O zooplâncton da plataforma continental de Santa Catarina. Ênfase em Copepoda e Cladocera e suas relações com os processos físicos costeiros

Abstract

Studies intended exclusively for the investigation of the zooplankton community from the continental shelf of Santa Catarina State had not yet been achieved despite the economic and ecological importance of the area. This coastal region of southern Brazil presents high relevant oceanographic processes as a strong influence of continental inputs, upwelling at Cape Santa Marta Grande and the influence of the Plate Front from the south. Due to this complexity hydrology two cruises were made, December 2005 and May 2006, aiming to study the temporal variations of these processes and their influences on biota. For this study, samples of zooplankton collected by oblique hauls with Bongo net at 33 sampling points arranged in profiles perpendicular to the coast for each cruise were analyzed. The dominant groups in the samples were Copepoda, Cladocera, Chaetognatha and salps, with highest densities in coastal points. For the cruise of December 2005 the temperature and salinity gradients perpendicular to the coast, driven by continental inputs on north and upwelling on south of the area, determined the distribution limits of Acartia lilljeborgi and Penilia avirostris. In May 2006 cruise, due to less variation in temperature and salinity, the longitudinal gradients to coast could not explain the variation of species distribution, indicating that biotic forcings could be acting in the ecology of the system