Current Conditions of the Northeast Shelf Ecosystem - Bloom Magnitude :: Ecosystems Dynamics and Assessment

Spring Bloom Start Day and Magnitude

The spring bloom typically starts earlier in the more southern segments of the Northeast Shelf Large Marine Ecosystem (LME). In 2016, the Northeast Shelf composite bloom start date was in mid-March, which was close to the time series average. However, bloom magnitude was nearly 16 mg m-1 8-day, which was the second lowest value in the time series. Spring bloom magnitude is one measure of bloom dimension and is calculated as the sum of chlorophyll concentrations during the bloom period. The Scotian Shelf, Georges Bank, and Middle Atlantic Bight ecoregions had low magnitude blooms due to their short duration, despite the high chlorophyll concentrations associated with these blooms. The Gulf of Maine bloom magnitude was close to the average for the time series. This analysis was based on a blended time series of MODIS and SeaWiFS remote sensing data that utilized a time and area correction between the two sensors.