Spring 2007 Update: Annual Phytoplankton Cycle-Georges Bank
The annual phytoplankton cycle for the Georges Bank in 2006 is overlaid on the climatological cycle for comparison (see top panel). The spring bloom was earlier and had a higher than average concentration, where the fall bloom was of average concentration. The duration of the fall bloom was difficult to estimate, so climatological data was used to estimate the start and end points of the fall and early winters period in 2006. Late winter and summer conditions were consistent with the long term average. Seasonal chlorophyll concentration and integrated seasonal chlorophyll concentration are presented for the five time periods used to represent the Georges Bank annual phytoplankton cycle (see bottom panel). Concentration showed an increase in all time periods except early winter during 2006; however, integrated concentration was low for the spring and fall bloom periods reflecting the short duration of the spring event and the average concentration of the fall event. Spring bloom has gone through a period of relatively increased concentration and magnitude during the period 2000-2004, but has declined in the last few years. Fall bloom has been at low levels since 2003.