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.


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

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.

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:

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