Fish can adapt some to warmer ocean waters, but not necessarily to extreme heat

http://www.eurekalert.org/pub_releases/2016-05/nuos-fca051816.php

Public Release: 18-May-2016
Fish can adapt some to warmer ocean waters, but not necessarily to extreme heat
Plastic floors and concrete ceilings define a fish's metabolic limits when it comes to climate change.
Norwegian University of Science and Technology

Fish can adjust to warmer ocean temperatures, but heat waves can still kill them, a team of researchers from Sweden, Norway and Australia reports in an article published this week in Nature Communications.

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In other words, Jutfelt said, the fish are living very close to their lethal limit.

"They have a very small safety margin to their lethal temperature," he said.

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If this finding holds true for other fish species, he said, then fish living in northern lakes or the ocean may appear to be healthy even as water temperatures climb. But if waters warm too much, from a strong heat wave, the apparently well-adapted fish populations might die, he said.

"We think this might be important in fish (overall), the fact that they might not be able to adjust their tolerance to maximum levels," he said. "We think that might be the bottleneck for survival."

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