The Cammen Lab welcomes their newest member, Alayna Hawkins, who begins an MS in Marine Biology program this summer. A recent graduate of St. Francis College in Pennsylvania, with an interest in marine mammal science and genetics, Alayna joins the lab to conduct research on gray and harbor seal immunogenetics. She hopes to help elucidate why gray seals appear more resistant than harbor seals to several viral diseases through an exploration of the genetic diversity of their immune systems.
The recent recovery of gray and harbor seals in the Northwest Atlantic, following historical exploitation and subsequent protection, provides a natural “experiment” in which to evaluate the impact of changes in population size and distribution on genetic diversity. It is a rare opportunity to test evolutionary theories, for example that genetic bottlenecks will reduce diversity (in extreme cases, leading to inbred populations), in a natural population. With a genomic approach, called RAD sequencing, we evaluated how diversity has changed over time and space in multiple cohorts of gray and harbor seals sampled over the past half-century. Our findings clearly show that signatures of historical bottleneck remain in the genomes of the species today, but also find high contemporary diversity, suggesting the species are not inbred. Interestingly, we find higher diversity in gray seals than harbor seals, which may have important implications for species fitness, a point we’d like to continue to investigate moving forward.
Co-authors on this paper include collaborators from the Duke University Marine Lab, NOAA NEFSC, Canada DFO, Tufts University, and St. Mary’s University. If you’re interested in other research we’ve done on this topic, check out our comparison of contemporary and archaeological seals from this region.
A full, freely available copy of our new open-source paper can be found here, or feel free to contact me directly for more information.
Cammen KM, Bowen WD, Hammill MO, Puryear WB, Runstadler J, Wenzel FW, Wood SA, Frasier TR, Kinnison M (accepted) Genomic signatures of population bottleneck, recovery, and expansion in Northwest Atlantic pinnipeds. Ecology and Evolution.
Liz Piotrowski scans for marine mammals in Western Passage using BigEyes.
This summer, undergraduate research assistants, Emma Newcomb and Liz Piotrowski, are leading a shore-based marine mammal visual monitoring program in Western Passage, a promising site for future tidal energy power. Once a week, they travel to Eastport, ME to conduct a 4-hour visual observation period, which later this summer will be supplemented by passive acoustic monitoring for marine mammal vocalizations (led by Chris Tremblay in Gayle Zydlewski’s lab). In their first month of observations, Emma and Liz have observed harbor porpoise, harbor seal, and minke whale.
Emma Newcomb looks out over Western Passage in search of marine mammals.
This research is conducted in collaboration with Ocean Renewal Power Company. Emma’s summer internship, which also includes a historical analysis of marine mammal stranding rates in Maine, is funded by the SEA Fellows program.
