Warming seas could push some fish species to limit: study
(Reuters) - Rapidly warming ocean temperatures in some parts of the world could be pushing some fish species to the limit, stunting their growth, increasing stress and raising the risk of death, a study shows.
An Australian study, published on Monday in the journal Nature Climate Change, focused on the long-lived fish species called the banded morwong in the Tasman Sea, between Australia and New Zealand.
Scientists, using long-term and current data, found that the morwong's growth in some areas has been slowed by a jump in sea surface temperatures of nearly 2 degrees Celsius over the past 60 years in the Tasman Sea, one of the most rapid increases in the southern hemisphere's oceans.
The results have implications for other fish species, including commercial fisheries, as seas heat up and become more acidic, affecting coral reefs and multi-billion dollar fisheries dependent on them.
Generally, cold-blooded animals respond to warming conditions by boosting growth rates as temperatures rise, said marine ecologist Ron Thresher of Australia's state-backed research body the CSIRO. But there was a limit.
"By examining growth across a range that species inhabit, we found evidence of both slowing growth and increased physiological stress as higher temperatures impose a higher metabolic cost on fish at the warm edge of the range," Thresher told Reuters from Hobart, Tasmania.