(File photo credit The Nature Conservancy)
Several years ago, an interest in mercury levels in the Kotzebue Sound prompted the local village authority to commission a study from the University of Alaska Fairbanks. Last month, researchers came back with good news. Mercury levels in Kotzebue-area subsistence fish are safe.
When mercury gets into water, it changes chemically and is prone to affect local marine ecosystems.
“Under perfectly ideal conditions, you can get mercury that accumulates in fish,” said Andrew Cyr, one of the UAF researchers looking at Kotzebue-area fish.
While mercury occurs naturally, it is sometimes released in larger quantities by mining.
“And you can get concentrations that can actually be considered unhealthy for consumption, particularly for pregnant and nursing women,” Cyr said.
Cyr says that those conditions vary based on mercury levels in the area. Because of Kotzebue’s proximity to the Red Dog Mine — about 80 miles — a UAF release says locals were worried, in part, about the effect that the mine’s discharge could have on local fish populations.
Alex Whiting, Environmental Director for the Village of Kotzebue, says that pollution is a valid concern, but the village was more interested in getting a general baseline for the safety of their fish.
“It was more about not knowing what the mercury levels were,” Whiting said. “Our environment here, relative to the rest of the planet, is pretty clean. So our assumption was that our fish would be also pretty clean.”
Whiting says studies on mercury levels in Kotzebue waters had been done in 2008, but it was more focused on sheefish and spotted seals.
“Mercury bioaccumulates as it moves up the food chain,” Whiting said. “So at the time when we did that first study, it was focused on those top predators because if the levels of mercury in those were not concerning, then you can assume that all the food chain below them also have levels that aren’t concerning.”
He says this study was more robust, looking at various fish at different levels. Cyr with UAF says that local fishermen were very cooperative with the study, allowing researchers to take samples from hauls from 2015, 2016 and 2018.
“They opened their doors. They opened their fish nets. They donated fish,” Cyr said. “We had help getting around out on the ice and out on the shore. The community really helped us out with a lot of this research.”
Overall, researchers looked at 297 fish from eight species — chum salmon, fourhorn sculpin, least cisco, humpback whitefish, starry flounder, Pacific herring, Pacific tomcod and sheefish.
Cyr says the highest levels in mercury came from the predatory sheefish and larger fish in general.
“It seems that we can definitely detect mercury accumulating in fish as they get bigger,” Cyr said. “Basically, as they get longer, mercury is accumulating in them more.”
The average level of mercury in all of the species of local fish was found to be safe to eat. Whiting with the village is pleased with the results.
“Our fish are good,” Whiting said. “You can eat as much of our fish as you want, and it’s not going to damage you, even if you’re young or pregnant.”
Whiting says he’s hopeful that studies will be done regularly to keep the area updated on mercury.
“Mercury levels aren’t static, you know. They change over time,” Whiting said. “And so hopefully in the future, we’ll be able to do the same thing, and then we’ll have levels to compare and understand if there are changes of if there are levels of concern.”
Whiting says UAF and the village have been strong partners in the past, and he hopes that continues in the future.
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