within the findings of a recent study on dolphin brain development. The study focused on forty-two different dolphin species and nine species of baleen whales, noting the factors that contributed to increased brain size in each species. The study found that a baby dolphin is born with a brain already half the size of its fully formed adult brain. For reference, our babies are born with only 20-30% of the adult human brain volume. While we have our fastest period of brain growth during the first three years of life, dolphins experience this rapid brain growth period while still in the womb. The study also found that dolphin fetal brain development is related to how long the mother’s gestational period is. So, you might wonder whether this means that if we also had 18 month long pregnancies like killer whale moms, maybe our newborn’s brains would double in size.

However, we have to take into account that dolphins live a very different lifestyle from the typical human. Dolphins use echolocation as a form of sight and communication. They use it to hunt for prey, talk to each other, and find mates. Developing echolocation requires a lot of brain power. Nonetheless, it’s been argued that echolocation doesn’t require a large brain as bats use echolocation but lack brain size. It’s difficult to compare the echolocation of a dolphin to a bat’s though, because a dolphin’s prey is almost the same density as the water surrounding it. To combat this, dolphins use fast pace high frequency clicking while hunting which requires rapid information processing. The development of echolocation is believed to attribute to a dolphin’s advanced auditory system resulting in a larger brain size and accelerated fetal brain development.

But don’t larger animals have larger brains? Although a dolphin mother’s body size was proven to be correlated to their baby’s brain size, the brain sizes of terrestrial mammals of similar body size were still significantly smaller. One major difference between dolphins and their terrestrial counterparts is diet. While the land mammals of similar body size such as elephants and cows typically consumed an all vegetarian diet, the dolphins are carnivorous feeding on high energy foods like fish. This energy is consumed by the mother which then enters the baby through the umbilical cord, facilitating brain growth

Studies like this one help supply knowledge so we can better understand how life works. This new information has opened many doors for future studies on mammal brains and can even be applied when examining our own.

For more information, check out the original scientific paper:

Ridgeway, S. H., Carlin, K. P., & Van Alstyne, K. R. (2018). Delphinid Brain Development from Neonate to Adulthood with Comparisons to other Cetaceans and Artiodactyls. Marine Mammal Science, 34(2), 420-439. DOI: 10.1111/mms.12464.

Humpback Whales Have Something Caught in Their Trap - By Liz Piotrowski

Imagine sitting in one place with your mouth open as food is catered directly to you. For the humpback whales (Megaptera novaengliae) off northeastern Vancouver Island, this is novel foraging strategy defined as “trap-feeding.” In the study, The innovation and diffusion of “trap- feeding,” a novel humpback whale foraging strategy, McMillan et al. (2018) provide the first statement of this foraging innovation and examine the ecological and social variables that align with its diffusion through use of sighting data and video analysis.

As changes occur within the environment, organisms learn to adapt through a variety of ways that can be dependent on their behavior and physiology. For instance, the foraging behavior of an individual may change when there is a shift in prey abundance, distribution or availability. Humpbacks have been commonly observed to use a variety of foraging techniques, such as “lunge-feeding.” In this case, an individual, at the surface, will swiftly swim toward their prey with their mouth open and will then proceed to take in a gulp of their prey and surrounding water. Humpback whales have bilaterally separate jaws and expandable throat pleats that enables them to engulf a vast amount of water while allowing them to obtain a large portion of their prey.

Although humpbacks off northeastern Vancouver Island have commonly used lunge-feeding as a technique to feed on juvenile Pacific herring, two individuals were first reported to also trap- feed in 2011 (McMillan et al., 2018). Since then, more than fifty-five humpbacks have been documented to trap-feed in this area today (McMillan et al., 2018). This novel foraging technique has been defined when a humpback-whale floats just below the surface with its mouth for an extended period of time (at least 4 seconds). Millan et al. (2018) described that this usually involves the whale turning in a single place or using its long pectoral flippers to force/flick prey into its mouth. Additionally, one may compare the nature of trap-feeding to that of a Venus fly trap.

Overall, McMillan et al. (2018) suggest that this novel foraging strategy may be an energy and cost-efficient technique used in situations where smaller and more diffuse herring schools are present. In other words, the lack of acceleration prior to opening its mouth when trap-feeding may accommodate for the energy-loss when feeding on lower density schools of herring. Interestingly enough, this study was also able to observe a symbiotic relationship between these humpback whales and the seabirds present during trap-feeding sessions. More specifically, the methods of seabirds feeding below and above the surface water create a dynamic that better forms/sculpts herring into denser schools, therefore allowing the humpbacks to more efficiently feed (McMillan et al. (2018). In addition, this foraging technique was observed across multiple offspring whose mother had never been recorded to trap-feed, further indicating that this strategy most likely diffused culturally amongst other individuals within the same population.

Ultimately, observing and documenting such behavior may allow us to further current knowledge and improve monitoring systems regarding ecosystem health. Marine mammals are apex predators that are important indicators of ecosystem health. Could trap-feeding foraging strategies be implying a change in the ecosystem that is causing more small and diffuse schools of herring to occur? Furthermore, it is necessary that additional research may be conducted, such as genetic analysis, to provide further awareness into the diffusion of this novel behavior.

For more information, check out the original scientific paper:

McMillan, C. J., Towers, J. R. and Hildering, J. (2018), The innovation and diffusion of “trap- feeding,” a novel humpback whale foraging strategy. Mar Mam Sci. . doi:10.1111/mms.12557

Using native know-how—how traditional ecological knowledge can influence Beluga health monitoring - By Danielle Plumlee

Here’s a question for you—how well do you think that you would be able to live off of the land if the necessity ever arose? I mean, sure, you can manipulate that smart phone in your pocket with ease, but how about reading the land for signs of potential food and water, or finding safe places to set up a camp? Or setting up a camp?

My point is, the modern luxuries of life may have dampened those ancestral skills and instincts that kept the human species alive in the days of hunter-gathering. Native peoples, however, still rely on those skills for subsistence. This knowledge of the environment, that comes from years of observations and experiences with the land, passed down from one generation to the next, is invaluable to native peoples’ survival.

Researchers interested in Beluga health monitoring in waters north of Alaska and Western Canada were interested in tapping into this native know-how, or traditional ecological knowledge. This is no easy task, as it can be difficult to convince native peoples to share their knowledge. No surprise, as their concerns stem from fears of their knowledge being taken advantage of, or misconstrued in translation, as scientists attempt to quantify their livelihoods.

However, the researchers recognized the importance of integrating scientific knowledge with traditional ecological knowledge in order to co-monitor Beluga health in this region, an increasingly important task as the environment is beginning to see rampant changes with climate change.

Through a combination of public meetings, questionnaires, interviews, and focus group review, the researchers made efforts to record accurate information and fill any gaps in knowledge with the Western Canadian Inuit. The focus group of native peoples had to reach a 2/3 majority in order to determine if the described characteristic was enough to qualify as a recommended health monitoring measure—for example, sick whales were said to be slower and to surface more frequently to breathe, however it was said that sick whales could dive normally as well, so this did not become a recommended marker of Beluga health.

The researchers considered the suggested health indicators the Inuvialuit research participants conveyed, and made monitoring recommendations based on them. Whales were considered thin and likely starved when their backbone stuck out and they had thin blubber at the chest, with a lot of rolled skin. The backbone as an indicator of health would be monitored with the survey questions, body condition charts, and maximum girth measurements.

Native knowledge can have significant insights on the environment or a particular species. Documenting traditional ecological knowledge is up and coming in the scientific world, however it is important that researchers working with native peoples take the utmost measure to ensure respect and accuracy of the data that is being willingly shared with them—nothing would be worse than sharing your livelihood, how your people have existed for generations, only to have an outsider trample all over it or take advantage.

For more information, check out the original scientific paper:

Ostertag, S. K., Loseto, L. L., Snow, K., Lam, J., Hynes, K., & Gillman, D. V. (2018). “That’s how we know they’re healthy”: the inclusion of traditional ecological knowledge in beluga health monitoring in the Inuvialuit Settlement Region. ARCTIC SCIENCE, 4(3, SI), 292–320. https://doi.org/10.1139/as-2017-0050

Sea otters and their impressive sense of touch: how are they so good at hunting in the dark depths of the sea? - By Brea Salter

While sea otters are widely known as top predators and keystone species, studying their diets proves difficult because they often exhibit more shy behaviors when humans are present. In fact, they often will stop feeding and hunting altogether when humans are observing. So, how to study these elusive yet voracious predators?

Sarah Strobel of University of California Santa Cruz’s Long Marine Laboratory enlisted the help of a four-year-old female sea otter by the name of Selka to help answer how sea otters are so successful at hunting small invertebrates such as urchins and mussels at dark depths in the ocean in which vision is limited. The researchers hypothesized that since sea otters dive to hunt in these areas of limited light, they likely have other heightened senses to help them find food.

To study exactly how efficient sea otters are at touching the world around them to find food, Strobel and the other researchers experimented with a single sea otter first by teaching her to recognize a board with two millimeters grooves in it. They did so by utilizing classic positive reinforcement training over the course of seventeen months. Each time Selka interacted with the grooved board in a way that was helpful to the researchers, she was rewarded with food. Since the sensory systems in question were the otter’s paws and whiskers, Selka was rewarded with her favorite treat any time she touched the board with those body parts.

After seventeen months of becoming familiarized with the two-millimeter grooved board both in air and water, the true test of Selka’s ability began. In each test, she was led to a contraption which allowed either her only her paw or face (equipped with blindfold so that she could not see) to touch the objects, depending on whether her paw or whiskers sensitivity were being tested. She was prompted to select the board that she had been familiarized with for seventeen months over a board that had both wider and narrower grooves. When she selected the correct board, just as in the training exercise, she was rewarded with food.

The results? Sea otters are pretty darn good at detecting their environment using touch. Compared to humans tested in the same experiment, Selka was 30-fold faster with her paws than human hands. She was slightly slower when using whiskers compared to paws, but still impressively quick. Considering she and other sea otters dive in dark environments for such small animals to eat, this decisiveness is certainly an important ability.

For more information, check out the original scientific paper:

Strobel, S.M., Sills, J.M., Tinker, M.T, Reichmuth, C.J. (2018). Active touch in sea otters: in-air and underwater texture discrimination thresholds and behavioral strategies for paws and vibrissae.  Journal of Experimental Biology: 221.

The voices of Antillean manatees - By Samantha Silverbrand

In the world of marine mammology, vocalization in marine mammals is not a new phenomenon for scientists. However, the manatee is an up and coming study subject on the matter. Specifically, scientists Rebecca Umeed, Fernanda Loffler Niemeyer Attademo and Bruna Bezzera are looking into the vocal behaviors of the Antillean manatee in their most recent study, “The influence of age and sex on the vocal repertoire of the Antillean manatee (Trichechus manatus manatus) and their responses to call playback” (2018).

Vocal acoustics, or the production of sound by an animal, is often found to be the main form of communication among individuals in environments that are less suitable for other senses, such as a marine environment. Hearing in manatees is suggested to be their main sense, as sight and smell can often fail them in the muddy waters they inhabit. Previous research on the hearing range of manatees is unclear, categorizing their auditory range anywhere from very broad to very narrow ranges. These results make it difficult to characterize why manatee vocalizations are observed. Other research looks to mother-calf pair vocal recognition as a tie to why manatees vocalize, along with individual recognition and mating opportunities as is found in other marine mammals.

The basis of the study set out to fill in the gaps of manatee sounds that other studies haven’t filled. Researchers wanted to characterize the different vocal repertoires observed in adult and juvenile manatees of both genders, and to see if there is a response to vocal recordings replayed to them underwater. By the end of the study, the researchers had characterized 6 distinct vocal patterns observed in adult males (4), adult females (7) and juveniles (3 males, 1 female). Of those vocalizations, squeaks, screeches and trills were observed in all groups while some specific calls were associated by gender: whines were associated with adult males, creaks with adult females and rubbing with juveniles. Young manatees were found to have longer calls than adults, and females had lower frequency calls than males.

Data was also collected on the manatee responses to vocal pattern playback collected from some of the same individuals in the study. When these different vocalizations were replayed to them (squeaks, screeches and trills), visible physical responses and increase in vocalization from every individual was recorded. Responses were recorded from all manatees when every vocalization was played, and the silent control elicited no response.

From the data collected in the study, it is suggested that manatees have a wide range of hearing capabilities, as well as multiple vocalization types through their life stages and between genders. Data also supports the recognition of vocal signals from playback of recordings due to physical and vocal response in the animals, and thus vocal communication between individuals other than mother-calf contact. Further research is suggested to characterize what exactly these vocalizations are being used for.

For more information, check out the original scientific paper:

Umeed, R., Attademo, F. L. N., Bezerra, B. (2018) “The influence of age and sex on the vocal repertoire of the Antillean manatee (Trichechus manatus manatus) and their responses to call playback”. Marine Mammal Science, 34(3): 577-594.

New Assessment May Possibly Allow Researchers to Understand How Animals Feel - By Alyna Stober

Wish you could talk to animals and truly understand what they’re feeling?  From movies such as the Dr. Dolittle series and role models such as Disney Princesses, talking to animals has been a talent many of us wish to possess.

A need for this talent has increased as publicity of animal care facilities has increased, in both positive and negative ways.  Many people question the safety of the animals within captivity due to past negative occurrences.  This is caused by assumptions made about how these animals feel based on what we see.  However, not enough research has been done to look at the animal’s emotional state which is why Isabella Clegg and Fabienne Delfour created the Marine Mammal Welfare Assessment, an assessment which measures three components of the animal: behavior, physiology and cognition to determine the health of a captive marine mammal.

These three components of welfare are used to understand the overall emotional response of the marine mammal through the use of the Triangulation principle.  This principle places the three components of welfare as points on a triangle with the center being the animal’s true emotional response.

While many facilities already use enrichment programs and toys to enhance the captive surroundings some researchers believe it may not be enough and only creates short-lived happiness for the animal.  With so little known about how these animals truly feel, the welfare assessment seems to be the best approach.

This assessment was evaluated on captive Bottlenose Dolphins, as the first marine mammal tested.  The study measured each component (physiology, behavior and cognition) separately.

During the physiology assessment researchers measured cortisol (stress) levels, respiration rate and dive depth of the dolphins.

The behavior assessment consisted of testing for social stress and instability, close bonds, cooperative behavior and prosocial tactile behavior (grooming and playing) between individual dolphins within a group.

The cognition assessment was the most difficult test to measure for therefore the only measurement the researchers have found and tested for was whether the dolphin favored the left or right hemisphere of their brain.  This was done by seeing which side of their body adults placed their young when they sense danger.

All these measurements were compiled and together determined the emotional response of the dolphins which was deemed mostly positive.   It was viewed in the behavior assessment that some dolphins didn’t get along with other ones, so changes were made to accommodate each dolphins’ need.

Using this welfare assessment could help animal care facilities truly understand what their animals are feeling and change their procedure to better fit the animal, like a teacher explains a concept in different ways to accommodate for multiple viewpoints.

Welfare research is new and expanding.  By evaluating how these animals feel while in the wild and in captivity researchers can gain a new insight to these creatures that could never be considered before.  Instead of humans saying what these animals feel, they can tell us.

For more information, check out the original scientific paper:

Clegg, I. and Delfour, F. (2018). Can We Assess Marine Mammal Welfare in Captivity and in the wild? Considering the Example of Bottlenose Dolphins. Aquatic Mammals, 44(2), pp.181-  200.

Can you mana-see? - By Samantha Wagg

Manatees are marine mammals that may go unnoticed. Maybe you might know them better as the ‘sea cow’. The gentle giants, that can get to an impressive age of 60 years were once known as endangered, but are now listed as a threatened species. Under the protection of both the Endangered Species Act and the Marine Mammal Protection Act, the manatee’s numbers have steadily increased since the 1970s to somewhere over 6000 individuals. Now I know that they might not be as popular as your humpback whales or bottlenose dolphins, but they are still at risk of boat collisions, particularly off the southwest coast of Florida. In fact, it was found that 25% of manatee deaths resulted from reported boat collisions as well as 54% of adult manatee deaths where the cause of death was known.

Rycyk and colleges performed a study in the northern portion of the Charlotte Habour Estuary, an area with heavy boat traffic, to determine what manatees do in response to boats. A total of 18 manatees were studied with two already having fresh boat wounds. To measure their responses they fitted the manatees with some nifty tracking gear, DTAGs that record sounds, as well as recording aerial videos from above. This allowed them to track where the manatees were in the water, the sounds that they and the boats produced as well as seeing what their behaviours were.

Boats travelling off the southwest coast of Florida can hits speeds of more than 32 km/h. I know this may seem slow, but think of it this way, manatees usually travel at a speed of 8 km/h, which is four times slower than these zooming boats! Faster moving boats have been shown to pose a bigger threat to manatees than slower boats since they have less time to react.

During the study most boats didn’t approach the manatees closer than 50 m but, there were still boats passing them being within 10 m. They found that when boats passed within 10 m of the manatee that 89% of them had a behavioural change within 22.7 seconds. These behavioural changes included diving to deeper water, swimming faster, lifting their tails and heads out of the water and rolling. If a big, loud, scary boat was coming towards you, I’m pretty sure you would try move out of the way too.

So what is currently being done to ensure the safety of these slow, gentle creatures? Several management tools have been put in place in an effort to reduce mortality. Things like speed-restriction zones can reduce the severity of injury to these animals if they happen to be hit. Manatee sanctuaries can ensure they have safe areas to roam free. Also local plans and reviews of boat facilities can help to ensure boat traffic isn’t in highly populated areas. So these tools are useful strategies to reduce collisions of manatees, but how effective are they really? Will better rules and regulations need to be placed in the future in order to better protect this species?

For more information, check out the original scientific paper:

Rycyk, A.M., Deutsch, C.J., Barlas, M.E., Hardy, S.K., Frisch, K., Leone, E.N & Nowacek, D.P. (2018). Manatee behavioural responses to boats. Marine Mammal Science, 34(4): 924-962. doi: 10.1111/mms.12491

Can’t Touch This: High Tactile Sensibility of the Sea Otter - By Joshua White

I’m sure we’ve all been asked this, “would you rather lose your sense of sight or hearing?” Many of us might consider these to be the most important of the five basic senses that we have as humans. For the environment in which we inhabit those senses could very likely be our most important. But consider you live in a world where both vision and audibility are strongly inhibited, what then? Well for amphibious mammals, such as the sea otter, this is the type of world in which they live. When foraging on the sea floor for food, visualization of their surroundings is increasingly difficult compared to in air, and nearly impossible after the sun sets. While also lacking the adaptations for auditory communication and navigation like other marine dwelling mammals (such as dolphins), how is it that the sea otter can locate food so successfully? The answer lies in their paws and face, where the sea otters are very well-developed for tactility (sense of touch). But just how good is the sea otter’s tactile sensibility? How does it compare to humans, who also have an extremely well-developed sense of touch?

A recent paper, Active touch in sea otters: in-air and underwater texture discrimination thresholds and behavioral strategies for paws and vibrissae by Sarah McKay Strobel et al., explains a study that explored the discriminatory abilities of sea otter’s touch. This study used a single mature female otter that was trained to perform the tasks needed to undergo this investigation.

In this experiment, the otter needed to display its ability to discriminate between textures in both under-water and open-air environments, using either her paws or vibrissae (whiskers). To do this, the scientists created an apparatus that presented the otter with two different plates side by side. Each of these plates had grooves of different widths machined into them, and one of the two options was deemed the “correct” plate. The otter had been pre-exposed to the “correct” plate’s groove width during training. During experimentation the otter was always given the option between a correctly grooved plate and an incorrect one to choose between. While having only the sense of touch to rely on, the otter needed to correctly distinguish between the two and make a correct decision. Interestingly, in terms of numbers of correct answers, the sea otter had achieved sensibility of a similar level as human subjects who were put through comparative testing. However, the sea otter had response speeds that surpasses that of humans by a long shot, with her paws she was 30-fold faster than humans and 15-fold faster in her whiskers.

The results of this investigation lead us to begin understanding the adaptations that allow for sea otters to be the highly efficient top predators that they are. Such rapid and accurate tactility likely allows for incredibly effective foraging, that may otherwise be challenging if relying on other senses.

For more information, check out the original scientific paper:

Strobel, S.M., Sills, J.M., Tinker, M.T, Reichmuth, C.J. (2018). Active touch in sea otters: in-air and underwater texture discrimination thresholds and behavioral strategies for paws and vibrissae.  Journal of Experimental Biology: 221.

2017

A Woman’s Touch: Bringing ladies into upper scientific management - By Emily Borger

Picture a scientist. What type of person do you see? What do they look like? Chances are, if you are in the majority of the population, you pictured an elderly man such as Albert Einstein or Steven Hawkings.

The idea of the stereotypical scientist is so ingrained in our culture that it’s difficult to combat. However, for the past few decades, we have been trying to do just that. More and more women have been entering into scientific fields such as the marine sciences, to help increase gender diversity, but the representation is far from equal. The further you travel up the ranks, the less you can find women represented. This is called the ‘leaky pipeline.’

What causes the ‘leaky pipeline?’ According to Sascha Hooker in her article “Equity and career-life balance in marine mammal science?”, the cause can be a mix of different things: through both internal and external decisions. Statistically, women are more likely to focus on “work/life balance” than men, prioritizing family over career building. Scientific jobs, especially marine mammal focused studies, are incredibly time and labor intensive. Many marine mammal research jobs require frequent traveling for long periods of time. Dolphins and whales don’t care whether or not you have children at home; they travel out to sea whether it’s convenient for you or not.

Another possible cause for the lack of ladies in the upper scientific community could be because they simply haven’t had the time to climb the ranks. Until fairly recently, around the late 20th century, women were not allowed to work aboard research vessels or work in the Antarctic with the men. Even now, the deep-set bias towards men in science remains. All male faculties are more likely to hire men than women, while at the same time not accepting the evidence for gender-bias in science. As a result, it becomes increasingly difficult for women to gain ranks the higher they climb.

So how do we plug the leaky pipe? Hooker suggests a few possible strategies to help increase women representation in the sciences including: increased focus on mentorship, intentional gender equalization in hiring, and forming discrimination and harassment positions in the Society for Marine Mammalogy. In addition, she suggests encouraging women to pursue career advancement. While these solutions are a step in the right direction, much more work is required before the sciences can achieve true gender equity. Until then, the scientific community lacks a valuable perspective in many areas of research that can be provided through a woman’s touch.

For more information, check out the original scientific paper:

Hooker, S. K., Simmons, S. E., Stimpert, A. K. and McDonald, B. I. (2017), Equity and career-life balance in marine mammal science?. Mar Mam Sci, 33: 955–965. doi:10.1111/mms.12407

Marine Mammal Scientists are Now Using their Phones at Work - By Maya Caines

When looking at the environment we can use certain species as an indicator of possible health risks and issues that may end up being prevalent to humans. One species that is an indicator of environmental health are bottlenose dolphins (Tursiops truncatus). Scientists, Leslie Hart, Kerry Wischusen and Randall Wells are doing just that but in an unexpected manner.

Scientists look at something known as reference intervals (RIs) to set a base of what is considered healthy and normal for a specific species. But, how do you get detailed information quickly when working with such a large animal? The answer: an app. This method has been looked at as a new way to determine if an animal is combatting health issues due to environmental stressors in real time!

So how do scientists do health assessments on these dolphins which can be anywhere from 10-14 feet and upwards of 1,000 pounds? Dolphins are moved to shallow water where scientists are then able to draw blood as well as do a quick examination on the animal. Some individuals were lifted out of the water to be weighed, and measured, to collect samples. All this data was put into an app, “Cetacean Health”, which was developed by using an app inventing software created by MIT. The app was then able, after some calculations  to determine if the dolphins were under or overweight as well as other details about their health. Additionally, the app creates graphs that provide a visual component to any data collected. This allows scientist to determine where the dolphin falls on the health scale.

After the initial tests were done, the app was brought into the field to test how practical the use of an app actually was. And it worked! The overall consensus was that the app was a fast and easy way to get data processed quickly, which is important when looking at species that are susceptible to stress. This is something that scientists and veterinarians can bring onto the field to quickly asses the environmental impacts on the species. This could also lead to more apps that engage people in citizen science where everyday people can record what they see on any excursion they may go on and report data. Guess there is an app for everything.

For more information, check out the original scientific paper:

Hart, Leslie B., Kerry Wischusen, and Randall S. Wells. “Rapid Assessment of Bottlenose Dolphin (Tursiops truncatus) Body Condition: There’s an App for That.” Aquatic Mammals 43, no. 6 (2017): 635-44.

Marine mammal babysitting to help out the whole population - By Quinn Carey

In mammals parenting and watching over young is primarily done by the mother, but in some species other individuals lend a hand (Augusto et al. 2017). Alloparenting, or alloparental care, is the watching of young by another member of its species that is not the biological parent of that individual, and is similar to the human behavior of babysitting. This behavior is beneficial to the young as it provides increased protection, grooming, huddling, and food resources (Gubernick et al. 2000).

In the paper ‘Characterizing alloparental care in the pilot whale (Globicephala melas) population that summers off Cape Breton Nova Scotia’ lead scientists Joana Augusto, Timothy Frasier, and Hal Whitehead studied the relatively unknown parenting behavior of this species. Observations were made from a whale watching vessel that crossed through Pleasant Bay Harbor, this trek was repeated five times each day from 2009 to 2011.

Specifically Augusto and her team were attempting to determine the amount of time a calf and adult spent together to determine what they called “closest companions”. Alloparenting was characterized as the observation of two or more close companion encounters between a calf and an adult, who was not the mother. Identification of individuals was determined by photographing the whales fins or characteristic features.

By the end of the study the team had collected 661 encounters of pilot whales, 85.9% of which included calves. They were able to identify 356 calves, but only 92 were observed to have over two closest companionship encounters with individuals other than their mother. The findings also showed that over 50% of the calves were observed with more than one companion and were escorted by the pod as a whole.

From the data collected on the whale watches it was determined that alloparenting behavior was performed by whales unrelated to the calf, and each event was short lived. This was an unexpected outcome, because it was assumed that alloparenting would occur in closely related whale groups, as they are longer lasting and more tight knit (Augusto et al. 2017). The researchers also found that most of the babysitting was done by the males, stated to be a positive social experience for calves similar to bottlenose dolphin or sperm whale socializing (Whitehead et al. 1996). Finally, it was also determined that alloparental care can be altruistic to the adults monitoring the young, but benefit the species as a whole (Augusto et al. 2017). Because this is a behavior that does not directly benefit the whale performing it, Augusto stated that “ there is no evolutionary mechanism associated with the behavior, and alloparental care is a byproduct of this species’ social structure”.

Alloparenting was seen to be a common occurrence in the Cape Breton pilot whale population, a behavior likely to have a positive affect this species. Having numerous individuals watch over the young is important for pilot whales, as escorting and constant calf care reduces the risk of predation and increases the calves overall probability of survival.

For more information, check out the original scientific paper:

Augusto, J. F., Frasier, T. R. and Whitehead, H. (2017), Characterizing alloparental care in the pilot whale (Globicephala melas) population that summers off Cape Breton, Nova Scotia, Canada. Mar Mam Sci , 33: 440–456. doi:10.1111/mms.12377

Bubble-Curtains: Ear Muffs for Harbor Porpoises - By Samantha Clark

If you have ever experienced a neighbor doing home improvements on their house, then you know the headache early morning construction can cause. Harbor porpoises face a similar problem with offshore wind farms being built. The foundations for these turbines require high-powered hammers which cause sonic sound waves when pounded into the sea floor. Unlike your neighbor who may knock on your door and warn you of the noise, unsuspecting porpoises in the wind-farm areas temporarily lose their hearing, making them vulnerable to predation. The noise also drives porpoises far from home, sometimes at distances of ten to fifteen miles. Germany and the United States recently made regulations specifying construction can emit no more than 160 decibels of sound during projects requiring these hammers. To put that into perspective, Boeing jets taking off emit a sound of 165 decibels and the human eardrum breaks at 160 decibels.

Scientist Michael Daphne and his team in Germany worked with DanTysk Offshore Wind Farm to help reduce noise disturbance for harbor porpoises while they built 80 turbines. One of the tools used was a Seal Scarer which was originally designed to make noise that deters seals but proved to be useful for porpoises too. They also used a pinger with a similar sound frequency to porpoise calls so the porpoises could hear the warning and turn around before the construction noise was unbearable. They even used bubble curtains. Traveling through an air bubble curtain made from compressed air in a tube, sound waves are reduced because air is less dense than water. Bubble curtains covering a .099-mile radius around the construction ensured porpoises were protected from every direction. Meanwhile, scientists monitored the local porpoises to see how they responded. They found the bubble curtains muffled the noise and contributed to less habitat loss because it allowed the porpoises to stay closer to the noise. The pingers and Seal Scarers helped porpoises avoid hearing loss but the Seal Scarers were just as bad as the construction at keeping the porpoises far from home.

Overall the project was successful but using Seal Scarers is being reevaluated. If you go to enough rock concerts, it’s inevitable that after a while you would have some permanent hearing loss. Similarly, when porpoises are exposed to multiple noisy projects, the scientist suspect it could have a larger effect on porpoise populations. The methods described by these scientists could help other developers to construct their alternative energy without disturbing marine life. Besides, it’s what a good neighbor should do.

For more information, check out the original scientific paper:

Daphne, M, et al. “Bubble Curtains Attenuate Noise from Offshore Wind Farm Construction and Reduce Temporary Habitat Loss for Harbour Porpoises.” Marine Ecology Progress Series, vol. 580, 2017, pp. 221–237., doi:10.3354/meps12257.

The Sham of Shamu: The Effects of Captivity of Orca Whales - By Jessica DeBenedetto

When killer whales (Orcinus orca), also known as orcas, are mentioned the first thing people think of is SeaWorld. Orcas being very social animals that usually travel in pods with anywhere from 5 to 100 orcas, placing these whales in captivity does not allow them to socially travel with other orcas. These whales in captivity “cannot swim one hundred miles a day, breed and care for their young, socialize in kinship communities, play freely, hunt at will, or die of old age” (Schutten & Burford 2017). Taking any animal out of their natural habitat for educational benefits does not justify imprisoning them, their natural behavior will not be observed and learned, the adaption to living in a fishbowl is what will be learned. The second we take those whales out of the ocean they become prisoners. The largest captive whale weighed 12,500 pound and measured 22 feet in length, his name was Tilikum and he spent his thirty-five years of life in captivity living his days and nights in a tiny swimming pool.

Tilikum is one of the most known killer whales for his starring role in Blackfish. To SeaWorld, Tilikum was a breeder, trainers manipulated him sexually to collect his sperm to produce more captive born calves to train and sell. With being held in captivity for more than thirty years, performing Tilikum was bound to become agitated and aggressive not just towards the other whales in the tanks but towards the trainers too. Food was used as a reward, perform as the trainer wants and fish will be rewarded. These whales in captivity are completely dependent on the trainers to provide them with basic needs of survival: food and water. Orcas that live in capacity are not only mentally affected they are physically affected too. All adult male dorsal fins collapse, which can be a result of not having enough space to swim and their unnatural diets.   Tilikum reached a point where he became so aggressive and killed three trainers.  In 1991 trainer Keltie Byrne was pulled underwater and ultimately drowned, in 1999 Daniel P. Dukes was drowned and it was not until 2010 when Dawn Brancheau was dismembered and drowned that his actions were taken seriously. After the death of Dawn, Tilikum was placed in a tiny isolated enclosure where there was minimal space to swim, and no communication with other whales or interactions with humans. Captive whales have a much shorter life expectancy than whales in the wild. In January 2017 Tilikum passed away of a bacterial pneumonia.

Tilikum was not the only killer whale to lash out at trainers; SeaWorld has documents of over 100 incidents of injuries trainers obtained from agitated whales. Kasatka, another orca, repeatedly pulled trainer Ken Peters underwater by the leg during a live show. The death of trainers caused by whale aggression led to protests for SeaWorld to release the captive orcas back into the wild. Tilikum has been said to be a martyr for his cause, calling attention to the fact that if an animal is used for entertainment there will be consequences. As of March 2016 SeaWorld officially ended captive orca breeding, the orcas they have are the last orcas SeaWorld will have. In California live shows will be phased out.

For more information, check out the original scientific paper:

Julie “Madrone” Kalil Schutten & Caitlyn Burford (2017) “Killer” Metaphors and the Wisdom of Captive Orcas, Rhetoric Society Quarterly, 47:3, 257-263, DOI: 10.1080/02773945.2017.1309911

A Guide to the Harbor Porpoise’s Diet - By Brie DeSoto

Marine mammals are fun to observe (from a safe distance) in their natural habitat. But there’s one aspect of their lifestyle we don’t often get a chance to see. What is that you ask? Hunting for food. It’s difficult to observe what exactly marine mammals eat because they dive into the deep water to hunt for food. Therefore, to understand what the diet of a marine mammal looks like, other methods need to be used. Having an understanding of what types of fish and other prey marine mammals consume can help with fishery and marine policy management. In order to get a better understanding of the marine mammal diet, you also need to know how much they’re eating in a given time. A group of researchers set out to collect data in order to find the diet composition and consumption rate of harbor porpoises’, a common marine mammal, in the western Baltic Sea.

In this study, Andreasen et. al (2017) spent 32 years collecting samples and data from harbor porpoises. These porpoises were already dead—either from stranding (becoming stuck on beaches) or from net entanglement. A total of 339 harbor porpoise stomachs were sampled (Andreasen et. al, 2017). Now in most cases, the porpoises’ last meal was already digested, but a key part of the food was still left in the stomach. What is that part exactly? The ear bone. That’s right folks, fish do in fact have ear bones— which are actually called otoliths. Otoliths are unique, which means a fish species can be identified by its ear bone. The researchers compared the otoliths they collected from the porpoises’ stomachs to those in a collection of 50 identified otoliths of various fishes. The researchers found that cod, herring, and gobies were the main prey for harbor porpoises in the western Baltic Sea. For adults, their diet consisted more of cod and herring, while juveniles also preyed on gobies (Andreasen et. al, 2017).

Overall, the researchers found their results matched the results of previous studies done on the diet of harbor porpoises in the North Sea and other nearby areas (Benke et al1998, Santos and Pierce 2003, Jansen et al2013, Leopold 2015). This said, if harbor porpoises are consuming mostly cod and herring, those fisheries will need to adjust their management in order to take into account how much the porpoises are taking from the stocks. This would help keep the cod and herring stocks from decreasing rapidly and being unable to recover.

For more information, check out the original scientific paper:

Andreasen, H., Stine, R., Siebert, U., Andersen, N., Ronnenberg, K., & Gilles, A. (2017, May 31). Diet composition and food consumption rate of harbor porpoises (Phocoena phocoena) in the western Baltic Sea. Marine Mammal Science, 33(4), 1053-1079

Boaters Beware - By Coltan Downey

The Gulf of Maine is full of recreational and commercial vessels but is also home to the southernmost feeding ground of Humpback Whales. This overlap of human activity and primary feeding ground for whales means that at some point, a boat and whale will unfortunately cross paths. Collisions with whales have been an important factor impeding the rebuilding of the protected humpback whale population but sadly, there are no current regulations in place to reduce the likelihood and frequency of collisions except for whale watching vessels.

Because boat strikes on whales go underreported in Maine, Alex Hill and five other conservationists and biologists decided to find out how many humpback whales have collided with vessels in the Gulf of Maine. The group of scientists analyzed 210,733 high resolution images of 624 humpback whales, which were used for identification purposes by the Whale and Dolphin Conservation from 2004-2013, in order to determine how many of the individuals show signs of boat collision injuries. Similar studies have used this method to successfully evaluate the entanglement frequency of humpback whales in the Gulf of Maine.

The results of the study showed that 92 of the photographed whales (14.7%) have injuries consistent with those from collisions with vessels with some individuals having 2-4 injuries across their bodies. These results are underestimated considering strikes resulting in blunt force trauma or mortality could not be detected, the percentage is possibly much larger.

This study also discovered that adult humpback whales are much more prone to injuries from collisions with vessels given the frequency of injuries is higher for adults than calves and juvenile whales. Hill’s study states that foraging behavior could be the cause of the high frequency of adult whale collision injuries. The study cites Weinrich et al.’s 1997 study which discovered that adult humpback whales tend to capitalize on prey found in the upper water column, which could be why vessel strikes are so prevalent.

The humpback whale population has been growing recently due to conservation efforts, however, these efforts must continue in order to ensure the success of many marine mammal species. In 2008 the National Marine Fisheries Service (NMFS) implemented vessel speed restrictions in order to decrease the frequency and severity of boat collisions with North Atlantic Right whales. These speed restrictions were created to protect the right whales but were said to offer additional protection to humpback whales however, humpback whales did not see any significant benefit or protection.

In order to reduce the frequency of whale collisions with vessels, public education campaigns such as the “See a Spout, Watch Out!” campaign which was developed by Whale and Dolphin Conservation with the help of the National Oceanic and Atmospheric Administration (NOAA). These campaigns help educate boaters about the significance their presence in the Gulf of Maine can have on the beautiful wild life. Education and outreach campaigns are great for educating the public but Alex Hill recommends restrictions and regulations on vessels operating in known whale habitats in order to protect the humpback whales and other marine mammals in the Gulf of Maine.

For more information, check out the original scientific paper:

Hill, A. N., Karniski, C., Robbins, J., Pitchford, T., Todd, S. and Asmutis-Silvia, R. (2017), Vessel collision injuries on live humpback whales, Megaptera novaeangliae, in the southern Gulf of Maine. Mar Mam Sci, 33: 558–573. doi:10.1111/mms.12386

Even Some Whales Think There’s No Place Like Home - By Mimi Edmondson

Just like Dorothy reminded us in The Wizard of Oz, there’s no place like home. As a new study suggests, Blainville’s beaked whales off Portugual’s Madeira Archipelago in the northeast Atlantic seem to think so, too.

In the study by Ana Dinis of the Center of Marine and Environmental Research of Madeira, she and her colleagues used photographs taken from whale-watching boats between 2004 and 2016 off the Madeira Archipelago in order to find out if there were any patterns of site fidelity.

Site fidelity is a term simply used to describe if an animal will tend to return to or remain in a particular area over a period of time. Understanding Blainville’s beaked whale site fidelity is especially important because of their high sensitivity to human disturbances, like noise. Manmade noises, like those emitted from naval sonars, are known to change the behavior of beaked whale species. They leave the area where there is noise disturbance, sometimes stop eating, and in severe cases become stranded (or stuck) on a beach and die.

There was evidence of both short-term and long-term site fidelity for these whales. Site fidelity was short-term when an individual whale was seen many days in the same area during the year, and long-term was when an individual was seen on multiple days over many years. This is one of the first studies to successfully show that there is site fidelity of the Blainville’s beaked whale off the Madeira Archipelago.

What makes the waters off the Madeira Archipelago such an important habitat for Blainville’s beaked whales? Scientists believe that it offers different benefits for each sex. Females rely heavily on the area primarily to feed, while males rely mainly on the groups of females that cluster there for opportunities to mate.

A notable case of a Blainville’s beaked whale stranding occurred on the Canary Islands in 2002. This stranding event was linked to sonar use in the area. Although there has been no evidence of Blainville’s beaked whale strandings on the Madeira Archipelago yet, in 2000 a similar species, Cuvier’s beaked whales, stranded there likely because of naval sonar use.

This study should shed light on how important the Madeira Archipelago waters are to Blainville’s beaked whales, demonstrated by their site fidelity. Hopefully policymakers will take this information and use it to better regulate the planning of military sonar practice in the vicinity of this important habitat. Minimizing the amount human-produced noise disturbance will likely prevent a devastating stranding event of Blainville’s beaked whales in this essential habitat off the Madeira Archipelago.

For more information, check out the original scientific paper:

Dinis, A., Marques, R., Dias, L., Sousa, D., Gomes, C., Abreu, N., and Alves, F. “Site Fidelity of Blainville’s Beaked Whale (Mesoplodon densirostris) off Madeira Island (Northeast Atlantic).” Aquatic Mammals. Vol. 43, no. 4, 2017. pp. 387-390

Are Ship Strikes Preventing the Recovery of North Atlantic Humpback Whales? - By Tarren Giberti

Humpback whales are best known for breaching out of the water, and their beautiful melodious songs that consist of cries, moans, and howls. This species of whale is often a favored subject for whale watches around the globe.

Unfortunately, ship strikes may be inhibiting the recovery of the North Atlantic humpback whale population. To address this question, a team of scientists studied humpback whales in the Gulf of Maine. This region has an overlap between humpback whale territory, and high commercial and recreational ship activity. There have been frequent reports of whales that appear to have been injured by ship strikes. However, these reports are typically after the injuries have occurred, with no knowledge of where and when they originated.

The team of scientists organized by Alex Hill, used over 200,000 high resolution photos collected from research and commercial whale-watching boats. It was determined that 624 individual humpback whales could be identified from the photos, where 92 showed injuries. Scientists examined the photos to determine injuries that resulted from ship strikes, and how often these injuries occur. An injury was determined by the appearance of physical trauma to a whale, such as cuts and damaged fins. The severity of each injury was also able to be determined based on the state of healing. Adult humpback whales have the highest risk for being injured by a ship strike due to their larger body size compared to when they are young.

There’s been a problem with people not reporting whales struck by ships. Researchers are not sure why people are neglecting to report whale strikes, but it likely has to do with a fear of getting in trouble for the event. The ultimate conclusion was ship strike injuries may have a potential role in the slow recovery of the humpback whale. Especially, where there are no current regulations by the government to prevent humpback whale strikes by ships. However, there are ship regulations for the highly endangered North Atlantic Right Whale that have been suggested to benefit other whale species. The National Marine Fisheries Service enforce speed regulations during the season that the Right Whales are present in the Gulf of Maine. Ships must keep a speed of 10 knots or less in these areas from January-July. Unfortunately, a study found that these regulations do not significantly benefit humpback whales, and that they continue to occasionally be struck by ships.

At the time of this study, which occurred from 2004-2013, humpback whales were listed as endangered throughout their range. The good news is, humpback whales were removed from the endangered species list just last year in 2016. However, care needs to be taken to prevent the re-listing of one of societies favorite whale species.

For more information, check out the original scientific paper:

Hill, A, N., Karniski, C., Robbins, J., Pitchford, T., Todd, S., Asmutis-Silvia, R. 2017. Vessel collision injuries on live humpback whales, Megaptera novaeangliae, in the southern Gulf of Maine. Marine Mammal Science. 33(2): 558-573.

Humpback Whale Population in the Gulf of Maine Threatened by Unreported Ship Strikes - By Faythe Goins

Humpback Whales were added to the endangered species list in 1970, driven close to extinction through years of commercial whaling. The majority of humpback populations are now rebounding thanks to the US Endangered Species Act, the US Marine Mammal Protection Act, and the International Whaling Commission. The combination of these regulations has helped to protect humpback whales as well as many other species and has essentially put a stop to the commercial whaling industry. However, these increased population sizes may also be a contributor to an increased number of whale and boat interactions. This is especially true in the Gulf of Maine, in which the humpback whales’ primary feeding ground and feeding time overlaps with recreational and commercial boating activity in the area. The large majority of these ship strikes go unreported, and until a recent study by Alex Hill and her colleagues, it was unknown just how many whales were affected by vessel collisions in this region.

This recent study, published in Marine Mammal Science, looked at high-resolution whale photographs taken by Whale and Dolphin Conservation to determine the impact of vessel strikes in the Gulf of Maine. Looking at over 200,000 photographs of 624 individual whales, multiple reviewers determined that approximately 14.7% of the photographed whales had been struck and injured by at least one boat. Severity of the wounds and stage of healing were also scored by the reviewers; they concluded that the majority of wounds were still in the healing process and were most often categorized as deep wounds penetrating the blubber.

This may seem like a low percentage to some, but it is important to realize that these results do not include those whales killed by vessel interactions and therefore only provide us with part of the story. A study by van der Hoop and colleagues found that the large majority of dead humpback whales are a result of human activities. Therefore, we should only consider the number of injuries as an indicator of how large of an impact we are potentially having on this species.

Apart from whale watching activity guidelines, there are currently no regulations designed to reduce humpback whale and vessel interactions. However, the results of this study suggest that measures need to be taken to reduce the number of vessel strikes upon humpback whales in the Gulf of Maine. Regulations could potentially allow the humpback whale population to continue to rebound as well as reduce human caused injuries and fatalities of the species.

Seasonal regulations have already been put into place in the area to protect the North Atlantic Right Whales, and have appeared to reduce the number of collisions. Therefore, there is hope that more regulations involving all vessel types may help decrease ship collisions with humpback whales in the Gulf of Maine.

For more information, check out the original scientific paper:

Hill, A. N., Karniski, C., Robbins, J., Pitchford, T., Todd, S. and Asmutis-Silvia, R. (2017), Vessel collision injuries on live humpback whales, Megaptera novaeangliae, in the southern Gulf of Maine. Mar Mam Sci, 33: 558–573. doi:10.1111/mms.12386

Beloved Sirenian Fighting For Its Life in the Waters Of the Atlantic Ocean, Caribbean Sea, and Gulf of Mexico - By Katie Golias

Manatees are herbivorous, free swimming, gentle giants that enjoy warmer climates and water temperatures. Historically hunted almost to extinction, today the species continues to face threats such as illegal overfishing, drowning while entangled in fishing nets, and changes to their habitats. These marine mammals are part of the order Sirenia. Sirenians are broken down into two families, the Trichechidae that include manatees, and the Dugongidae that include dugongs. Earlier this year, the West Indian manatee was classified as threatened with extinction by the Convention on International Trade in Endangered Species (CITES), and the Secretaria del Medio Ambiente y Recursos Naturales (SEMARNAT), and as vulnerable by the International Union for Conservation of Nature and Natural Resources (IUCN). Unfortunately, these innocent creatures have been dwindling in numbers and if no efforts of mitigating these threats are taken, the population may not recover.

Recently, researchers studying the West Indian manatee (Trichechus manatus) populations in Mexico reported on the devastating condition for this species. Only 121 manatees remain along the Alvarado Lagoon System (ALS) in the state of Veracruz, where past estimations place manatee populations to approximately 1,000 to 2,000 individuals. In the state of Quintana Roo, another once heavily populated area, the careful tracking and surveying of the manatees has concluded that approximately 250 manatees remain in this region (Serrano et al. 2017). West Indian manatees mostly like to congregate in these areas of warm waters and an abundance of food supply, thus making this the perfect spot to survey and estimate the current remaining population statistics.

Manatees truly are gentle giants as they do not compete with one another for food, other resources, or mating. As herbivores, they only eat sea grasses and other various algae. Human interference is a major cause of population declines as the only predators that face manatees are humans. Factors such as boat strikes, entanglement from fishing nets, ocean acidification, pollution, hunting or overfishing, and changes in the climate (which affect their habitats) are major influences that are causing recent population declines.

Utilizing a combination of visual, acoustic, and sonar techniques to count the manatees in the wild, the research team led by Dr. Serrano and colleagues was able to estimate the population density of the West Indian manatee in the ALS. During the research period between October 2008 to January 2011, they observed only 13 manatees. Researchers found that the species is slowly relocating or disappearing from the state, and that population size continues to plummet. They cannot help but conclude that the future local extinction of this mammal is upon us, as has already been observed in other regions of Mexico. That is why long-term observation and conservation is crucial for the survival and repopulation of this cherished manatee.

For more information, check out the original scientific paper:

Serrano, A., del Carmen Daniel-Rentería, I., Hernández-Cabrera, T., Sánchez-Rojas, G., Cuervo-López, L., & Basáñez-Muñoz, A. (2017). Is the West Indian manatee (Trichechus manatus) at the brink of extinction in the State of Veracruz, Mexico?. Aquatic Mammals43(2), 201.

Can Attempts to Save the Environment Harm Marine Mammals? The Tug-of-War Between Helping the Environment and Harming Harbor Porpoises - By Rochelle Gordon

As the health of the environment declines, more and more methods to combat negative effects of human impacts are being designed and implemented throughout the globe. But can some these modern technologies actually harm animals?

Offshore wind turbines are designed to create renewable energy and reduce harmful gas emissions. These sounds like beneficial effects, however, constructing wind turbines in the environment of marine mammals is bound to have an impact them. If the impacts on marine mammals are detrimental, at what point do the costs outweigh the benefits?

In a study conducted by Vallejo et al., researchers observed harbor porpoises in an area surrounding the Robin Rigg offshore wind farm, located in the Solway Firth in the northern Irish Sea. This is a vital habitat for harbor porpoises. Observations were made in the preconstruction, construction, and operational phases in the development of the farm. Observations were made by individuals from elevated viewing platforms on boats, with the help of high-quality binoculars. The abundance of harbor porpoises present in the area is a good indicator of the degree of the impact the wind farm has on these animals. While observing the porpoises in the preconstruction phase, researchers learned how many porpoises resided in the area. They then observed and counted the number of porpoises present in the construction and operational phases of the farm, to see if the abundance of porpoises changed significantly. If it had, the assumption that the wind farm had a severe and negative impact can be made. The goal of the researchers was to observe and measure the severity of the impact the development of wind turbines has on this species, and whether the effects are detrimental.

The study revealed that no significant difference in the abundance of harbor porpoises was found between the preconstruction and operational phases of the wind farm. However, a significant decrease in the number of these animals occurred in the construction phase of development. This is due to the noise pollution that is brought about by loud construction methods such as pile driving. These animals fled the area due to this noise pollution, but returned to the preferred habitat once construction ceased and the noise pollution ended as well.

The findings from this study tell us that wind farms do not have a considerable impact on marine mammals such as harbor porpoises. The construction of them, however, does have short term consequences in which quality habitat can be abandoned. This can be harmful to the species if they relocate to a habitat that is not as well suited for them as the one they left, even if it is only temporarily.

Sources of renewable energy such as wind turbines and marine mammals can coexist, if the construction phase is not too invasive on the marine ecosystem. To minimize the negative impacts on marine mammals, construction of offshore wind turbines should be done as quickly as possible, with methods designed to lessen the severity of noise pollution and disturbance to the surrounding habitat.

For more information, check out the original scientific paper:

Vallejo, Gillian C., et al. “Responses of Two Marine Top Predators to an Offshore Wind Farm.” Ecology and Evolution, vol. 7, no. 21, 2017, pp. 8698–8708., doi:10.1002/ece3.3389.

Are Humans Making Seals Lazy? - By Natalie Grimm

Human exposure may be making harbor seals less responsive to predators in the Salish sea. A study conducted by Olsen and Acevedo-Gutierrez (2017) studied harbor seals at low, medium and high human exposure levels, within San Juan Islands and southern Puget Sound of the Salish Sea in Washington. The human exposure levels were established based on the amount of boat traffic that was present around an area where seals tend to gather onshore. Their observations of harbor seal response, to the presence of a bald eagle predator at six study sites (2 low exposure, 2 medium, and 2 high) indicate that the seals are starting to become accustomed to human presence. As a result the seals are not as responsive to a predatory threat. Six behaviors of the bald eagle predator were observed, gliding, powered flight, landed, scavenging, and attack, in conjunction with three harbor seal behaviors. The three types of behavior observed for seals were, no reaction to predators, alertness, and flushing. Flushing occurs when a seal may be frightened on shore or feel threatened and moves to the water for safety. Olsen and Acevedo-Gutierrez found that seals at the high human exposure sites were less responsive to the presence of bald eagles than those at low exposure sites, and exhibited less alertness and flushing. They believed that this was because the seals at the high human exposure sites may be becoming less sensitive to the presence of unfamiliar things, like new sounds or objects. In essence the harbor seals are becoming lazy when it comes to responding to potential threats. Harbor seals’ increase to human tolerance is important in understanding how humans impact the activity of the seals as it may make them more vulnerable to predation. The researchers did acknowledge that further studies looking at the proportion of adults, juveniles, and pups at seal resting locations on shore would help to further our understanding in human impact on seal predator response, as the presence of pups may cause the seals to be more alert. Nonetheless, the findings of Olsen and Acevedo-Gutierrez (2017) are important in determining how human presence effects harbor seal risk of predation. In addition, the study helps us to recognize how important it is for us to understand how humans impact natural predator-prey relationships.

For more information, check out the original scientific paper:

Olson, J.K., Acevedo-Gutiérrez. 2017. Influence of Human Exposure on the Anti-Predator Response of Harbor Seals (Phoca vitulina). Aquatic Mammals. 43(6): 673-681

Bags, Bullets and Boats - Marine Mammal Plight - By Holland Haverkamp

You might not think that injury and death from gunshot would be a significant risk to seals and sea lions, especially since harming them is strictly prohibited. But as it turns out it, it is all too common.

In a study recently published in the journal Marine Mammal Science, a team of researchers analyzed marine mammal stranding reports on the central Californian coast for a 12-year period from 2003-2015, to categorize what most puts them at risk. Gunshots, they found, are a major contributor. Just to take a step back, a stranded animal is one which is outside of its natural habitat, and potentially at risk of death. With well over 10,000 reports of stranded marine mammals, lead author Daniela Barcenas-De la Cruz, from The Marine Mammal Center, and the other researchers focused their attention on those stranded animals that suffered from anthropogenic trauma – that is, from injury attributed to humans.

617 animals, or 6% of all strandings suffered from some type of anthropogenic trauma. These types were categorized as gunshot; fishing tackle, which included the presence of a hook, lure, or pot; boat collision; and marine debris, or trash.

“Marine debris has become the most common anthropogenic interaction in the past years,” said Barcenas-De la Cruz. This surprised the authors, who fashioned the study to match a previous study from the late 1980’s and early 1990’s by Tracey Goldstein. “We figured it will be practical to give it some continuity and make the data comparable by using the same criteria.” This way, not only could they look at what forms of trauma most affected the seals, sea lions, dolphins and whales that strand in their study area, they could also analyze how these causes have changed over time. With the exception of gunshots, which decreased over time, every other source of anthropogenic trauma increased from the first study to the second.

The other thing that most surprised Barcenas-De la Cruz and her collaborators? “The high prevalence for Guadalupe fur seals, since they are not residents of the area. It will be interesting to know what is going on in their usual habitat that is making us see them more in non-usual locations.” Given the habitat shift, she does not at this point know where they are becoming entangled – are they finding the debris in California or bringing it with them from Mexico. Answering questions like this could have real management implications for this species and others.

In addition to the mystery of the Guadalupe fur seals, which is one area where they hope to see further research, Barcenas-De la Cruz sees other potential management implications from the data collected. Marine mammals are very visible indicators of marine health, and can help illuminate the impact humans are having on the marine ecosystem. “I hope it can also make us realize how our activities are making an impact in the marine mammal populations and to look for better alternatives.”

For more information, check out the original scientific paper:

Barcenas-De la Cruz, D., DeRango, E., Johnson, S.P., Simeone, C.A. (2017). Evidence of anthropogenic trauma in marine mammals stranded along the central California coast, 2003-2015. Marine Mammal Science, doi:10.1111/mms.12457.

Goldstein, T., Johnson, S.P., Phillips, A.V., Hanni, K.D., Fauquier, D.A. (1999). Human-related injuries observed in live stranded pinnipeds along the central California coast 1986-1998. Aquatic Mammals, 25, 43-51.

What do female killer whales and women have in common? - By Rachel Howland

Killer whales are beautiful creatures just like women. Although very different, these two have something in common. What could it possibly be? Other than the fact that they are both mammals, both experience menopause. But when you hear the word menopause, most people will immediately think of it being the age where a woman becomes infertile, or no longer can have children. But have you ever thought about a killer whale going through menopause? Yes, you read that right, killer whales also go through menopause. Killer whales have “the longest post-reproductive lifespan of all non-human animals” (Croft et al 2017). Probably your next questions are “why do females go through menopause?” or “what other animals experience this?” and “why killer whales?”

For the first question, there isn’t really any verified reason why this happens, but there are a few hypotheses. The one that is most common is the “grandmother hypothesis”. This states that menopause occurs so the older female can help care for her children and grandchildren to increase their chance of survival. For the second question, the only other animals known to go through menopause other than humans and resident killer whales, are pilot whales.

There was a recent study conducted using data/photographs, from Washington State and British Columbia to answer your last question, “why killer whales?” This study was conducted by biologist/behaviorist Dr. Darren Croft from the University of Exeter in the UK. He hypothesized that there may be a reproductive competition between the mother and daughter. Another thing Dr. Croft noted is the oldest female in a pod is most likely related to a majority of the other individuals in the pod since they are her offspring. In contrast, the younger females are the least related since father killer whales belong to another family group. An interesting fact is the females live longer than the males, which only live to about thirty while the females live on into their forties. Although, as females got older, their calves would generally be born into reproductive conflicts with almost two-times higher death rates than that of offspring of younger females, but Dr. Croft is unsure of why this happens.

In the end of the study, Dr. Croft finds that their models and data support the grandmother hypothesis. By caring directly towards sons, the older females can ensure their sons fitness. Additionally, the results supported the hypothesis that the costs of reproduction (costs such as competition and calf survival) for female resident killer whales at a later age are high. This research is exciting because it could eventually tell us what the benefit of menopause is for females.

For more information, check out the original scientific paper:

Croft, D. P., Johnstone, R. A., Ellis, S., Nattrass, S., Franks, D. W., Brent, L. J., Mazzi, S., Balcomb, K. C., Ford, J., Cant, M. A. (2017, January 12). Reproductive Conflict and the Evolution of Menopause in Killer Whales. Current Biology 27(2), 298-304. Retrieved from https://www-sciencedirect-com.prxy4.ursus.maine.edu/science/article/pii/S0960982216314622.

There’s a New Sheriff in Town – Humpback Whales are Stopping Killer Whales from Attacking Other Marine Mammals - By Tal Kleinhause

Out of all animals to ever live on Earth, whales are by far the biggest, and the most mysterious of them all. Spending most of their time in the depth of the ocean, there’s still much we don’t know about whales – the things they eat, how they choose where to migrate and how they interact with each other or with other species.

However, being so big means you’re bound to be noticed from time to time. Which is exactly how some scientists started to notice an interesting interaction between Humpback and Killer whales: Humpback whales (a baleen whale that feeds mostly on krill) become united to mob around Killer whales (a toothed whale feeding on marine mammals like the Humpback) when those are hunting for marine mammals, attacking the predator and setting the victim free.

Recently, a group of scientists from all over the world combined forces to look further into this phenomenon. In an article published in the “Marine Mammals Science” journal, those researchers, led by Dr. Robert Pitman, have collected evidences of Humpback-Killer interactions, and concluded that cases of Humpbacks ganging up against Killer whales are much more common than we think.

According to the study, Humpback whales are responding to the sounds of Killer whales attacking other marine mammals by gathering around him as a group and use their powerful tail and flippers to scare the Killer whale away. Humpbacks respond to this call for the rescue without even knowing if the victim is another Humpback whale or not. What’s even more impressive is the fact that according to the study, in 89% of the cases where Humpbacks interfere with a Killer whale attack, the prey in question wasn’t a fellow Humpback after all.

It’s very unusual for one animal to risk its life in order to rescue another animal, especially when they’re not closely related, let alone from a different species. And so now scientists are now thinking there’s more to the relationships between Humpbacks and Killers than just a regular predator-prey conflict. As part of Dr. Pitman’s study, the team concluded based on Humpbacks scares that Killer whale attacks are fairly common, with most of them aimed towards young calves.

This led researchers to believe that the potential danger from Killer whale is one of the main reasons why Humpback whale choose to give birth in southern areas of the ocean, where there’s less food but also less predators. This might also be the reason why nursing moms take different, closer to shore, routs with their young as they migrate up north.

As we gain more knowledge about the natural balance in the marine world, there’s still much to learn about whales and their ecosystem. Generally, whales are considered to have no natural predators, with whaling the main cause for the decline in their population. As the whales continue to recover, we can discover more about the way things were before whaling, and the way other species might be affected by these changes at sea.

For more information, check out the original scientific paper:

Pitman, Robert L., et al. “Humpback Whales Interfering When Mammal-Eating Killer Whales Attack Other Species: Mobbing Behavior and Interspecific Altruism?” Marine Mammal Science, vol. 33, no. 1, Jan. 2017, pp. 7–58.

Are Dolphins Watching What They Eat? - By Jessica Laplante

Recent studies have shown that the health of bottlenose dolphins (Tursiops truncatus) can serve as an indicator of the hazards and potential threats in the marine environment. Up until now, the convenient and accurate way of testing a dolphin’s health was comparing biological and physiological measurements, such as weight, length, and girth, which is the measurement around the midsection of the animal, to known reference intervals (RI’s), which are ranges of values often considered normal for the species, which include weight and length. These intervals are influenced by different factors such as age, gender, and reproductive condition, and they are often used on humans to determine what is “normal” in terms of health. These comparisons had to be done manually, to assess the stress on the animals after field data collection. The problem was, the data collection had to be performed after the fact, which is not effective, especially if their data is dependent on the health of the animal.

Recently, Leslie B. Hart and her team developed a cloud-based programming application for their mobile devices, that would perform the comparison of dolphin data to the RI ranges at the touch of a button. The app would come programmed with short-term storage of data collected during field assignments, eliminating the written portion. The app would be user-friendly, having only a few text boxes for data input and output to be displayed, and all numbers would be converted to the right units to go along with the RI values.

The team performed an experiment on a population of dolphins within a 500×4 meter net, collecting blood, then placed in a sling for transport onto the boat, where they were weighed and measured. The values were then entered into the app to be calculated. They were also done manually to test the app’s accuracy. The results were compared, to find that they were 100% accurate between the app’s numbers and the manually calculated numbers for weight, length, and the length of the animal’s midsection (girth). The app proved to provide a user-friendly framework that connected events, including calculations based on user input, and steps to identify individuals that did not meet the normal range of RI values.

The results from this study found that the dolphins tested showed that among the dolphins with poor body condition, there was evidence from human interaction (e.g. fishing gear ingestion) or marks of being stung by stingrays, both of which impact the feeding efforts of the dolphins.

The ability to identify the individuals that have poor body condition in real-time could greatly improve veterinary evaluations by showing overall health before the animal is released. It is also the hope that this app will help minimize the number of discrepancies that happen during data collection or transcription, and automate data storage using cloud-based mechanisms, much like the public is familiar with in most smart phone technology. It is truly a revolutionary step in the understanding of marine mammal health.

For more information, check out the original scientific paper:

Hart, Leslie B., et al. “Rapid Assessment of Bottlenose Dolphin (Tursiops truncatus) Body Condition: There’s an App for That.” Aquatic Mammals, vol. 43, no. 6, 2017, pp. 635–644., doi:10.1578/am.43.6.2017.635.

The many voices of dolphins and whales - By Mikayla McFetridge

When someone says you can identify certain species by the noises they make, much like a person can tell who another person is by the sound of their voice, you may ask how? Some voices are lower, some more high pitched. Some voices are fast paced and others are slower. It is easy to distinguish different groups of animals based on the noises they make such as whales and dolphins which use a series of clicks, whistles and quick bursts of noises . Each group makes their own specific type of noise. With new technology and research, scientists are beginning to be able to identify not just what type of organism is making the noise, but the exact species. They are able to take a group of noises and pick out the specific species in the sample, just like listening to a song and being able to tell which instruments are being used.

Shannon Rankin, from the National Oceanic and Atmospheric Association, decided to conduct a four and a half month experiment using a new method for identifying the species, in the water around a vessel, using only the sound that is captured. This new method is called BANTER, or bio-acoustic event classifier which is a mathematical model created using the noises of five species of dolphins off the western coast of the united states. The species used to develop BANTER were the long-beaked common dolphin, Risso’s dolphin, Pacific white-sided dolphin, Pilot whale and Killer whales. The experiment was conducted in the U.S exclusive economic zone. The sounds recorded were looked at by a sound technician that would then try to identify the species that was present. Visual observers on deck would record the species that were actually able to be seen and identified for comparison. Over two million noises were captured over the course of the experiment. The expected percent of correct classification was 39% the actual percentage was 84%. This means that the scientists were able to correctly identify an average of 84 out of 100 samples.

The purpose of this experiment and the development of BANTER is for survey teams to be able to identify species in an area that is being explored. This will be helpful when oil companies and other businesses want to use a part of the ocean but are not aware of what species they will be disturbing. With this tool they will be able to record the exact species they will be impacting in the area. This will also make it easier for people issuing permits to tell if the area is habitat to an endangered mammals. Until now species were only able to be identified by visual surveys. This method is not always the most accurate simply due to different species behavior. Some species are more social and will show themselves when a vessel is near, other will hide from the vessels and make it seem as though there are no species present. Technology is changing every day and making things that once seemed to come from science fiction into fact.

For more information, check out the original scientific paper:

Rankin, S., Archer, F., Keating, J. L., Oswald, J. N., Oswald, M., Curtis, A. and Barlow, J. (2017), Acoustic classification of dolphins in the California Current using whistles, echolocation clicks, and burst pulses. Mar Mam Sci, 33: 520–540. doi:10.1111/mms.12381

Humpback Hero - By Mackenzie Menard

Us humans tend to stick together and look out for the little guy. It seems like humpback whales may have this same mentality when it comes to protecting small marine mammals from predators, especially from the notorious killer whale. In a recent study conducted by Robert Pitman and his many colleagues, these mammoth whales had been observed to come to the rescue of distressed mammals. These mammals included other whales (mainly humpback and gray), porpoises, seals, sea lions, and even a large fish! Observational data was collected from a large number of sources; scientists, common folk, and naturalists all provided information which was included in the study. The data collection spanned 62 years and included data worldwide, though most cases were found on the American west coast.

In many of the observations, these humpbacks were seen performing the same behavior towards the orcas as two male humpbacks might do to each other while competing for a mate. As described by Pitman and team as mobbing behavior, the whales would slam their flippers and tail flukes against water surrounding the orcas, chase the orcas, and make intimidating snorts. The humpbacks were never seen to come in direct contact with the orcas. Out of all of the observed interactions between humpbacks and killer whales, 38% of prey survived the attack because of the humpbacks intervention. However, the outcome of the attacks were unknown 33 times out of 115. Of the known outcomes, 54% of the prey survived.

The reason that the humpbacks try to drive off the killer whales is still unknown. Like most subjects in ecology, understanding “why?” is the hardest part. Only 11% of the interactions involved the humpbacks trying to protect a member of its own species, usually calves or lone whales. That leaves 89% of the interactions dedicated to saving a species entirely separate from their own. The whales exerted a significant amount of energy in order to save marine mammals. Initially, they have to travel (likely out of their way) to the site of the attack. A group of whales were even seen to travel up to 7.5 kilometers to come to the aid of a gray whale in need. Once they arrived on scene, the mobbing behavior required quite a bit of energy as well. It was concluded in the study that these whales are likely acting altruistically, or selflessly.

For more information, check out the original scientific paper:

Pitman, Robert L., et al. “Humpback Whales Interfering When Mammal-Eating Killer Whales Attack Other Species: Mobbing Behavior and Interspecific Altruism?” Marine Mammal Science, vol. 33, no. 1, Jan. 2017, pp. 7–58.

Facial Recognition: Not Just for Technology - By Alicia Miller

Who would have thought that cell phone technology would be the key to dolphin science? With the newest advances in technology today people can secure their electronic devices using a mode of facial recognition. Could the same approach be used to increase the accuracy of science? When conducting scientific surveys in the marine world, it is often important to be able to distinguish an individual animal from the vast majority of the other members of the population, just as the newest iPhone can supposedly distinguish its owners’ face from all other members of the human race.

When identifying mammals in marine environments, researchers often look at the unique characteristics that can be found on the dorsal fin and tail flukes of the animals. However these markings can fade and change as an individual matures, making them less reliable indicators. A need to find a more accurate way of identification for these marine mammals sparked a recent study in the Gulf of Trieste and its’ surrounding waters. A research team led by T. Genov found that bottlenose dolphins had distinct facial features and symmetry as calves that were unchanging into their adulthood.

With the help of high powered cameras, researchers collected 2,318 photographs which showed a large amount of detail in the facial features as well as the dorsal fins of the bottlenose dolphins. To test the accuracy of dolphin facial recognition, 27 biologists (some of them with identification experience, and others without) were recruited to play a matching game. Could biologists identify the 31 individual dolphins by matching images of the left and right sides of the face as well as the dorsal fin?

In fact, the study reports that not only did biologists with identification experience do better than those without experience but it was also determined that symmetry between the two sides of the dolphins’ face allowed for accurate matching and identification.

Through the process of comparison of photographs over time, Genov and his research team were able to determine that facial features in calves hold true over time and can be used to accurately identify individuals even after they are weaned from their mothers and disperse. Based on these studies, it seems safe to assume that dolphins use visual cues such as facial recognition to identify their counterparts in close proximity, just as we humans use facial features to recognize one another.

For more information, check out the original scientific paper:

Genov, T., Centrih, T., Wright, A. J. and Wu, G.-M. (2017), Novel method for identifying individual cetaceans using facial features and symmetry: A test case using dolphins. Mar Mam Sci. doi:10.1111/mms.12451

Are Boat Collisions a Serious Threat to Humpback Whales? - By Jordan Morace

Humpback whales are probably the most famous whales, however, according to Hill et al., they are also among the most prone to being hit by boats. Even though Humpbacks, as a species, are making a comeback, they are presently listed as endangered under the U.S. Endangered Species Act, and since they are a strategic stock, which is the idea that human’s involvement in killing this species exceeds the maximum that it should be, they are presently protected under the U.S. Marine Mammal Protection Act. In response to both this and the North Atlantic Right Whale needing protection, the National Marine Fisheries Service set speed restrictions for boats, so that they might be able to reduce the threat of collisions with animals. It is believed that collisions between Humpbacks and boats is detrimental to the recovery for this species. Although it has been incredibly beneficial for the North Atlantic Right Whales, it has not been all that useful for the Humpbacks.

The Gulf of Maine is the Humpback’s southernmost feeding ground, and it overlaps with both commercial and recreational boating activity. There has been an increase in injuries from boats, primarily from the propellers. These injuries can range from minor, skin only or skin and blubber lacerations, which accounts for 95% of injuries, to extending to the muscle. Most, if not all, of the whales with injuries extending to the muscle eventually die due to its severity. 14.7% of the 624 whales studied had some form of injury, and while this may not seem like a lot, many necropsies of whales reveal that the animal died due to a collision with a boat. Most of the whales that had sustained injuries were female, and were either adults or calves. Interestingly, juveniles did not get injured as often. Usually there was only one injury, but some did have up to four or five. 86% of these injuries were on the whales tail and back, both of which are the primary body parts for breaking the surface of the water, and are seen, when a whale is surfacing to breathe.

As scary as Humpbacks experiencing life-threatening injuries from these collisions is, it can be rest assured, however, that going out to see these animals on a whale watch will likely bring no harm to these animals. Hill et al. explains in his article that not only vessels that are carrying paying costumers are the vessels that are least likely to hit Humpbacks, but these vessels are also playing an integral role in educating people about the animals, and are making major contributions to research by being out there and observing the whales. Whale and boat collisions are often times under reported, with only one report between 2004 and 2013. Often times the collisions are underestimated due to undetected events, and the most likely perpetrators of this include commercial fishing vessels, recreational vessels, and other small boats. Hopefully, Hill et al.’s research will aid in creating more protections for this species.

For more information, check out the original scientific paper:

Hill, A. N., Karniski, C., Robbins, J., Pitchford, T., Todd, S., & Asmutis-Silvia, R. (2017). Vessel Collision Injuries on Live Humpback whales, Megaptera novaeangliae, in the Southern Gulf of Maine. Marine Mammal Science, 33(2), 558-573. doi:10.1111/mms.12386

Shellfish - Are They In The Dolphin’s Way? - By Sammi Nadeau

GALICIA, NW Spain— Mediterranean mussels, classically prepared with olive oil, white wine, garlic, and a dash of red pepper flakes are a simple, yet elegant dish revered by the common foodie and the chefs who prepare them. Demand is high, they are remarkably easy to farm, and as a result they are cultivated all throughout the coastal waters of northwestern Spain, but do all of those ropes, boats, and rafts pose a threat for our beloved bottlenose dolphins?

Aquaculture, or the farming of marine plants and animals, has become increasingly popular over recent years. Fish and shellfish farming are two of the most common forms.

Galicia, Spain is dominated by old submerged tectonic valleys called ‘rias’, which have an abundance of food and nutrients; the ideal location for shellfish farming, especially mussels.

Bruno Diaz Lopez, lead scientist at the Bottlenose Dolphin Research Institute, is studying the presence of coastal farms and their impact on the common bottlenose dolphin (Tursiops truncates) off the Ria of Arousa – the largest ria in Galicia. Diaz and his team observed the behavior of bottlenose dolphins in the farmed area and identified potential hazards because the interaction between aquaculture and dolphins has gone largely understudied.

These mussels are grown using a ‘batea’ – large floating rafts made of connected eucalyptus trusses to create a large rectangular platform. Aside from the equipment anchoring the trusses to concrete blocks on the sea floor, 500 ropes are suspended 40 feet below the surface to allow for mussels to attach.

Galician waters are responsible for 98% of the total Spanish production, 50% of the European production and 13% of the global production. Galicia harvests 300,000 tons of mussels annually, which is nearly the weight of the empire state building.

During Lopez’s study, at least three observers would stand watch on a boat moving along the coastline between 6 and 8 knots (about 7-9 miles per hour), searching for aggregations of dolphins near the farm. Researchers suspected that dolphins were attracted to the farms because of the large groups of fish that surrounded the rafts. This study lasted just short of 2 years and the coastlines were observed over four seasons: Winter (January to March), Spring (April to June), Summer (July to September, and Autumn (October to December).

The results of this study suggest that shellfish farms are popular spots for the common bottlenose dolphin to hangout. Of the observed 369 cetacean (whales, dolphins and porpoises) interactions, 353 were with the common bottlenose dolphin, 11 were with the harbor porpoise, 4 were with common dolphins, and 1 was with Risso’s dolphins. With this, Lopez and his team concluded that the increase of common bottlenose dolphin sightings was, in fact, related to the presence of the mussel farms and the dolphins appear unperturbed.

For more information, check out the original scientific paper:

Lopez, B.D., Methion, S. 2017. The impact of shellfish farming on common bottlenose dolphins’ use of habitat. Springer, Marine Biology (2017) 164:83. http://www.thebdri.com/resources/downloads/diazmethionmarbiol2017.pdf

Milk produced by pregnant and nursing porpoises - By Kristina Nelson

During and after pregnancy, it is crucial to not interfere with how a mother cares for her offspring. However, lactation is one of the most important components for reproductive success, and understanding how milk composition varies from birth to weaning is equally as important. Remarkably, researchers have begun to study such questions in wild marine mammals – a risky and difficult process! A recent article published in the Journal of Marine Mammal Science in July 2017 sheds light on their discoveries.

Scientists were interested in understanding how milk composition varies across the duration of time that a mother lactates to feed her young by studying two finless porpoises – one which was common to marine environments and the other which is exclusive to the Yangtze River. Scientists examined numerous components that were important to the composition of milk, including how their diet of fish, shrimp, octopus, and squid impacted the production of the porpoise’s milk. The two cetaceans selected for the study – the East Asian and Yangtze finless porpoises share similar breeding season and lactation stages, making it easy to compare their milk composition. Scientists collected samples from both live – captured porpoises and porpoises that were unintentionally caught in fishing nets.

Being able to draw milk from various individuals was beneficial in that scientists were able to observe the changes during the lactation period, as well as conclude why such changes occur. In any organism, the dietary demand is high in order to meet the necessary nutrient supply for optimal milk production. Milk production is vulnerable in many organisms, the smallest change can affect the quality of milk and can be detrimental to the young during nursing. It is well known that when nursing, the fat and other components are being consumed which helps create that thick layer of blubber, which is an insulating factor to keep the organism warm. Without it, many young will struggle to survive.

Scientists reported from their study that pregnant finless porpoises produced a greenish colored milk with high protein levels and barely any fat. While nursing mothers produced milk that was a white color, with high sugar levels and greater fat content. The better resources an expecting mother has, the better quality milk she produces and the more successful her offspring will be. Any factor can alter this however, a change in water quality, increase in predators or competition, decrease in food abundance, and so on. Gaining a better knowledge of milk production in cetaceans is beneficial in evaluating future issues that come up with marine survival.

For more information, check out the original scientific paper:

Zeng, X., Huang, S.-l., Qian, Z., Hao, Y., Wang, D., Ji, J. and Nabi, G. (2017), Characterization of milk composition in narrow-ridged finless porpoises (Neophocaena asiaeorientalis) at different lactation stages. Mar Mam Sci, 33: 803–816. doi:10.1111/mms.12398

Jinkies! Minkes Negatively Impacted by Sonar - By Emma Pontius

Sonar is a tool that is used by the United States and other countries’ Navy. It is a method that uses sound underwater to aid in detection, navigation, and communication. This study looked into sonar at 1–4 kilohertz, which may not seem substantial to humans but how does it impact marine mammals? This question was looked into further in the research conducted by Petter Kvadsheim et al in the paper: Avoidance responses of minke whales to 1–4 kHz naval sonar. The study conducted observed minke whales off of California and Norway.

Echolocation is a crucial function that marine mammals use for a variety of reasons. It is similar to sonar in that marine mammals use it for detection, navigation, and communication. With dissimilar sound waves there is bound to be some interference. Mass stranding events have been linked to cetaceans sensitivity to sound. A total of four whales were monitored in this study. Two minke whales were exposed to the naval sonar while two were not and were used as the “baseline” group.

Scientists observed all four of the whales behaviors by attaching monitors onto the whales. This is a method that has mixed reviews, with the possibility that the monitors could fall off and data would be lost. However, in this study they proved to have some success. The data that was collected looked into dive behavior, avoidance behavior, and potential energetic costs of disturbance.

The significant findings from this study were that whales in the eastern Pacific showed avoidance behaviors when exposed to the sonar. The whales speed increased from 1 meter per second to 5 meters per second when exposed and moved away from the sound source. The Atlantic whale showed an increase in energetic cost. In the Northeast Atlantic minke whales are still harvested and could be an indicator of their avoidance behavior associated with anthropogenic noise. There have not been many studies conducted looking into minke whales response to anthropogenic noise and while this experiment had its faults it is a good start to a new area of research.

For more information, check out the original scientific paper:

Kvadsheim, P.H., DeRuiter, S., Sivle, L.D., Goldbogen, J., Roland-Hansen, R., Miller, P.J., Lam, F.P.A., Calambokidis, J., Friedlaender, A., Visser, F. and Tyack, P.L., 2017. Avoidance responses of minke whales to 1–4kHz naval sonar. Marine Pollution Bulletin.

Return of the Porpoises - By Helen Reese

After vanishing from San Francisco Bay for over 60 years, harbor porpoises have finally returned. Harbor porpoises are one of the smallest species of toothed whale at 5 to 6.5 ft. long and 110 to 155 lbs. fully grown. They inhabit cool coastal waters and are found along the central and northern California coast.

In a recent study, S. Jonathan Stern and his colleagues spent 288 hours between 2011 and 2014 on the Golden Gate Bridge scanning the bay for the presence of harbor porpoises. They spotted a total of 2,698 groups of porpoises spanning 2 to 16 animals per group, supporting the idea that they use the San Francisco Bay on a daily basis year round. A higher number of calves sighted in the summer months suggests that the bay may be an important habitat for breeding activities.

According to skeletal remains, harbor porpoises occupied San Francisco Bay starting approximately 2,600 years ago. So why did they leave in the first place?

The long-term absence of porpoises in the area was likely due to the effects of human modifications to the bay. Disturbances first began in the mid-19th century with the start of the gold rush which brought with it hydraulic mining and mercury contamination of surrounding waters. This period of rapid population growth and urbanization led to pollution, alteration of wetlands, and major construction projects such as the Golden Gate Bridge.

In the 1940s, San Francisco Bay experienced a profound increase in vessel traffic, shipyard construction, and harbor fortification including hundreds of floating mines at its entrance. A World War II-era anti-submarine and anti-missile net was installed, stretching 3 miles across the bay from San Francisco to Sausalito. Porpoises would have been unable to pass through the rings that made up this net, physically barring them from parts of the bay. Harbor porpoises are also very sensitive to noise. Researchers suggest that the net could have discouraged them from entering the general area due to the “sounds generated by the metal mesh… as well as by return signals from the porpoises’ echolocation clicks.”

Furthermore, the water quality of the bay declined over the course of the 20th century, producing unfavorable conditions for its biological communities. This could have possibly reduced the amount of food available for the porpoises, effectively driving them to other areas to feed.

While Stern and his colleagues are not completely sure why the porpoises have returned, they acknowledge the grassroots efforts of citizen groups in the 1960s to reduce municipal and industrial pollution. These efforts led to drastically improved water conditions in the bay by the 1990s, at which point habitat restoration projects were well underway. Now the bay is considered relatively healthy with stable fish populations and increased productivity, setting the stage for the return of the porpoise.

For more information, check out the original scientific paper:

Stern, S.J., Keener, W., Szczepaniak, I.D., Webber, M.A. “Return of harbor porpoises (Phocoena phocoena) to San Francisco Bay” Aquatic Mammals vol. 43, no. 6, 2017, pp. 691-702.

Creating Acoustics to Protect the Endangered Finless Porpoises - By Peter Roy

December 3, 2017

Omara Bay, Japan – Finless porpoise populations have been declining off the coastal waters of southwestern Japan to the point of endangerment. This particular marine mammal species is unique in that they lack a dorsal fin along their backsides. A strong influence on the declining population numbers is a result of anthropogenic, or human-based influences such as by-catch, which is the unintended catch when fishing for desired commercial marine species.

Research scientists, led by Masao Amano, from Nagasaki University conducted a long-term study that tested the effectiveness of sound-producing acoustic pingers in warming finless porpoises to avoid the sounds produced along designated gillnets.

Acoustic pingers are an alternative method to prevent the interaction of finless porpoises with fishing gear in the water, such as gillnets. Gillnets are nets that stretch out horizontally along the sea floor at shallow coastal depths and are left to soak in the water. The mesh size on the net is sized to capture a target commercial fish by catching a fish’s head. The flaring structure of fish gills prevent the fish from escaping. Gillnets pose threats to marine mammals, such as finless porpoises, who spend their time in shallow coastal waters. As the net is left to soak, it can increase the opportunity for an unsuspecting porpoise to become entangled in the net. Increased opportunities for entanglement also arise with an increase in fishing efforts to keep up with human seafood demands. If the porpoise fails to escape, then the individual will drown, as porpoises are air-breathing mammals.

The researchers conducted the experiment over two eight-month periods to compare the rate of encounters of finless porpoises in Omara Bay. For four months, the pingers were actively creating sound, and then there was no use of pingers for four months. The process was repeated the following year.

The results informed the researchers that the acoustic pingers were initially effective in establishing avoidance between the finless porpoise and noted gillnets, however, that effectiveness dwindled over time as more encounters were observed. This allowed the researchers to understand that the species may have become familiar with the sonar as researchers observed a greater number of finless porpoises in the area of the study.

As an alternative the researchers proposed alternating the active periods to increase the effectiveness of acoustic pingers with respect to avoidance. Doing so would give the researchers hope that finless porpoise encounters would decline and promote population growth.

This issue of marine mammal by-catch as a result of entanglement in in fishing nets does not just impact finless porpoises. Vaquitas are another porpoise species that are on the verge of extinction due to sharing a habitat that overlap with commercial fishing in the northern Gulf of California. By better understanding of how acoustic pingers impact these species, effective measures for avoidance can be better enforced to cut back on marine mammal entanglement encounters. By doing so, we can hope for rebounding populations of our beloved porpoise friends.

For more information, check out the original scientific paper:

Amano, Masao, Kusumoto, M., Abe, M., Akamatsu, T. 2017. Long-term effectiveness of pingers on a small population of finless porpoises in Japan. Endangered Species Research. 32. 35-40. Accessed: http://naosite.lb.nagasaki-u.ac.jp/dspace/bitstream/10069/37428/1/ESR32_35.pdf

From Garbage Disposals to Picky Eaters: Why Sea Otters Choose Their Food - By Carolyn Ryan

Cute and cuddly, sea otters are among the smallest members of the marine mammals. When these charming animals spend time in the water, the majority of their time is spent diving to the seafloor to forage for food.

Sea otters could be considered garbage disposals of the sea. They will eat just about anything – ranging from sea urchins and sea stars to shellfish and crabs, as well as many things in between. Early studies of sea otters from the renowned marine ecologist Jim Estes had shown that individual sea otters tend to be picky eaters, choosing to eat only one or two types of prey. While mothers and daughters tend to have a similar diet, different families in the area have their own unique tastes.

This raises the question as to why this diet specialization exists: is it because of competition or a result of environmental factors? Kristin Campbell and Sharlene Santana wondered if it was something more, and asked if specialization in food choice was based on skull shape and tooth design. Are sea otters limited in what they can eat because of the shape of their faces and mouths?

To answer this question, researchers reviewed photographs and measurements of skulls from both male and female sea otters from both the northern and southern subspecies. The northern subspecies is found from from Alaska to Oregon, while the southern subspecies is found around the coast of California.

The researchers found that there was no difference in the bite force between males and females, but they did find differences in the shape of skulls between between males and females as well as between the northern and southern subspecies. However these differences were very subtle and were determined to not affect diet choice.

Instead, Campbell and Santana offer a suggestion that diets could be based on the conditions the animal is living in. If food is readily available and there is little competition, the sea otters may choose to be more general feeders, acting as free swimming garbage disposals. However if there is less food available and many other sea otters are in the area, then they may narrow their diets. Their ability to outcompete other sea otters may rely on things such as on tool use, maturity, or advanced foraging skills.

Rather than sea otters acting as garbage disposals when food is scarce and being more picky when food is abundant, this would imply that the opposite is true – as food becomes less available, sea otters become more picky.

For more information, check out the original scientific paper:

Campbell, K.M., and Santana, S.E. 2017. Do differences in skull morphology and bite performance explain dietary preferences in sea otters? Journal of Mammalogy. 98(5):1408–1416

What’s the Skinny? Polar Bear Attacks are on the Rise - By MaryBeth Semosky

A global study done on polar bears has shown that the decrease in polar ice cover due to climate change has been tied to increases in aggressive human-bear interactions.

Lead author of this research, James Wilder with the Marine Mammals Management sector of the U.S. Fish and Wildlife Service in Alaska, believes that polar bears get a bad rap.

“There isn’t a lot of incentive for them to be aggressive — unless times are bad. That seems to flip a switch. They seem to turn into a different beast.”

These bad times Wilder speaks of are times of reduced ice cover that are extending in recent years. Believed to be due to climate change, the decline of arctic sea ice has influenced polar bears to search for food on land – and closer to human communities.

Polar bears, top predators of the Arctic food chain, rely almost entirely on the ocean for food. Their diet is primarily made up of seals, and they are extremely dependent on the ice for shelter and resting from hunting.

Of the polar bear attacks on humans resulting in injury alone, 61% of the bears were categorized as having a body condition of below-average. In fatal attacks, 65% of bears were also considered as below-average in body condition. By far, the vast majority of the 73 reported polar bear attacks, both fatal and non-fatal, had a probable cause of predation on humans.

Because the bears reaching Arctic communities that border the sea are oftentimes underweight and searching for prey, it brings up the serious implications of human-wildlife interactions. Former deputy director of Russia’s Arctic National Park, Maria Gavrilo, seems to agree.

“Since bears are more hungry, and they’re actively looking, they smell food, and … they come up to human dwellings, and that leads to conflicts with people” Gavrilo stated in response to recent polar bear attacks in Northern Russia.

Wilder’s study did detail some effective tactics to surviving and avoiding potentially harmful polar bear interactions.

More than half of the 63 injury-only attacks had intervention by witnesses that ultimately saved the victims, therefore power in numbers may discourage bears from predating on humans.

In the 16 incidents where those involved had bear spray, none of them resulted in either party being injured or killed. Bear spray is also extremely effective with other species of bear, though in many countries this deterrent is illegal.

Many, if not all, of the interactions studied in this research also had wildlife attractants involved, including readily available trash bins, animal food, and hunting equipment/meat left outdoors. These items can draw a starving polar bear into a residential area.

For more information, check out the original scientific paper:

Wilder, J. M., Vongraven, D., Atwood, T., Hansen, B., Jessen, A., Kochnev, A., York, G., Vallender, R., Hedman, D. and Gibbons, M. (2017), Polar bear attacks on humans: Implications of a changing climate. Wildl. Soc. Bull., 41: 537–547. doi:10.1002/wsb.783

Hawaiian monk seals are making a comeback in the main Hawaiian Islands, but why not everywhere else? - By Allie Simoes

Seals are everyone’s favorite water puppies. Belonging to the group pinnipeds, there are around 18 or 19 species of true seals, or phocids, the ones that lack visible ear flaps.

Hawaii is home to one of the rarest marine mammals (according to NOAA), none other than the adorable Hawaiian monk seal. Hawaiian monk seals are one of the more endangered marine mammals whose numbers are still declining. The main Hawaiian Islands (MHI) and the northwest Hawaiian Islands (NWHI) show differences in population sizes in these seals, possibly due to differences in food available, or in habitat quality.

To find out what is causing these differences in population size between the islands, scientists Kenady Wilson and Andrew Read from Duke University’s Marine Lab, and Charles Littnan from the NOAA Fisheries department set out on a mission to study Hawaiian monk seals’ dives and foraging behaviors to better answer the question: why are the seals of the MHI spots more successfully recovering than seals in the NWHI?

Wilson and her team caught adult seals of both genders and sedated the seals to allow the team to glue GPS tags to the animals’ back. The team excluded pregnant seals, pups, wounded or molting seals, and not capturing during hot days to reduce stress. These tags would record location every 20 minutes unless the seal was underwater. A total of 29 seals were tagged and data from 19 of these seals was recovered.

According to their data, most of the seals (63%) stayed around the islands they were tagged on while the others (37%) bounced around to neighboring islands. It was also found that most of the seals’ dives were short and in shallow waters but when the seals had to forage, the dives were longer and deeper towards the sea floor. Over all, seals spent about half of their time diving, and the other half split between being at the surface and being out on land. To answer the original question, because the seals at the MHI do shorter trips to find food, their survival is higher than the NWHI seals who are out at sea longer. This lower amount of time at sea also suggest that foraging is easier and may imply that food is in higher abundance around the MHI, increasing habitat quality and survival.

For more information, check out the original scientific paper:

Wilson, K., Littnan, C., & Read, A. J. (2017). Movements and home ranges of monk seals in the main Hawaiian Islands. Marine Mammal Science,33(4), 1080-1096. doi:10.1111/mms.12429

Monk Seals Find a New Hawaiian Get Away - By Gretchen Spencer

How do you try and save a species that spends most of its time diving deep at sea? Or a species that is native to one island but is slowly moving to others for unknown reasons? These are more than true scenarios for the endangered Hawaiian monk seals, which in recent years have been calculated to have as few as 1,000 individuals left in their population.

Most monk seals are located in the northwestern Hawaiian Islands; However, a small proportion of the population has been settling on the main Hawaiian Islands in recent years. Scientists are baffled as to why this habitat shift is occurring, as the main island has potential for more human interactions that could affect the seals survival overall. Scientist Kenady Wilson and her colleagues have set out to find the reason for these shifts in habitats, to better understand how to manage the seal population in the future.

Wilson and others set tagged twenty-nine adult monk seals between 2010 and 2014 using various recording instruments that could determine if the seals were on land or at sea, or if they were diving or floating at the surface. These devices could also give immediate GPS locations, so once the data was recorded, the scientists created maps of where the monk seals spent most of their time and how far out in the ocean they swam, potentially looking for food sources.

From their findings, over half of the monk seals spent all their on-land time on one island, while some seals traveled to the nearby islands and back. There were some extreme cases of seals that spent days traveling at sea, to islands not even remotely close to their home bases. However, monk seals generally remained at sea for a day, traveling and diving for food. These food voyages also varied in distance from the monk seals home beach, but many of the seals stayed relatively close to their beach front and only cruised the shoreline in search of their dinner, which lay hidden on the bottom on the ocean floor.

Wilson’s study showed that monk seals are complex, roving creatures. Although the seals do prefer a home base, they are fully capable of touring the surrounding islands in search of food and to avoid predators. Wilson’s work also provided information that showed the monk seals who have begun to inhabit the main Hawaiian Island seem to have a more set schedule. These seals take shorter trips to sea and travel shorter distances than their counter population over in the northwestern islands.

Knowing the full scope of how fast and far monk seals travel will be important in upcoming years for policy makers; who want to preserve this ever-dwindling species. Hopefully Wilson’s work will help implementers find a balance between trying to shelter the monk seal population from harm while also understanding that these roaming creatures are bound to go their own ways.

For more information, check out the original scientific paper:

Wilson, K., Littnan, C., & Read, A. J. (2017). Movements and home ranges of monk seals in the main Hawaiian Islands. Marine Mammal Science, 33(4), 1080-1096. doi:10.1111/mms.12429

Marine Mammals Die from Seafood Poisoning - By Lacey Wetzel

After a heavy rain on the St. Lawrence Estuary in Quebec, Canada, several marine mammals were found dead. These included 10 beluga whales, 7 harbor porpoises, a juvenile fin whale, and 85 seals. Of the seals reported, 14 adult females were determined to be pregnant when the animal was examined after death.

During the animal autopsy, Starr et. al. determined the cause of death for these animals was seafood poisoning. PST is very hard to diagnose, so their conclusion was based off of symptoms and the eliminate of all other causes of death. The toxin responsible for poisoning these animals was paralytic shellfish toxins, PST, most commonly found in oysters and clams, as well as other similar organisms. These shelled organisms are tolerant of these toxins that pose a health risk to others. Common effects of PST, to those who are susceptible, are the paralysis of the lungs, tingling, numbness, drowsiness, fever, rash, etc. Respiratory arrest can occur within 24 hours if enough of the toxin is ingested, condemning the animal to death.

The toxin was found in the liver, stomach, and intestines of the animals reported dead. While they found that 96% of the animals examined were in good nutritional health, with bellies full of fish and other normal dietary substances. They also discovered signs of “wet, heavy, and congested lungs,” expected to be paralysis of the lungs, common with PST (Starr et. al. 2017). Additionally, there was congestion of the throat and mouth, sometimes paired with blood from irritation and insufficient movement coordination.

It is suspected that the high levels of the toxins were brought on by an increase of the algae known as Alexandrium, which makes this toxin. The large increase of the algae, known as a bloom, was most likely brought on by the heavy rain that had occurred. There are 3 ingredients needed to form these algae blooms, warm temperature, excess nutrients, and a slow-moving water source. With the first two ingredients already fulfilled the heavy rain would have provided the last.

By these mammals eating the animals that eat the toxic algae, the concentration of the toxin built up in the mammals’ system until it became fatal.

For more information, check out the original scientific paper:

Starr, M., Lair, S., Michaud, S., Scarratt, M., Quilliam, M., Lefaivre, D., & … Measures, L. (4 May 2017). Multispecies mass mortality of marine fauna linked to a toxic dinoflagellate bloom. Plos ONE, 12(5), 1-18. doi:10.1371/journal.pone.0176299

So What Exactly IS Climate Change, and Should I be Worried? - By Genevieve Wilson

With only 12 species of marine mammals that regularly inhabit the arctic, can we really afford to lose one or two species to extinction? The answer is no. Without the appropriate care for our ocean and life that inhabits it, the human race will suffer just as much; struggling to find food, shelter, and comfort due to just a small temperature shift. A recent study done by Kristin Laidre, a marine biologist from the University of Washington working on problems of applied animal ecology, assess the potential behavior of arctic marine mammals when forced to deal with habitat change.

Imagine you live in a nice warm climate down south near the equator, and then all of a sudden the weather changes so drastically that it now snows in your area. This is similar to what it feels like to have your habitat shifted beyond your control, but imagine that this shift seriously affected your lifestyle, including your ability to raise your children or find food. NOAA has reported a 0.8°C temperature increase since 1880 (NOAA, 2010). Although it may not seem like a lot, just one degree of an increase in temperature could be damaging to both terrestrial and aquatic life. Don’t forget that a little less than a 5 degree drop put most of North America into an ice age thousands of years ago. Shifts in climate all around the world are having an impact on almost all species of this Earth, but here we focus on the arctic.

Kristin Laidre did a study on the effects of habitat change on seven arctic and four subarctic species. Will these species survive after being forced to move against their will? Researchers say that we may never know until it happens, but predictions have been made. The researchers of this study reviewed species behavior, population size, habitat requirements, and evidence for biological and ecological responses to shifts in climate. Then, they created a quantitative guide of species sensitivity to climate change based on distribution, feeding specializations, seasonal dependence on ice, and reliance on sea ice for survival.

Laidre’s results state that the hooded seal, the polar bear, and the narwhal appear to be the three most sensitive arctic marine mammal species, primarily due to reliance on sea ice and particular feeding. The least sensitive species were the ringed seal and bearded seal, primarily due to large circumpolar distribution, large population sizes and flexible habitat requirements.

The good news is, some of these effects are driven by human activity, and can be reduced with enough opposition, such as writing to your local mayor or governor. Two human activities in the arctic that affect these marine mammals are hunting and pollution. This pollution can include noise, trash, plastic, or anything else that enters the ocean because of human activity. It is not likely that alterations will be made to hunting restrictions, which is why this needs more attention brought to it.

For more information, check out the original scientific paper:

Laidre, K. L., Stirling, I., Lowry, L. F., Wiig, Ø, Heide-Jørgensen, M. P., & Ferguson, S. H. (2008). Quantifying The Sensitivity Of Arctic Marine Mammals To Climate-Induced Habitat Change. Ecological Applications, 18(Sp2). doi:10.1890/06-0546.1