A bowhead whale breaches in Alaska waters.
Analysis of bowhead whale poop shows that more toxins from typically warm-water toxic algae species are entering Arctic food webs as northern oceans warm and lose sea ice.
The findings are based on nearly 20 years of feces samples collected from bowhead whales harvested for subsistence purposes by Alaska Native people living on the Beaufort Sea coast.
The study, conducted by an interdisciplinary team led by the National Oceanic and Atmospheric Administration, was published in July in the journal Nature. University of Alaska Fairbanks co-authors included Rick Thoman and Gay Sheffield.
"The results of this long-term project underscore the level and quality of novel, impactful information that results when peoples, coastal Alaskans and urban-based scientists, work as a team to share their diverse backgrounds and expertise toward a common goal-in this case, harmful algae in the Arctic food web," said Sheffield, a UAF Alaska Sea Grant Marine Advisory Program agent based in Nome.
"We had the biology and whale experts, algae and toxin experts, physical oceanographers, climate experts and community level representatives," added Thoman, a climate specialist at the UAF Alaska Center for Climate Assessment and Preparedness. "It enabled questions to be answered that were no one's specialty."
The team used 205 feces samples collected by hunters during the fall as part of a monitoring program led by the North Slope Borough and the Alaska Eskimo Whaling Commission, in collaboration with 11 bowhead whaling communities. The program tracks baseline data on the whales' life history and natural diseases, as well as other threats in Arctic waters.
Bowhead whales are considered excellent indicators of the health and structure of marine food webs. They feed mostly on tiny aquatic animals called zooplankton. Since zooplankton ingest algae, bowhead whales are an ideal species for tracking the presence of algal toxins.
Harmful algal blooms occur when certain species of algae are high in abundance and produce toxins that have harmful effects on wildlife and humans. Increasing algal toxin concentrations could threaten food safety for coastal communities in northern and western Alaska that rely on bowhead whales for their nutritional, cultural and economic well-being.
Until now, little data existed on the changing exposure to harmful algal toxins in the Arctic. The use of archived whale feces allowed scientists to go back in time to better understand harmful algal concentrations over the past 19 years.
The study showed that higher algal toxin concentrations in the whale poop were strongly correlated with larger areas of ice-free waters and the resulting warmer ocean temperatures. This is presumably because algae can germinate four to eight times more quickly in the increasingly warmer waters of the Beaufort Sea.
