ZOOPLANKTON COMMUNITY STRUCTURE IN CONTINENTAL RUNOFF AND COASTAL UPWELLLNG CONDITIONS AT SANTA MARIA, COLOMBIAN CARIBBEAN

Abstract

Variation in the taxonomlc and trophic structure of the zooplankton community, associated to fertilizations alternating between continental runoff and coastal upwelhng. were studied in the nenttc province of the Santa Maria area. Colombian Caribbean Sea. Sampling was carried out In November 1991 during the major rainy season, and in April 1992 during the dry season. Organisms were Identified, counted and trophically placed, and the biomass por trophic levo! was dotorminod. Eighty-two spocies-taxa were discriminated, most ot them oceaniccoastal and predominantly omnrvores. Community composition varied temporally and spatially with predominant oceanographic conditions, evidoncmg succossional procossos rotatod to fertilization pulses. During continental runoff conditions, typical of the rainy season, community composition and total biomass and abundance were spatially more heterogeneous, with species more coastal and neritic, large omnivores and detritivores and small carnívoros. Dunng upwellmg conditions, which occur as localizod pulses during the rainy season, and generalize throughout the study area during the dry season, the community was spatially more homogeneous, with spocies more ocoanic and doop-dwolhng and. in its maximum development, with higher biomasses. omnivores and detritivores small, and greater representation and size of macrofiltering herbivores and carnivores.