The objective of this study was to quantify and to model zooplankton transport with emphasis on decapod crustacean larvae. Sampling was carried out at three depths with a plankton pump coupled to a 300-/¿m mesh. Current data were obtained with an ADCP. Our data showed the existence of vertically and horizontally heterogeneous current and transport fields. We identified 27 groups of Decapoda (larvae of Sergestidae, Porcellanidae, Upogebiidae, Cari dea, Brachyura). Most of the species and larval phases showed characteristic vertical migration patterns, in phase with the diurnal tidal cycles, thus enhancing retention or export from the estuary.

Esta investigación tiene como objetivo cuantificar y modelar el transporte de zooplancton, con énfasis en las larvas de Crustacea Decapoda. El muestreo se realizó a tres profundidades con una bomba de plancton acoplada a una red con malla de 300 /¿m. Se obtuvieron los datos de corrientes con un ADCP. Los datos mostraron la existencia de campos de corrientes y de transporte vertical y horizontal heterogéneos. Se identificaron 27 grupos de Decapoda (larvas de Sergestidae, Porcellanidae, Upogebiidae, Caridea, Brachyura). La mayoría de las especies y fases larvales mostraron patrones de migración vertical característicos, en fase con los ciclos de la marea diurnos, favoreciendo la retención o exportación del estuario.

Este trabalho objetivou quantificar o transporte da biomassa zooplanctônica entre o Canal de Santa Cruz (CSC), na Barra de Catuama, e a plataforma adjacente no sistema estuarino de Itamaracá, Nordeste do Brasil. As coletas foram realizadas em agosto/2001 durante as marés de sizígia e quadratura em três estações a cada 3 horas. As coletas foram em três profundidades com auxílio de bomba acoplada à rede de plâncton com 300 µm de abertura de malha. Dados de corrente foram obtidos com perfilador acústico de corrente (ADCP). Em laboratório, as amostras foram pesadas para obter o peso úmido. Foram registradas grandes variações na biomassa com valores mais altos nas marés enchente e vazante noturna durante maré de sizígia. O transporte instantâneo médio da biomassa foi de 139,48 ± 72,58 mg.m-2.s-1, durante a sizígia, e de 36,63 ± 27,66 mg.m-2.s-1, durante a quadratura. Os fluxos de importação e exportação não apresentaram diferenças significativas (p > 0,05), evidenciando exportação e importação de grande quantidade de biomassa no período chuvoso. Conclui-se que a exportação do CSC é alta, porém diferentemente de outros locais, a importação também é alta, possivelmente pela presença de recifes e prados de fanerógamas (Halodule wrightii) em direção à plataforma, criando um ambiente produtivo distinto.

The objective of this study was to quantify the zooplankton biomass transport between the Santa Cruz Channel (SCC) at Catuama north inlet and the adjacent shelf located in Itamaracá estuarine ecosystem, Pernambuco State, Northeastern Brazil. Sampling was carried out in August 2001 at spring and neap tides at three stations every 3-hour interval. Collections were made in three depths with a plankton pump coupled to a 300 µm mesh size net. Current data were obtained with an ADCP (Acoustic Doppler Current Profiler). In laboratory, samples were filtered for wet weigh determination. High biomass variation was recorded, with highest values at nocturnal flood and ebb during spring tide. The average instantaneous biomass transport was 139.48 ± 72.58 mg.m-2s-1, during spring tide and 36.63 ± 27.66 mg.m-2s-1, during neap tide. No significant difference was registered between importation and exportation flows (p > 0.05), showing that the estuary both exports and imports high biomass during the rainy season. It can be concluded that the outwelling at SCC is high, however, differently from other places, importation is also high, probably due to the presence of reefs and patches of seagrass (Halodule wrightii) toward the shelf that create a distinct productive environment.