Greenhouse Ocean May Downsize Fish

The last fish you ate probably came from the Bering Sea.

But during this century, the sea’s rich food web—stretching from Alaska to Russia—could fray as algae adapt to greenhouse conditions.

“All the fish that ends up in McDonald’s, fish sandwiches—that’s all Bering Sea fish,” said USC marine ecologist Dave Hutchins, whose former student at the University of Delaware, Clinton Hare, led research published Dec. 20 in Marine Ecology Progress Series, a leading journal in the field.

At present, the Bering Sea provides roughly half the fish caught in U.S. waters each year and nearly a third caught worldwide.

“The experiments we did up there definitely suggest that the changing ecosystem may support less of what we’re harvesting—things like pollock and hake,” Hutchins said.

While the study must be interpreted cautiously, its implications are harrowing, Hutchins said, especially since the Bering Sea is already warming.

“It's kind of a canary in a coal mine because it appears to be showing climate change effects before the rest of the ocean,” he noted.

“It’s warmer, marine mammals and birds are having massive die-offs, there are invasive species—in general, it’s changing to a more temperate ecosystem that’s not going to be as productive.”

Carbon dioxide’s direct effects on the ocean are often overlooked by the public.

“It’s all a good start that people get worried about melting ice and rising sea levels,” he said. “But we're now driving a comprehensive change in the way Earth's ecosystem works—and some of these changes don't bode well for its future.”