Sea surface temperatures difference from average in mid-June in mid-Atantic and Northeast (temperature scale in Celsius) (NOAA)

Over a region spanning Cape Hatteras, North Carolina to the Gulf of Maine, the average sea surface temperature (SST) was 51 degrees F (10.5 degrees C) , about 3 degrees higher than the average temperature in the last 30 years. The previous record high was set in 1951.

These water temperatures were especially high close to home in the mid-Atlantic.

“In some nearshore locations like Delaware and Chesapeake Bays in the Middle Atlantic Bight region, temperatures were more than 6 degrees C (11°F) above historical average at the surface and more than 5 degrees C (9°F) above average at the bottom,” NOAA said.

These warm bay and ocean water had important ecological effects.

“The 2012 spring plankton bloom, one of the longest duration and most intense in recent history, started at the earliest date recorded since the ocean color remote sensing data series began in 1998,” NOAA said.

The warm temperatures also likely affected the distribution of commercially-important fish, like cod.

“Atlantic cod distribution in the Gulf of Maine continues a northeasterly shift, with the spring 2012 data consistent with a response to ecosystem warming,” NOAA said.

A 2009 NOAA study documented four decades of SST warming along with changes in distribution of 24 of 36 fish stocks studied. Many of these fish species have been shifting north the study found.