Pelagic Fish Biomass Survey on the Africana Voyage 097, November 1991

The Pelagic Fish Biomass Survey was conducted on the Africana Voyage 097 from 07 November to 03 December 1991. The objectives of the cruise were to estimate the biomass and population length structure of anchovy, pilchard, and round herring off South Africa by means of echo-integration and midwater trawling; to estimate anchovy biomass by means of the egg production method, and trial estimate pilchard biomass by means of the egg production method; to describe the distribution and behaviour patterns of commercially harvested epi-pelagic and meso-pelagic fish, and the influence of oceanographic variables on these; to collect biological data on reproduction, condition and diet of pelagic fish species; to determine phytoplankton biomass in the nanophytoplankton (10 µm) size-classes in surface waters; to obtain information on the distribution and abundance of meso-zooplankton; to estimate secondary production rates of adult copepods using the egg production method; to investigate relationships between water temperature, phytoplankton size, phytoplankton biomass, copepod biomass and production, and the distribution of pelagic fish; the examination of feeding ecology and food production selection of pilchard; the retrieval of a current meter mooring off Cape Columbine; and profiling of currents by means of the acoustic doppler current profiler.