DinÃmica em microescala do mesozooplÃncton do ArquipÃlago de SÃo Pedro e SÃo Paulo â NE, Brasil

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Plankton samples were collected (May/08) with a 300 μm mesh size net to assess smallscale variation patterns and for spatially comparisons among composition, distribution and abundance of the main zooplankton groups in Saint Peter and Saint Paul Archipelago (SPSPA). Sampling was carried out in two stations (Enseada and CabeÃo da Tartaruga) during five consecutive days, during early morning and late afternoon. 154 zooplankton taxa were identified. Copepoda was the most abundant and frequent group (50), eggs of Exocoetidae (Teleostei) were also important. Significant differences were not found between stations or day-night samples. The biomass was low, however superior to those observed in open ocean. The density was low, increasing slightly during the night. Indicators species for upwelled waters were registered, such as Phaenna spinifera and Flaccisagitta hexaptera. In another sampling design, sampling was carried out on four perpendicular transects to the archipelago, composed by four stations, each one half nautical mile from the other. 106 zooplankton taxa were identified, of which 37 were Copepoda. There was a decrease in the values of density, biomass and diversity when moving away from SPSPA, evidencing the island effect. With the arrival of the South Equatorial Current (SEC) (West portion) a homogenization of the community occurred. The SEC acts in structuring the community and it is the main responsible for the island effect in the region

ASSUNTO(S)

oceanografia seamount topographic upwelling ressurgÃncia topogrÃfica monte submarino mesozooplÃncton mesozooplankton

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