Zooplankton are small organisms — like sea snails, jellyfish, and krill — and they’e crucial to the Bering Sea’s ecosystem. But new data from NOAA Fisheries shows that one of the most common zooplankton isn’t as fatty or abundant as it used to be.
Large, high-fat copepods — distantly related to shrimp and crab — are dwindling with the lack of sea ice from global warming. Meanwhile, smaller zooplankton are increasing in both numbers and range.
David Kimmel is a research oceanographer and leader of the nearly two-decade study. He said Arctic fish, seabirds, and marine mammals are struggling to adjust to global warming while consuming less fatty foods.
“They can get skinny — which doesn’t necessarily lead to mortality, but can make them more susceptible,” said Kimmel. “For example, not surviving in the winter if they don’t have enough energy stores to make it through the winter.”
While less fat in the diet doesn’t necessarily lead to extinction, Kimmel said it could lead to smaller population sizes of common Bering Sea organisms, like king crab and harbor seals. It could also create an ecological shift in the sea.
“Organisms that are normally found to the south are moving northwards,” he said. “So communities that you might expect to exist at more southerly latitudes begin to become more prominent at more northerly latitudes.”
The Bering Sea is one of the most sensitive regions to global warming. Kimmel said knowing how the bottom of the food chain changes with warmer temperatures can help predict how ecosystems around the world will be affected by climate change later on.
“The people that live in Alaska at the frontline of this change are really the ones that are experiencing it,” Kimmel said. “And they’re quite removed from a lot of fellow citizens throughout the country that aren’t experiencing it — you know, right up close and personal. And that makes their stories and their experiences much more important to share and talk about.”
