Spring 2009 Update: Summary of Conditions of the Northeast Shelf Ecosystem
Sea surface temperature (SST) in the Northeast Shelf Large Marine Ecosystem during the second half of 2008 moderated from the warming trend of the first half of the year.
Problems with the SeaWiFS ocean color sensing satellite make the 2008 chlorophyll data used in this report provisional. Despite the provisional nature of the data, it is clear that there were exceptional spring and fall phytoplankton blooms on the Northeast Shelf. The fall bloom was initiated early with bloom activity in the Middle Atlantic Bight. In 2008, chlorophyll a concentrations, which are an indication of primary productivity, were among the highest observed in the satellite data time series.
Zooplankton biomass levels were average or above during most of the year.
The contribution of krill (euphausiids) to the diet of herring has been shown to be episodic and appears related to fall phytoplankton blooms.
Students from regional schools contributed to efforts to measure ocean currents by constructing drifter buoys. These buoys provide data for direct measurement of currents and to evaluate circulation models.
Analyses of sea surface temperature over the past 26 years suggest that the critical transitional thermal habitat of the Northeast Shelf ecosystem has been constricted by changes in temperature conditions.
In 2008, selected subregions of Northeast Shelf ecosystem experienced both extremely high monthly summer SSTs and extremely low winter SSTs, based on historical data dating back to 1854.