BAR HARBOR — On a recent sunny morning in late October, before fall winds swept the rest of the leaves from the trees, several students at College of the Atlantic gathered on the lawn of the college for an unusual task: the necropsy of an Atlantic white-sided dolphin (Lagenorhynchus acutus) that was brought ashore in Deer Isle. Metal tables were sanitized and set, blue gowns and long gloves were donned, and students set about their work.
“I’ve always been extremely squeamish,” said Reese Armstrong, a first–year student at COA who photographed the process. “Really, the worst thing was the smell and that was tolerable. There was a lot of blood, there was a lot of guts,” he acknowledged, but “It really wasn’t bad.”
“I would consider myself generally pretty sensitive,” said graduate student Elle Gilchrist. “I have a really hard time doing necropsies. There’s that first cut where you cut into the body …You’re watching this blood pour and that’s the moment I have to turn off my human brain and I have to turn on my scientist brain. You really need to turn off your emotional capacity and just start thinking analytically.”
Scientists who study marine mammals, Gilchrist added, don’t have many opportunities to learn about animal physiology firsthand. “Tactile learning with marine mammals is really difficult. You can’t go walk up to a seal and pick it up. We don’t have the same opportunity vets do.”
This dolphin had been spotted alive, moving around in Pickering Cove on Deer Isle, by local kayakers, said Rosemary Seton, marine mammal stranding coordinator at Allied Whale, the marine mammal laboratory at COA. They later found it passed away and helped bring it to shore.
There are many dolphin species in the Gulf of Maine, said Seton, but the Atlantic white-sided is the most common. “Beautifully marked,” with a graceful white stripe and weighing between 400 and 500 pounds once full grown, “they’re really kind of striking dolphins,” said Seton.
Despite dense populations of the animals around the shores of Newfoundland and Cape Cod, “It’s very rare that we get a dolphin or a porpoise,” said Gilchrist, which presents a unique opportunity for students and staff to study the animal, trying to determine how and why it may have separated from its pod, whether it was injured or sick.
In this case, the dolphin had no visible injuries, said Gilchrist, but, “When we opened the stomach up there was hardly anything in it. There were pretty much only squid beaks. She hadn’t eaten in a while.”
That isn’t necessarily the cause of death, Gilchrist added, but the dolphin was “slightly too skinny,” with a thinner blubber layer than might be expected. “It’s hard [to tell a cause of death] unless it’s very obvious.”
Working for roughly seven hours, the students examined organs, took “tons of measurements” and many samples, some of which will be given to COA graduate student Rachel Rice, who is studying whether certain pollutants accumulate in marine mammals. (“Spoiler alert,” said Gilchrist. “They do.”)
Although mass strandings of marine mammals are more common in Cape Cod, where animals may come into the bay chasing food and get trapped when the tide goes out, they’re rare in Maine, said Seton. “If it is a dolphin on its own, inshore, it’s kind of a red flag that something’s wrong. It’s sick, injured.”
Once the examination is finished, the remains of the dolphin will be composted or given to Dan DenDanto, a research associate with the college, who will bury it, wait for it to decompose and then work with students to articulate the skeleton.
“We’re looking to gain experience,” said Gilchrist. “How can we respond, what can we learn from this dolphin? It becomes this experiential learning process.”