A Small Antarctic Fish Is Helping Scientists Understand The Impacts Of Climate Change

The emerald rock cod looks like a fish you might find off the California coast, but it's actually an Antarctic species that emperor penguins and seals rely on for food.

UC Davis biologist Anne Todgham and her fellow researchers wanted to find out how a species that's lived under very stable conditions for more than 10 million years would cope when faced with environmental stressors linked to climate change. Specifically, they sought to learn how the species would respond to rising ocean temperatures and higher acidity levels.

So Todgham and her colleagues set up an experiment at a lab in Antarctica. They studied juvenile emerald rock cod for a month, using water temperatures of 2 degrees celsius, a temperature scientists predict could be the norm by the year 2100. They varied the amount of carbon dioxide in each control group.

"If you expose these fish to a single stress — just warming or just acidification — the animals are able to cope with the stress," explains Todgham. "But when you give the two stressors they lose that ability to cope."

The study was recently published in the journal Global Change Biology.

She says the research is part of a broader scientific effort to identify which species and ecosystems are most vulnerable to climate change. That data, in turn, could shape policies to protect animals from environmental stressors that are preventable in the short-term, such as habitat destruction and over-fishing.

As for why Californians should care about a little fish at the bottom of the world, Todgham points out that because of air circulation patterns and currents, Antarctica is still impacted by what we do.

And, she adds, connecting the public with science being done outside of California (and as far away as different polar regions) can demonstrate that climate change is a global problem.

Todgham says, "(It shows) there are impacts that are right here, locally, and there are impacts far away and that climate change needs our immediate attention."