Project Summary

Peter H. Wiebe and Timothy Stanton

U. S. GLOBEC: Broad-scale Patterns of the Distribution of Zooplankton and Nekton in relation to micro- to coarse-scale physical structure in the Georges Bank Region

As part of the U.S. GLOBEC NW Atlantic/Georges Bank study, we will use high frequency acoustics to study the relationship between the distribution of zooplankton and nekton populations on Georges Bank and the physical environment. The work will be a continuation the acoustic survey work that has been conducted on previous broad-scale cruises of the entire Bank. The work will take place on three of the six broad-scale cruises in 1999 (January, March, June) with the Greene Bomber equipped with 2 frequencies and an Environmental Sensing System which includes(temperature, conductivity, pressure, fluorescence, and downwelling light). The two-frequency system containing split-beam technology will provide high spatial resolution estimates of volume backscattering and target strength of plankton and nekton throughout the Georges Bank region. These data together with theoretical models will be used to interpret the acoustical data in terms of meaningful biological properties, such as biomass and size distribution. The physical sensors will provide the information about fine- to coarse- scale surface physical structure of the Bank environment. The broad-scale acoustical spatial maps will provide detailed information about location and structure of frontal features on the Bank and will enable the linkage between the physical oceanographic conditions on the Bank and the biological distributions of the species throughout the Georges Bank region.