U.S. GLOBEC: Dispersive and Advective Influences on the Survival of Cod and Haddock on Georges Bank

R. G. Lough, J. P. Manning, E. M. Caldarone, L. J. Buckley, and L. S. Incze

As part of U.S. GLOBEC II Georges Bank Study, we will conduct an interdiciplinary field project in April and May 1997 to better understand the relative importance of dispersive and advective processes affecting retention/loss, feeding, growth rates, and nutritional condition of larval cod and haddock along the southern flank of Georges Bank. Important physical processes that have both retention and loss aspects are: on-off-bank subsurface flows, bifurcating flow at the Great South Channel, wind-driven advection, warm-core rings, and shelf-front eddies. Important biological processes that have a bearing on retention include factors that affect their position in the water column, such as vertical migration, swimming capacity, prey distributions and growth. The field sampling strategy and instrumentation include a combination of grid surveys, cross-bank transects, and fixed-site studies which have been designed to make measurements on the time and space scales relevant to larval fish and their copepod prey. The project implements a modeling component, where a three-dimensional circulation model will be used in near real-time to conduct the field program, as well as in hindcasting mode to integrate all the physical and biological observations in coupled simulations. The data and model results will be used to evaluate the interrelations and relative importance of larval swimming behavior, physiological condition, buoyancy, and physical retention and loss processes.

NSF/NOAA Proposal #9632761