Environmental variables and intertidal beach annelids of São Sebastião Channel (State of São Paulo, Brazil)

Benthic annelid communities were studied during a one-year period (August/95 to July/96) in two sectors of the beaches Engenho d’Água and São Francisco, São Sebastião Channel (São Paulo, Brazil), where the substrate is composed by a mixture of sand and rock fragments. Abiotic parameters such as sali...

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Bibliographic Details
Main Authors: Alexandra E Rizzo, A. Cecília Z. Amaral
Format: Article
Language:English
Published: Vicerractoría Investigación 2001-12-01
Series:Revista de Biología Tropical
Subjects:
Online Access:http://www.scielo.sa.cr/scielo.php?script=sci_arttext&pid=S0034-77442001000300002
Description
Summary:Benthic annelid communities were studied during a one-year period (August/95 to July/96) in two sectors of the beaches Engenho d’Água and São Francisco, São Sebastião Channel (São Paulo, Brazil), where the substrate is composed by a mixture of sand and rock fragments. Abiotic parameters such as salinity of interstitial water and sediment properties were used to characterize the environment. The polychaetes were well represented in the two sectors and their distribution was related with sediment type. The density of individuals and the number of taxa was higher at São Francisco, while the diversity and the evenness were higher at Engenho d’Água. This difference can be a consequence of organic enrichment caused by domestic input, and of the lower and more variable salinity at São Francisco. Due to these factors, a high density of opportunistic species, like Capitella capitata ssp., Scolelepis squamata, Laeonereis acuta and several oligochaetes, represented 75.5% of total abundance at this sector<br>Se estudiaron las comunidades bénticas de anélidos durante un periodo de un año (de agosto/95 a julio/96) en dos sectores de las playas Engenho d’Água and São Francisco, Canal de São Sebastião, donde el sustrato está compuesto por una mezcla de arena y fragmentos de roca. Se usaron parámetros abióticos como salidad del agua intersticial y propiedades de sedimento para caracterizar el ambiente. Los poliquetos estuvieron bien representados en los dos sectores y su distribución fue relacionada con el tiempo de sedimento. La densidad de los individuos y el número de táxones fuero mayores en São Francisco, mientras que la diversidad y la equidad fueron mayores en Engenho d’Água. Esta diferencia puede ser una consecueciade u enriquecimiento orgánico causado por una entrada doméstica y la salinidad más baja y variable en São Francisco. Debido a estos factores, la alta densidad de especiesoprtunistas como Capitella capitata ssp., Scolelepis squamata, Laeonereis acuta y varios oligochaetes, representó 75.5% de la abundancia local en ese sector
ISSN:0034-7744
2215-2075