9313671 Beardsley Present evidence indicates that the recruitment and survival of commercially important fish larvae within the Georges Bank region depends critically on the development of stratification during the spring and summer period. Predicted climate change scenarios are likely to significantly influence the evolution of stratification and thus impact larval survival over Georges Bank. As part of U.S. GLOBEC Georges Bank Study, Dr. Beardsley and collaborators will conduct an intensive field project during January-August, 1995 aimed at better understanding the development of stratification over Georges Bank and its influence of larval fish survival. Preliminary studies will be initiated in 1994. The project will have a moored instrument component will involve deploying meteorological sensors and instruments throughout the water column, with a heavy concentration in the surface and bottom boundary layers. The data acquired will be used to resolve the stratification field and examine factors controlling its development. The shipboard measurement component will consist of five cruises following a concentration (patch) of the target species: cod and haddock larvae and their copepod prey, Calanus and Pseudocalanus. Using a variety of sampling systems,including drifters, MOCNESS, the Video Plankton Recorder (VPR), plankton pump, and multiple- high-frequency acoustical samplers, measurements will be made of: (1) hydrography, microturbulence, and currents, (2) the vertical and horizontal distributions of the target species in relation to water column stratification, (3) passive particle motions and the tree-dimensional swimming behaviors of individual zooplankton, and (4) the feeding and growth of larval cod and haddock in relation to water column stratification and prey distribution. The data will be used together with information from collaborative field and modeling studies to gain insights into the impact of stratification and turbulent mixing on gro wth and survival of zooplankton and fish populations.
