Warming Atlantic Waters Affecting Fish Stocks

A dramatic rise in water temperature along the continental shelf of the mid-Atlantic and northeast coastlines has created a demonstrable shift northward in the distribution of several fish and mollusk species.

fish movements

fish movements

This map shows that many fish stocks have shifted to the north and northeast off northern states in recent years.Janet Nye, NEFSC/NOAA

Whether you believe in Global Warming or not, a recent report from the National Marine Fisheries Service announced that in 2012 surface-water temperatures along the continental shelf from Cape Hatteras, North Carolina, to Maine rose to the highest levels recorded in 150 years. During the previous three decades, water temperature has been below 12.4 degrees C. (54.3 F.), but it soared to 14 degrees C. (57.2 F.) in 2012.

A nearly three-degree Fahrenheit increase may not sound like much, but this is the highest recorded temperature since 1854 and one of only five times where water temperature rose by more than 1.8 degrees F. I’ll put it another way — I live in Ft. Lauderdale, Florida, and my pool is a lot more comfortable now than it was when it was three degrees cooler a month ago.

In case you were wondering, by the way, water temperatures in the region are based on contemporary satellite remote-sensing data and long-term ship-board measurements, according to NMFS, with historical temperatures based on ship-board measurements dating back to 1854.

This rise in water temperature has created a demonstrable shift in the distribution of several fish and mollusk species. Black sea bass, summer flounder, longfin squid and butterfish have all been shown to have shifted their distribution northward up the shelf, apparently taking advantage of the warmer water. This confirms the findings of another report published in 2009 that stated about half of the 36 fish stocks studied in the Northwest Atlantic Ocean have been shifting northward during the past four decades.

Scientists conclude this is clear evidence that the ecosystem of the northeast continental shelf is changing. What the future holds is largely unknown at this time. However, should water temperatures continue to rise, folks in New Jersey may get to supplement their summertime fluke with a little tarpon fishing.