A two-person research team in Anacortes is collecting data about harbor porpoises seen off of some of the city’s shores, to document their migration patterns and the health of their habitat.
Some days, seeing harbor porpoises from the shore requires a watchful eye, while other days dozens can be seen in the shimmering water.
Cindy Elliser and Kat MacIver of the nonprofit Pacific Mammal Research in Anacortes spend two or three days a week on the brown cliffs above Burrows Pass watching for porpoises.
“There’s a porpoise in B4, he’s just cruising through that rip line,” MacIver said Wednesday while jotting down notes on a data sheet.
Elliser, from her position on the cliffs next to MacIver, moved her gaze and camera to look in the direction of “B4,” an area based on a grid system the two had outlined for their research. The camera clicked as she captured images of the porpoise.
Elliser took on the mission of documenting porpoises in the area in 2014 and founded Pacific Mammal Research in October of that year.
Her goal was to identify individual porpoises by looking at photographs of the spots and scars along their sides.
Today she can recognize 53 individual porpoises. About one-third of those have been seen multiple times during the research.
The idea is that recognizing porpoises can give Elliser clues as to how many traverse Burrows Pass between Anacortes’ Washington Park and Burrows Island, how often they are there and whether they are traveling in the same groups.
“Since we don’t know a lot about them, just recording what we see and other environmental factors can help us learn answers to questions you might ask, such as when do they mate?” Elliser said.
Anna Hall of the Porpoise Conservation Society in British Columbia said she plans to use Elliser’s photo identification method on porpoises along the shores of Vancouver, British Columbia, and potentially in Scotland.
“We hope to eventually be able to work throughout the range of harbor porpoise … We’re starting local and our goal is to go global,” Hall said.
She said she hopes the work will answer questions such as whether harbor porpoises move between the waters off of Washington and British Columbia or if they stay in smaller areas.
“Harbor porpoises are found around the world, so now that we know you can do photo identification on them, more people in more places can do it,” MacIver said.
So far she and Elliser have determined that the porpoises in Burrows Bay are most abundant during fall, are more likely to be seen when the current is slow, and calves are most commonly seen during the fall and when the tide is not moving.
While harbor porpoises are not threatened or endangered, understanding them is important because they are a top predator and what is called an indicator species, meaning the health of the harbor porpoise population can reflect the health of its habitat and that of other wildlife.
Elliser and MacIver do their research above Burrows Pass year-round.
During the past year, they have also used a hydrophone – a type of microphone that captures sound underwater – to get an idea of what sounds the porpoises are exposed to.
That information can help determine whether their behavior changes in response to an increase in noise, such as when there is more boat traffic during summer.
“Do we see them more or less often with different noise levels? Does sound influence why we see more of them in the fall than in the summer?” Elliser said.
She and MacIver said questions remain about the porpoises, including about their lifespan in the wild and where they go when they’re not in Burrows Pass.
“Porpoises do come back to this area, they mate here, they bring their calves here and they forage here, so this could be a very biologically significant area for them,” Elliser said of Burrows Pass.