U.S. GLOBEC: A Retrospective Analysis of Variability in Zooplankton Composition on Georges Bank and the Northwest Atlantic

Andrew R. Solow and Stephen M. Bollens

There are three parts to this project. In the first part, we will appy a newly developed statistical technique to MARMAP zooplankton data covering the period 1977-1987 to identify trends in zooplankton composition on Georges Bank and in three adjacent regions - the Gulf of Maine, Southern New England, and the Mid-Atlantic Bight. Three hypothesized factors controlling zooplankton communities are size-selective predation, mesoscale advective or "wash-out" events, and vertical mixing. In the second part of the project, we will use historical data on predator abundance, sea surface temperature, and wind and thermal stratification to develop predictions about the expected effects on regional zooplankton composition of historical variations in these factors and we will compare these predictions to observed trends. This regional focus increases the statistical power of the analysis. In the third part of the project, we will extend the analysis beyond the MARMAP period by incorporating data both from earlier surveys (Atlantis, 1939-1941; Continuous Plankton Recorder, 1962-1989) and from Phase I GLOBEC cruises (1994-1996).