2015-10-29. Collapse of New England’s iconic cod tied to climate change.

posted Oct 31, 2015, 1:28 PM by Alan Gould
By Marianne Lavelle, Science. For GSS Climate Change chapter 8 and Losing Biodiversity chapter 6. Excerpt: The Atlantic cod, a fish that came to symbolize bounty to America’s colonial settlers, is on the brink of disappearing, despite years of fishing limits aimed at rebuilding stocks. A new study reveals why: Cod spawning and survival has been hampered by rapid, extraordinary ocean warming in the Gulf of Maine, where sea surface temperatures rose faster than anywhere else on the planet between 2003 and 2014. ...The scientists used satellite data to track the daily sea surface temperature trend in the Gulf of Maine. From 1982 until 2004, they found, temperatures rose by 0.03°C per year, or three times the global mean rate. That warming accelerated sevenfold beginning in 2004, peaking in 2012 with a large “ocean heat wave” that persisted for 18 months, according to the study. ...Using recent Gulf of Maine cod stock assessments, the researchers then tested a number of models for predicting the factors that affected cod reproduction. Warming was the best predictor, they reported: When summer temperatures went up, the number of fish reaching maturity went down. “The number of new cod for each year that appear in the population is strongly related to temperature,” Pershing says....  http://news.sciencemag.org/climate/2015/10/collapse-new-england-s-iconic-cod-tied-climate-change