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(44-05) Hydrodynamic Investigation in the Caspian Sea, Looking for Back and Forth and Finding Up and Down. Newton, Frederick*,1, Richter, Kenneth2, Tait, Russell3, 1 Battelle Memorial Institute, Carlsbad, California2 U.S. Navy, SPAWAR Systems Center, San Diego, California3 ExxonMobil Production Company, Houston, Texas ABSTRACT- Hydrodynamic investigations were undertaken in two areas in the southern Caspian Sea between April 1999 and March 2001 to support the engineering design of drilling rigs, oil spill modeling, and monitoring of discharged muds and cuttings. Water current speed and direction were collected at 2 metre intervals, to a depth of 100 metres, using a 300kHz acoustic doppler current profiler (ADCP). Analysis of echo intensity data revealed distinct diurnal patterns, suggesting a substantial vertical migration of zooplankton. Relative biomass is estimated from acoustic amplitude and compared to incidental vertical zooplankton tows in which animals were identified and enumerated. Distinct diurnal patterns in vertical water velocity were also noted. Seasonal and spatial variations in these parameters are discussed. Key words: zooplankton, vertical migration, Caspian Sea , acoustic profiling |
