Dead gannets washing up on the shore of southern Maine and Massachusetts have raised suspicions that a toxic algal bloom could be to blame.
Chris Dwyer, a wildlife biologist with the U.S. Fish & Wildlife Service, said Friday that approximately 100 northern gannets have been found dead in the region over the past couple of months, most of them on Cape Cod.
“It is unusual for gannets to be washing up in those numbers,” Dwyer said.
He added he expects that some dead gannets have not been found or reported, but “not a lot more” because their relatively large size and the infrequency of the birds on land make them stand out. One, he said, was found on a golf course.
According to WGME, three more northern gannets have been found dead in Maine, one of them on Parsons Beach in Kennebunk.
An article by the Cape Cod Times quotes Massachusetts wildlife rehabilitation officials as saying that the condition of the seabirds suggests that some sort of-quick-working toxin may be to blame. Toxins produced by ocean algal blooms have been known to kill marine mammals that have consumed affected fish, the paper reported. Necropsies on the dead birds so far have proven inconclusive, the paper added.
Scientists have said that warming ocean temperatures and pollution have contributed to harmful algal blooms that have been reported in recent years in Florida, on the West Coast and, to a lesser extent, in Maine. Scientists have said global climate change is causing the Gulf of Maine to warm up faster than 99 percent of the world’s oceans.
Dwyer said that there have been reports of an algal bloom off of Cape Cod, but that scientists haven’t confirmed that the birds died from biotoxin poisoning. He said test results from necropsies on the birds, many of which have been found on beaches at Cape Cod National Seashore, aren’t expected back for another two to three weeks.
According to the conservation group National Audubon Society, gannets are primarily a pelagic species, staying out to sea when not raising their young or in poor health. The birds’ population declined sharply in the 1800s as humans hunted them and collected their eggs, especially along Canada’s eastern coast, but protections implemented since then have helped the species recover.
There have been other reported die-offs in recent years of northern gannets. In February 2016, 26 dead gannets were reported to have been found in Ormond Beach, Florida, according to the Ormond Beach Observer.
In 2015, CBC reported that officials in the maritime provinces of Canada were looking into the cause of deaths of gannets in New Brunswick. Dead gannets are found and reported “every summer,” according to the report. Some die from getting entangled in fishing gear, others are shot, and some suffer impact injuries from high-speed dives into the ocean while feeding on fish.
The CBC report indicated that there was no evidence that biotoxins had caused any of the deaths, but the possibility did concern at least one scientist who said he had examined more than 200 dead gannets over a few years.
Aside from the possible influence of algal blooms, Audubon says climate change is suspected to be affecting the birds in other ways.
“First, a northern gannet was seen for the first time in the Pacific Ocean in 2013. Some speculate that disappearance of Arctic sea ice is responsible, and that the species may even attempt to colonize the northern Pacific,” the group has written on its website. “Second, Atlantic Puffins have recently been having trouble at breeding colonies at the southern edge of their range. Gannets and puffins have similar colony distributions further north and the gannet may yet face the similar difficulties.”