World Economic Forum —
Laboratory experiments indicate that many marine creatures 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, says Curtis Deutsch, a professor of oceanography at the University of Washington.
“Temperature alone does not explain where in the ocean an animal can live,” says Deutsch. “You must consider oxygen: 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 oxygen levels, and water temperature combine to determine which parts of the ocean are “breathable” for different ocean-dwelling creatures.
The findings in Nature also provide a warning about climate change: Since warmer waters will harbor less oxygen, some stretches of ocean that are breathable today for a given species may not be in the future.