Zooplâncton e zoonêuston na Bacia de Sergipe e sul de Alagoas

Abstract

This study characterized the structure of the zooplankton communities of the Sergipe and South Alagoas Basin in the rainy (May / June 2014) and dry period (December 2014) along seven isobaths: 10, 25, 50, 400, 1000, 1900 and 3000 m, with vertically stratified sampling. The tows were carried out with a Neuston net and with a MOCNESS net. The zooneuston presented nine phyla distributed in 119 taxa. The most abundant groups were Cnidaria, Teleostei, Copepoda and Decapoda. For the zooplankton sampled with MOCNESS, 428 taxa were identified in 12 phyla, where Copepoda contributed the most. Biomass and density decreased with distance from shore and depth. 95 taxa were detected in relation to the water masses: the species Belzebub faxoni, Acetes americanus, Centropages velificatus and Temora turbinata were indicators of coastal surface waters, whereas Undinula vulgaris and Acrocalanus longicornis indicated oceanic surface waters. The species Conaea rapax and Caecosagitta macrocephala were indicative of deep bathypelagic waters (AIW to NADW). The results of the Redundancy Analysis (RDA) applied to the zooplankton showed a distribution explained by spatiotemporal variables, where it was possible to observe two clear gradients: a vertical gradient (surface / deep layers) and a temporal gradient (rainy / dry season).