nuclear-news

Climate change could be shrinking the world’s fish

Because warmer seas speed up their metabolisms, fish, squid and other water-breathing creatures will need to draw more oxygen from the ocean. At the same time, warming seas are already reducing the availability of oxygen in many parts of the sea.

A pair of University of British Columbia scientists argue that since the bodies of fish grow faster than their gills, these animals eventually will reach a point where they can’t get enough oxygen to sustain normal growth.

“What we found was that the body size of fish decreases by 20 to 30 percent for every 1 degree Celsius increase in water temperature,” says author William Cheung, director of science for the university’s Nippon Foundation—Nereus Program.

These changes, the scientists say, will have a profound impact on many marine food webs, upending predator-prey relationships in ways that are hard to predict.

Lab experiments have shown that it’s always the large species that will become stressed first,” says lead author Daniel Pauly, a professor at the university’s Institute for the Ocean and Fisheries, and principal investigator for the Sea Around Us. “Small species have an advantage, respiration-wise.”

Still, while many scientists applaud the discovery, not all agree that Pauly’s and Cheung’s work supports their dramatic findings. The study was published today in the journal Global Change Biology…….http://www.nationalgeographic.com.au/animals/climate-change-may-shrink-the-worlds-fish.aspx

August 23, 2017 - Posted by Christina Macpherson | 2 WORLD, climate change, oceans