Amy Knowlton pilots the 29-foot research vessel Nereid out of Lubec harbor and into the waters of the Bay of Fundy, off of easternmost Maine. A scientist with the New England Aquarium's Anderson Cabot Center for Ocean Life Knowlton points to harbor porpoises chasing fish in the wind-swept waters on a recent morning.
Then something much larger appears off the stern.
"Whale behind us," Knowlton says, steering closer. "It's probably a humpback or fin whale, we'll get a better look."
It turns out to be two humpback whales — a cool sighting, but not the kind she is after.
Knowlton is hoping to find the endangered North Atlantic right whales that she and her colleagues have been studying in these waters since 1980.
Right whales are large cetaceans, with big heads and no dorsal fins. Researchers used to count as many as 200 foraging here in late summer. But the whales became scarce starting in 2010, and their range shifted dramatically. Many more are now summering hundreds of miles north, off Canadian shores in the Gulf of Saint Lawrence. More than 130 have been spotted there in recent months.
Marianna Hagbloom, a research assistant on Knowlton's team, surveyed that area in August and said it was nothing like the Bay of Fundy.
"We had days where we were seeing about 50 individuals," Hagbloom says. "Just right whales popping up left and right. It's a beautiful thing to see."
Despite those sightings, the North Atlantic right whale is seriously endangered, with a total remaining population below 450.
Their numbers have been falling for a decade, as the whales get entangled in fishing gear or killed by ships. Seventeen died in 2017 alone. In September, the National Oceanic and Atmospheric Administration declared that there was "considerable urgency to address the issues of mortalities that stem from human activities."
Another factor is that reproduction has also declined; researchers found no new calves last winter.
With the population on edge, scientists are seeking to understand the reasons for the new migration pattern away from the Bay of Fundy.
"My hypothesis is that this change in the migration patterns of whales is connected to their food resource, mainly calanus," says researcher Nick Record, referring to the sort of fat-rich plankton the whales prefer. "Calanus is like the battery of the Gulf of Maine," he says.
Record, a computational ecologist with the Bigelow Laboratory for Ocean Sciences in East Boothbay, Maine, has been collaborating with the New England Aquarium whale team, and analyzing data on whale numbers, plankton distribution and water temperature.
He says a changing climate is not only rapidly warming the region's waters; it's also shifting the currents that once swept this important plankton into the deep basins where right whales feed, making it less available to them.
Moira Brown, a scientist with the New England Aquarium and the Canadian Whale Institute who has been studying right whales since the 1980s, says she actually finds hope in the habitat shift from the Bay of Fundy to the Gulf of St. Lawrence.
"It's not like it's right next door, whales have to swim all the way around Nova Scotia" to get there, Brown says.
"So what a tremendous response," she adds. "This is a highly endangered whale, there's not many of them left, and yet they are demonstrating that they can respond to major changes in their habitat, and that's actually quite encouraging."
Despite the animals' apparent adaptability, Brown is concerned by the drop-off in the waters near Maine.
"It's not that this area is abandoned, but geez, our count for this year is less than a dozen whales," she says.
Back at the dock in Lubec, Knowlton's crew ends their 30-mile survey, the last of the season, with no right whale sightings. But she says it's worth sticking with the research.
"We're in a whole new era right now, with climate change, with habitat shifts," the marine scientist says. "It's important with this long-term study to maintain some of the basic efforts that we've had so that we can better understand what's happening to the whales."
She says her team will be back in the Bay of Fundy next summer, gathering more data, even if the right whales are still few and far between.