On January 4, fishermen in Bremen, Maine, alerted the state’s Department of Marine Resources that a 26-foot-long male basking shark had washed up on the shore of Greenland Cove.
People aren’t yet sure how the shark, which is about the length of two small cars parked end-to-end, perished. But scientists with the Maine Department of Marine Resources gathered tissue samples to find out its cause of death, as well as study its aging, diet and genetics, Gabrielle Mannino reports for News Center Maine.
Basking sharks are the second-largest fish species on Earth, behind whale sharks. While whale sharks tend to live in warm, tropical waters, basking sharks live in arctic and temperate waters relatively close to land, according to the Florida Museum of Natural History, which makes them the largest fish found near New England and in the North Atlantic.
The little-studied species earned their common name because they seem to be basking in the sunlight, as they are typically seen swimming near the surface or in shallow waters.
Like whale sharks, basking sharks are filter feeders. (Only one other shark species, the megamouth shark, feeds the same way.) That means that while adults can reach an imposing 28 feet long, basking sharks are gentle giants. The sharks feed on small plankton, fish eggs and fish larvae by keeping their three-foot-wide mouths open while swimming through patches of the critters, per the New England Basking Shark and Ocean Sunfish Project.
When a basking shark swims near the surface of the water, its dorsal fin sometimes sticks up above sea level, so they’re often mistaken for a more notorious predator.
“[Basking sharks] come here every year to feed on very specific types of crustaceans and copepods,” said Arizona State University shark expert James Sulikowski to Bangor Daily News’ Aislinn Sarnacki in August, after a shark attack at a Maine beach sparked concerns. “They’re filter feeders, so they just swim around with their mouths open, and sometimes they’ll come super close to shore. Nine out of ten times that’s what people see and think they’re white sharks, but they don’t really have teeth.”
According to the New England Basking Shark and Ocean Sunfish Project, basking sharks as big as 40 feet and 19 tons have been spotted in the region. However, the fish usually migrate to warmer waters in winter, making the Bremen shark even more unusual.
However, it’s not the first time that a basking shark has washed up on the coast of Maine. When one washed up onshore in October 2000, local news reported that it had probably died after colliding with a boat propeller. The gash on its nose disoriented it and may have become infected.
A similar event occurred last year, when a disoriented or ill basking shark became stranded on the Yorkshire coast, BBC News reported in August. Marine experts attempted to shepherd it out of the shallows and out to sea, but the shark returned, and ultimately it was euthanized by a veterinarian.
During the 20th century, basking sharks were so intensely hunted that they are now an endangered species, Jason Daley reported for Smithsonian in 2018. People used the sharks’ liver oil for lighting lamps, skin for leather and meat for food. But the sharks’ reproduction rate is very slow—the gestation period is at least three years.
The shark at Greenland Cove may provide a new research opportunity for marine scientists. DMR spokesperson Jeff Nichols tells News Center Maine that the department will work with the New England White Shark Research Consortium, which formed in December 2020, to analyze the shark’s remains.