Saving Seafood

Marine animals live where ocean is most breathable, ranges may shrink with climate change

September 17, 2020 — As oceans warm due to climate change, scientists are trying to predict how marine animals—from backboned fish to spineless jellyfish—will react. Laboratory experiments indicate that many could theoretically tolerate temperatures far higher than what they encounter today. But these studies don’t mean that marine animals can maintain their current ranges in warmer oceans, according to Curtis Deutsch, an associate professor of oceanography at the University of Washington.

“Temperature alone does not explain where in the  an animal can live,” said Deutsch. “You must consider : how much is present in the water, how well an organism can take up and utilize it, and how temperature affects these processes.”

Species-specific characteristics, overall  and water temperature combine to determine which parts of the ocean are “breathable” for different ocean-dwelling creatures. New research led by Deutsch shows that a wide variety of marine —from vertebrates to crustaceans to mollusks—already inhabit the maximum range of breathable ocean that their physiology will allow.

Read the full story at PHYS.org

Ocean’s Oxygen Starts Running Low

May 3, 2016 — Climate change is doing more than warming the world’s oceans. It’s also making it harder for marine life to breathe.

Curtis Deutsch, associate professor at the University of Washington’s School of Oceanography, studies how increasing global temperatures are altering the levels of dissolved oxygen in the world’s oceans. Scientists have been warning that decreasing amounts of available oxygen will increase stress on a range of species, even as they also face the effects of rising temperatures and ocean acidification.

Deutsch’s latest research is untangling how much oxygen loss is linked to climate change and how much is due to normal variation in oxygen levels.

“As the climate goes up, the amount of oxygen will go down, but it’s really hard to look in the ocean to see that change,” he said.

Using an earth system modeling approach, Deutsch and scientists at the National Center for Atmospheric Research and the Georgia Institute of Technology mapped out changing oxygen levels across the world’s oceans through the end of the 21st century.

They found that it was possible to distinguish the impact of global warming from other sources of oxygen loss. As soon as 2030 to 2040, climate-driven declines in oxygen levels will be detectable in oceans all over the globe. In some places, like the southern Indian Ocean and parts of the eastern tropical Pacific and Atlantic basins, evidence of climate-linked deoxygenation is already apparent, while other regions won’t see changes by 2100.

Read the full story from Scientific American