Relationship Between Ichthyoplankton Abundance and Associated Zooplankton Biomass in the Shelf Waters off Argentina

AbstractZooplankton and ichthyoplankton volumes, and larval fish abundance, were determined for 689 stations established during 18 exploratory cruises in the sea off Argentina. Zooplankton density distributions throughout the year in relation to water temperature are presented. The equation Y = 5.89 × 0.78 was calculated and used to transform data on volumes obtained with a 505-μ-mesh net and compared then with those obtained with a 330-μ-mesh net. Strong negative correlations were observed between the volumes occupied by eggs of zooplanktophagous fish species and associated net zooplankton biomass: Micromesistius australis (r =—0.92); Sprattus fuegensis (r =—0.82); and Engraulis anchoita (r =—0.94). No significant relationships were obtained between the egg volumes of ichthyophagous species and associated net zooplankton biomass, and between fish larvae abundance and zooplankton volumes, though in this case a general positive tendency was observed. Zooplankton and ichthyoplankton abundances in two fishin...