Lab News

Aug 07
0

Our new eDNA lab is up and running!

By | Research

This past week, Dr. Kristina Cammen and undergraduate research assistant, Liz Piotrowski, collected their first eDNA water samples at the Marine Mammals of Maine (MMoME) triage facility located in Harpswell, Maine. Thank you to Dominique Walk, MMoME’s assistant stranding coordinator, and several MMoME interns for their collaboration in this effort.

eDNA, short for environmental DNA, is free floating DNA that is left behind by an organism as it travels through an environment. We are working to develop protocols that will allow us to isolate and characterize this DNA, for example from a water sample collected in a seal rehab pool and ultimately from seawater samples collected near seal haul-out sites. Our hope is that these non-invasive sampling methods will enable future investigations of the genetic diversity and population structure of seals in the Gulf of Maine.

9/29/18: Updated to add that our first attempts to detect and sequence seal DNA from the MMoME facility have been successful!  We are now working to optimize our protocols so that we can distinguish between individuals that are present in the same pool of water.

Jul 02
0

Welcome, Alayna Hawkins!

By | Student News

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.

Jun 05
0

New publication – Genomic signatures of population bottleneck and recovery in Northwest Atlantic pinnipeds

By | Publication

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.