Spatial pattern of benthic macrofauna in a sub tropical shelf, Sao Sebastiao Channel, southeastern Brazil

Abstract

ABSTRACT. Diversity and community organization of the benthic macrofauna were investigated along the São Sebastião Channel, northern coast of São Paulo State, Brazil, and related to sedimentary variables and organic load. These important outstanding soft bottom benthic habitats are characterized by their close proximity to sources of human impact. Sampling was undertaken seasonally, using a Van Veen grab (0.1 m 2 ) in 15 oceanographic stations, from November 1993 to August 1994. A total of 392 species were recorded and polychaetes completed nearly 50% of the fauna. Twenty three species were most numerous and frequent and comprised the baseline pool for the area. Sites were classified with respect to sediments in three site-groupings according to Arasaki et al. (2004). The finest-sediment site-group had significantly fewer species than coarser site-groups. The stations locate at the south opening and in the axis of the channel presented sediments with organic matter predominantly of marine origin, indicating the flow of open sea waters across the channel. These places showed also higher values of diversity and species richness. The site-group located along the insular side and in the channel north mouth, stood out for the significantly higher density. Although its relative small area the channel presented species richness similar to that found in the adjacent inner continental shelf. Comparisons between channel and adjacent shelf habitats are addressed in the light of ecological data. Keywords: diversity, macrofauna, continental shelf, São Sebastião Channel, Brazil, South Atlantic Ocean.Aspectos ecológicos de la macrofauna bentónica del Canal de São Sebastião, sudeste de Brasil RESUMEN. Se estudió la organización y diversidad de la comunidad macrobentónica de fondos blandos del canal de São Sebastião, costa norte del Estado de São Paulo, Brazil, relacionándolo con variables sedimentológicas y carga orgánica del sedimento. Estos fondos marinos importantes para especies bentónicas se caracterizan por encontrarse próximos a fuentes de impacto antrópico. El muestreo se desarrolló estacionalmente a lo largo de un año, en 15 estaciones oceanográficas, con una draga Van Veen (0.1 m 2 ), desde noviembre de 1993 hasta agosto de 1994. Se identificó un total de 392 especies, correspondiendo los poliquetos aprox. al 50% de la fauna. De este total, 23 especies fueron las más abundantes y frecuentes. Las estaciones fueron clasificadas según el sedimento en tres grupos de acuerdo con Arasaki et al. (2004). El grupo de estaciones caracterizado por sedimentos finos presentó significativamente menos especies que los otros dos grupos. Las estaciones localizadas en el extremo sur del canal y en su eje longitudinal presentaron sedimentos con materia orgánica predominantemente de origen marino, reflejando el flujo de aguas del océano abierto a través del canal. Estas estaciones mostraron también mayores valores de diversidad y riqueza de especies. Por otro lado, el grupo de estaciones localizado del lado insular y en la boca norte del...

Abundance and spatial-temporal distribution of the shrimp Xiphopenaeus kroyeri (Decapoda: Penaeidae): an exploited species in southeast Brazil

“…This close association was also observed by Pires-Vanin et al (2013), on the north coast of São Paulo, where the seasonality of SACW affected macrofauna benthic invertebrates distribution patterns. Furthermore, Dall et al (1990) and Costa and Fransozo (2004) stated that temperature is a major determinant parameter in the temporal distribution of organisms, especially for penaeid shrimp.…”

How marine upwelling influences the distribution of Artemesia longinaris (Decapoda: Penaeoidea)?

“…The deepest area (100 m) is influenced by high sedimentation, while shallower regions are more influenced by cold water (De Léo & Pires-Vanin, 2006). According to Pires-Vanin et al (2013) changes on water temperature and salinity affect the distribution pattern of the macrofauna of benthonic invertebrates. Additionally, Dall et al (1990) and affirm that the temperature is considered one of the main determinant parameters in the temporal distribution of organisms, mainly for penaeid shrimps.…”

Inventory of the marine soft bottom macrofauna of São Sebastião Channel, southeastern Brazilian continental shelf

“…For detailed studies about structure of benthic communities in the SSC see Muniz and Pires (1999;2000), Pires-Vanin (2008); for functional ecology data see Arasaki et al (2004) and Pires-Vanin et al (2013) and for ecosystem functioning Venturini et al (2011;2012).…”