Climate Change, Overfishing Are Decimating Cod Populations

A new study cites rapidly warming Gulf of Maine waters as being the cause of a decrease in cod populations in New England, with the extra heat reducing the rate of reproduction while increasing mortality. Overfishing has already had a large effect on the fish population, and caps were put on commercial fishermen in an effort to reverse the decline. According to this new study, a failure to factor in warming temperatures means that cap was still too high, and the results of the two — warmth and overfishing — have largely been devastating.

Unfortunately, these cod populations have been declining for several years, with fishing caps having been imposed in 2010. Those limitations were severe, nearly eradicating sport/recreational fishing and greatly reducing commercial fishing. Still, it wasn't enough.

Water temperature data was used to determine how much warming the gulf has experienced between 1982 and now. Between 2004 and 2013, the gulf water temperature increased faster than that of 99.9-percent of ocean waters. The work was done by a collective of marine researchers, and will be detailed in a report published in Science tomorrow, according to the New York Times.

A shift in the gulf stream and a warming climate are both cited as likely reasons for the gulf's rapid warming. Mortality rates and warming temperatures were found to be related, something previously suspected, but the rapid rise in temperatures proved surprising. In the future, if the rising temperatures are factored into conservation efforts, researchers estimate it will take an extra 2 to 8 years in addition to the present decade or so estimate to rebuild the cod populations.

SOURCE: New York Times