C. S. Davis, S. M. Gallager, and C. Ashjian (all at WHOI)
A major goal of the GLOBEC Georges Bank Program in 1997 is to examine the immigration and emigration (source, retention, and loss) of target species from the bank. Toward this end, a field study is proposed in which focused high-resolution sampling will be conducted using the Video Plankton Recorder (VPR) to quantify the major processes controlling the transport of the copepods Calanus and Pseudocalanus across the boundaries of Georges Bank. The major processes to be studied include the inflow or source of copepods along the northern edge of the bank, the degree of closure of the gyre and retention of copepods, and the losses of copepods due to mean along-shelf flow to the west. Four VPR cruises (January, February, April, and June) are proposed to examine these processes during the spring development of the bank populations. Detrainment of bank copepods to the south by eddies and warm-core rings will be examined collaboratively with the Brink et al. SeaSoar/VPR study.
The proposed study will provide essential information on the processes affecting gains and losses of copepods from Georges Bank. These data will be used together with information on bank population structure (broadscale cruises) and vital rates in GLOBEC modeling studies of the processes controlling population abundance of these copepods on the bank. The combined effort of the GLOBEC Georges Bank Program will provide new insights into the dynamics of pelagic marine systems including mass/energy flow through the mesozooplankton, larval fish food availability, and potential effects of changing climatological forcing on zooplankton population abundance.