Researchers say the study is just the latest piece of evidence that warming ocean temperatures are allowing these blooms to stretch into Arctic ecosystems, threatening marine life and the communities who rely on the sea to survive.
“The waters are warming, the sea ice is melting, and we are getting more light in those waters,” said Kathi Lefebvre, NOAA Fisheries research scientist. “Those conditions, without a doubt, are more favorable for algal growth. With that comes harmful algae.”
The study, which analyzed more than 900 samples taken from stranded or harvested marine mammals in Alaska between 2004 and 2013, found algal toxins in all species sampled, including bowhead whales, fur seals and sea otters.
“We were surprised,” Lefebvre said. “We did not expect these toxins to be present in the food web in high enough levels to be detected in these predators.”
“There seems to be a potential risk for marine mammal health,” she added. “Then there’s also a seafood security risk, in that these communities rely on and depend on these animals for food.”
“I think that’s going to have a huge impact on the Native communities and coastal communities in Alaska,” said Bruce Wright, senior scientist for the Aleutian and Pribilof Island Association, the federally recognized tribal organization of Alaska’s indigenous Aleut citizens. “I think that we’re going to see a number of shifts in our ecosystem as a consequence of warming, and I think some species will be displaced by other species, and others will disappear. There [are] going to be consequences and people are going to have to adapt.”
NOAA’s new study, released last week, comes after months of strange marine life die offs in Alaska. Last year, NOAA declared the deaths of more than 30 whales in the Gulf of Alaska to be an unusual mortality event. Just last month, thousands of dead birds began washing ashore in Prince William Sound.
“I’m pretty sure that’s associated with these algal blooms,” Wright said of the bird die offs and other events. Toxic algal blooms in the region, particularly 2015’s, likely wipe out entire parts of the lower food chain, he added, the effects of which reverberate through the ecosystem.
A massive toxic algal bloom, believed the largest ever recorded, reaped havoc in the Pacific in 2015. Stretching from southern California north to the Aleutian Islands and Bering Sea, it prompted the closure of recreational and commercial fisheries across the American and Canadian coastlines.
“It really does point out that there is a need for more monitoring,” Lefebvre said.
Increasingly warm waters in the north Pacific are believed to be behind other strange disease outbreaks as well. A recent study from the University of Puget Sound found that warmer waters in 2014 contributed to an epidemic of sea star wasting disease in the North Pacific, which decimated starfish populations in the north Pacific.
“My thought is, absolutely, the environment is changing very rapidly in Alaska,” Lefebvre said. “And it’s warming, and there are changes in fundamental parts of the ecosystem.”
She added: “And these ecosystems have developed over millions of years, so when they’re rapidly changing, the chances they’re going to be changed for the better, over all, are very slim.”
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