Climate change is impacting bowhead whales and the Arctic food web, and it stinks — literally.
New research from the Woods Hole Oceanographic Institution (WHOI) looked at the fecal matter of bowhead whales and found something alarming. Within the fecal samples were higher concentrations of algal toxins, indicating a major threat to the Arctic food web.
These toxins are not only a threat to the marine organisms that live in this region, but also the coastal communities in Alaska that rely on them.
Drifting Toxic Algal Colonies
The new study, published in Nature, analyzes the risks these toxins pose to animals like clams, fish, and even whales, which some Alaska Native communities harvest for subsistence purposes.
“These are new risks that were previously unknown,” said Kathi Lefebvre, a research scientist at NOAA Fisheries’ Northwest Fisheries Science Center in Seattle and lead author of the new study, in a press release. “The people in remote communities in northern and western Alaska rely on marine resources for nutritional and cultural well-being. Now we’re finding that these resources are at risk.”
During the study, the research team found that the Alaskan Arctic seabed has the largest concentration of Alexandrium cysts — dormant, toxic algae cells. The cysts form from toxic algae blooms in the Bering Sea, then drift north towards the cooler waters. Historically, the frigid waters stopped germination, but that has changed as water temperatures rise.
“For years, these cysts have remained inactive, essentially preserved by the cold,” explained WHOI senior scientist Don Anderson in the press release. “But as bottom water temperatures periodically warm, we see conditions that allow germination, and that changes the risk landscape dramatically.”
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Testing Whale Poo
For nearly 20 years, the research team has been testing bowhead whale samples from the Alaskan Arctic region. Because the whales eat krill that contain the toxin, the team knew testing the whales’ fecal samples would garner some of the best results.
“Nobody had a data set like this,” Lefebvre said in the press release. “Instead of going out every year and collecting samples across the marine environment, the whales did it for us. Their samples give us a snapshot of what is in the food web every year, as sampled by the whales.”
The team tested samples from 205 bowhead whales between 2004 and 2022 and tracked concentrations of domoic acid, which is produced by the marine algae Pseudo-nitzschia, and also looked for saxitoxin, which is produced by Alexandrium.
The results showed that 50 to 100 percent of the whale samples contained saxitoxin over a 19-year period. However, domoic acid was not as prevalent in the samples, and some years the research team didn’t detect any, but that is shifting.
Shifting Temperatures and Rising Toxins
According to the press release, Anderson has shifted his research focus to Alaskan waters, as it has become a hotbed for harmful algal bloom (HAB) research.
“It is a new frontier in HAB research given the rapid warming of waters in the region and the massive scale of the Alexandrium populations we have documented,” Anderson said in the press release.
With their data, the team was also able to compare sea ice loss with toxins in the whale samples. With minimal snow and ice cover, the sun’s rays warm the waters, leading to more algal blooms. Years with less ice saw an increase in toxins in the bowhead whales.
“Native communities know intimately the ecosystems they rely on and were among the first to recognize the effects of warming,” said Raphaela Stimmelmayr, a wildlife veterinarian with the North Slope Borough in Barrow, Alaska, and a coauthor of the new research in the press release.
This research indicates that these coastal communities will require access to more reliable toxic algae testing to ensure their food sources are safe to consume, or else figure out a way to bring back the sea ice.
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A graduate of UW-Whitewater, Monica Cull wrote for several organizations, including one that focused on bees and the natural world, before coming to Discover Magazine. Her current work also appears on her travel blog and Common State Magazine. Her love of science came from watching PBS shows as a kid with her mom and spending too much time binging Doctor Who.
