Advancing Science, One Seal at a Time

Posted on February 16, 2023
SSC Marine Mammal Director Ashley Stokes standing in front of lighthouse on Monomoy Island.
SSC Marine Mammal Director Ashley Stokes

Ashley Stokes | Director, SSC Marine Mammal Rescue

Picture this: Staying in a historic lighthouse keeper’s quarters, on an uninhabited island for nearly a week, alongside 7 other biologist colleagues. Sounds beautiful, right? Now add in the details that it’s the middle of winter, freezing temperatures, gale force winds, no running water, no heat, no electricity, and sleeping on cots. To most people that may not sound appealing at all, but it’s something that I look forward to every year; all in the name of Science! Having not been able to join the trip since pre-covid due to tight federal regulations, I was so excited to be invited back out to Monomoy National Wildlife Refuge (an island off Chatham, Massachusetts) at the end of January, for the annual gray seal sampling trip led by Tufts University’s Runstadler Laboratory. Mother Nature was determined to keep us on the mainland, but we were able to find a small window to be able to get ourselves and our gear out to the island.

The targets: gray seal pups newly weaned from mom.

The mission: health and disease surveillance sampling.

Male and female gray seal on a beach with their young pupOnce on the island, the real work starts. Not only did we have to move our own personal gear from the beach to the lighthouse, we also had to take multiple trips (about .6 mile each way) to trek all of the sampling gear, lab gear, food, water, and propane; now that’s a workout in itself, and the real work hadn’t even begun yet! The days on the island are long and exhausting; often beginning just after sunrise and continuing until ~10pm at night. Lunch is eaten while out in the field between sampling animals, and dinner is prepared while simultaneously processing samples from the day’s animals in the other room, which acts as a makeshift lab. But, it’s what has to be done to fit in as much work in the ~5 days on island as we can!

Several women in cold weather gear surround a seal pup to conduct tissue and fluid samplingAfter conducting some reconnaissance on the island each morning to figure out a good sampling spot with multiple seal candidates, we gather our gear and make the move … being very careful not to disturb mother/pup pairs or the larger herds of seals resting on the beach. For each animal, the process includes: set up supplies, capture the seal, weigh the seal, collect data measurements, collect samples (blood samples, swab samples, lanugo fur sample, fecal sample, skin biopsy), subsample the blood collected, apply flipper tags, apply paint stick for easy re-identification throughout the week, release the seal, and then start all over again. The whole process, from setup to release, takes about 20-30 minutes for each animal.

Gray and white gray seal pup rests on dried grassAll in all, between the weather and gear schlepping to and from the boats, we were able to sample for 3 full days which yielded 31 animals sampled! My Apple watch also tells me that we traversed over 25 miles while on the island! Now the work continues in the lab, to process each of the samples collected from each animal. Some of the different things being researched and analyzed for, include: influenza, phocine distemper virus, phocine herpes virus, SARS-cov-2, contaminants (PCBs, mercury), habitat use, and overall baseline data for the health of the rookery over time. Then, the gear is inventoried and restocked … while we anxiously await next year’s trip!


All photos were taken by Milton Levin while following federal guidelines, using a telephoto lens when necessary, under NMFS permit #21719-01 and USFWS permit #53514-20-1.

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Seacoast Science Center will be CLOSED today: Friday, April 5, 2024. Our utilities are currently down and need to get repaired before we are able to open for visitors. Thank you for your understanding. 

CLOSED today.

Seacoast Science Center is closed today due to inclement weather.