Climate Change Is Causing Fish to Shrink

[Judi Lynn]

By Jen Viegas, Seeker | August 23, 2017 11:48am ET


Fishermen over the past several years have noted that fish appear to be shrinking. That observation was validated in 2014 by research that found commercially important fish stocks in the North Sea, such as sole, herring, and haddock, have decreased in maximum body size over a 40-year period. Scientists suspected that climate change was the culprit, but were unsure how warming waters could lead to fish shrinkage across entire species.

New research published in the journal Global Change Biology describes the mechanism that is likely causing fish to shrink. Lead author Daniel Pauly, a principal investigator with the Sea Around Us project at the University of British Columbia, said the findings apply to animals with gills, such as fish, sharks, squid, and lobsters.

Pauly's co-author William Cheung, director of science for the Nippon Foundation Nereus Program at the university, explained that these species and many others are ectotherms, meaning that their body temperature depends on environmental temperature.

"As the oceans warm up," Cheung said, "their bodies will do so as well. Higher temperature within the scope that the fish can tolerate generally increases the rate of biochemical reactions in the fish's body and thus increases their body metabolic rate."

More:
https://www.livescience.com/60211-climate-change-is-causing-fish-to-shrink.html?utm_source=notification

[Xipe Totec]

1. A simpler explanation is natural selection via fishing nets

Smaller fish slip through the nets while larger fish get caught. Similar evolutionary pressure is causing elephant tusks to shrink; the smaller the tusk, the less attention from poachers.

I'm not saying climate change isn't occurring, I'm just saying fish size has other factors which the article neither considered not addressed.

[Judi Lynn]

2. Real food for thought, Xipe Totec. It would never have occurred to me. Thanks. n/t