The Northeast Continental Shelf Large Marine Ecosystem (LME) extends from the Gulf of Maine to Cape Hatteras, N.C.
The average sea surface temperature (SST) exceeded 51.0 degrees F during the first half of 2012, breaking the previous record high set in 1951. For the past three decades, the average SST has been 48 degrees F.
In some nearshore locations such as the Delaware and Chesapeake bays in the Middle Atlantic Bight region, temperatures were more than 11 degrees F above historical average at the surface and more than 9 degrees F above average at the bottom.
"A pronounced warming event occurred on the Northeast Shelf this spring, and this will have a profound impact throughout the ecosystem," said Kevin Friedland, a scientist in the NEFSC's Ecosystem Assessment Program.
"Changes in ocean temperatures and the timing of the spring plankton bloom could affect the biological clocks of many marine species, which spawn at specific times of the year based on environmental cues like water temperature."
This was observed in an earlier and longer-than-usual annual plankton bloom.
Atlantic cod were also observed continuing to shift northeastward from its historic distribution center.
The warming of these surface temperatures may be caused by a natural phenomenon called Atlantic Multidecadal Oscillation, or AMO, said AccuWeather.com Expert Meteorologist Brett Anderson.
AMO is an ongoing series of long-duration changes in the sea surface temperature of the North Atlantic Ocean. It's marked by both cool and warm phases that may last for 20-40 years at a time, according to NOAA.
"The temperatures changes are more than likely just a natural occurrence. We have been in a warm phase for quite a while now, with a lot more warmer water than usual across the North Atlantic," Anderson said.