Atlantic Salmon can Adapt to Warm Waters

Atlantic salmon can cope with climate change, a new study has found.

The study, conducted by researchers at the University of Oslo and University of British Columbia, has found that populations of Atlantic salmon have the ability to adjust to warmer temperatures.

For the study, researchers looked at salmon populations in two European rivers. The team compared fish population from Norway's northern Alta River with fish population in France's Dordogne River. The temperature of the Alta river hasn't exceeded over 18 degree C in 30 years, while the river in France regularly registers temperatures above 20 degree C.

The team then obtained eggs from both the fish populations and hatched them at the University of Oslo. The fish were raised at either 12 or 20 degree C. Researchers found that the salmon populations were remarkably similar despite growing at different temperatures.

Researchers tracked heat tolerance by tracking heart rates of fish.

When reared in 12 degree C water, salmon from both populations developed irregular heartbeats at 21 to 23 degree C. Surprisingly, fish that grew up in 20 degree C water developed cardiac arrhythmias at 27.5 degree C.

Researchers also found that increasing the fish's acclimation temperature by 8 degree C led to an increase in temperature tolerance by 6 degree C.

"The results are surprising," Tony Farrell, Chair in Sustainable Aquaculture, said in a news release. "A fish faced with uncomfortably warm temperatures might relocate or even die if it is too extreme. Here we have evidence for warm acclimation of a commercially and culturally important fish species."

This research adds to a previous finding that stated that Pacific salmon can cope with warm temperatures. That study had found that Chinook salmon that lay larger eggs had offspring with heat tolerance capability.

The study is published in the journal Nature Communications