A Comparative Study Of Intertidal Molluscan Communities In Sandy Beaches, São Sebastião Channel, São Paulo State, Brazil

The aim of this work was to study the molluscan communities in two intertidal environments and their relationship with selected environmental variables. The study areas are located along São Francisco and Engenho d'Agua beaches (São Sebastião Channel, São Paulo State, Brazil). These sites are structurally similar with sediments of coarse sand and pebbles that facilitate settlement of molluscan species. The area was subdivided into low, intermediate and high intertidal levels where the samples were taken. Temperature, salinity, grain size, organic matter, and calcium carbonate content were analyzed as environmental variables. The high species diversity recorded in the study sites was due to the occurrence of organisms on consolidated and unconsolidated substrates. However, differences in the specific composition of the two areas were associated with local differences in sediment constituents and the presence of urban waste water in São Francisco. In general, few species were common to both sites, with higher richness and number of individuals in Engenho d'Água. Differences in environmental variables and in species distribution between the two areas were indicated by Canonical Correspondence Analysis, which also revealed that grain size, salinity and calcium carbonate content played a more important role in species distribution than did the organic matter content.65191103Amaral, A.C.Z., Ecologia e contribuição dos anelídeos poliquetos para a biomassa bêntica da zona entremarés, no litoral notre do Estado de São Paulo (1979) Boletim do Instituto Oceanográfico, 28, pp. 1-52Morgado, E.H., Lopes, P.P., Belúcio, L.F., Leite, F.P.P., Ferreira, C.P., Composition and distribution of the intertidal macrofauna of sandy beaches on São Paulo coast. Anais II Simpósio de Ecossistemas da Costa Sul e Sudeste Brasileira - Estmmração, Função e Manejo (1990) Publ. ACIESP, S. Paulo, 3 (71), pp. 258-279Bemvenuti, C.E., Capitoli, R.R., Gianuca, N.M., Estudo de ecologia bêntica da região estuarial da Lagoa dos Patos. II. Distribuição quantitativa dos macrobentos infralitoral (1978) Atlântica, 3, pp. 23-32Borzone, C.A., Distribución de la malacofauna en el infralitoral de una playa arenosa expuesta del sur del Brasil (1994) Revista Investigacion Cientifica Serie Ciencia Marina, U.A.B.C.S., 5 (NUMERO ESPECIAL 1), pp. 23-36. , COLACMARCapitoli, R.R., Benvenuti, C.E., Gianuca, N.M., Estudos de ecologia bêntica na região estuarial da Lagoa dos Patos. I. As comunidades bentônicas (1978) Atlântica, 3, pp. 5-22Corbisier, T.N., Benthic macrofauna of sandy intertidal zone at Santos estuarine system, São Paulo, Brasil (1991) Boletim do Instituto Oceanográfico, 39, pp. 1-13Dahl, E., Some aspects of the ecology and zonation of the fauna on sandy beaches (1953) Oikos, 4, pp. 1-27Dexter, D.M., Community structure of intertidal sandy beaches in New South Wales, Australia (1983) Sandy beaches as ecosystems, pp. 461-472. , A. McLachlan and T. Erasmus, eds. Port Elizabeth, South Africa. Dr. W. Junk Publ., The HagueTemporal and spatial variability in the community structure of the fauna of four sandy beaches in south-eastern New South Wales (1984) Aust. J. Mar. Freshw. Res., 35, pp. 663-672Drouin, G., Himmelman, J.H., Béland, P., Impact of tidal salinity fluctuations on echinoderm and mollusc populations (1985) Can. J. Zool., 63, pp. 1377-1387Furtado, V.V., Sedimentação quaternária no Canal de São Sebastião (1995) Publicação Especial do Instituto Oceanográfico, 11, pp. 27-35Gianuca, N.M., A preliminary account of the ecology of sandy beaches in Southern Brazil (1983) Sandy beaches as ecosystems, pp. 413-419. , A. McLachlan and T. Erasmus, eds. Port Elizabeth, South Africa. Dr. W. Junk Publ., The HagueGray, J.S., Animal-sediment relatioships (1974) Oceanogr. Mar. Biol. Ann. Rev., 12, pp. 223-261Hill, M.O., (1979) Twinspan - A Fortran program for arranging multivariate data in a ordered two-way table by classification of the individual and attributes, , Cornnel Univ., Ithaca, New York. 318 pKnox, G.A., The role of polychaetes in benthic soft-bottom communities (1977) Essays on polychaetous annelida in memory of Dra. Olga Hartman, pp. 547-609. , D. B. Reish and K. Fauchauld, eds. Allan Hancock Fdn., Los Angeles, CaliforniaKovach, W.L., A multivariate statistics package (1986) MVSP Plus, ver. 2.0aKrebs, C.J., (1989) Ecological methodology, , Harper Collins, New York. 654 pMacArthur, R.H., (1972) Geografical ecology, , Harper & Row, New York. 269 pMcCune, B., Mefford, M.J., (1995) PC-ORD. Multivariate analysis of ecological data, ver. 2.0, , MjM Software Design, Gleneden Beach, Oregon. 106 pMcLachlan, A., Sandy beach ecology - A review (1983) Sandy beaches as ecosystems, pp. 321-380. , A. McLachlan and T. Erasmus, eds. Port Elizabeth, South Africa. Dr. W. Junk Publ., The HagueBate, G.C., Sandy beach ecology - Workshop report (1983) Sandy beaches as ecosystems, pp. 569-572. , A. McLachlan and T. Erasmus, eds. Port Elizabeth, South Africa. Dr. W. Junk Publ., The HagueWooldridge, T., Dye, A.H., The ecology of sandy beaches in Southern Africa (1981) Suid-Afrikaanse Tydskrif vir Dierkunde, 16 (4), pp. 219-231Migotto, A.E., Tiago, C.G., Magalhães, A.R.M., Malacofauna marinha da região costeira do Canal de São Sebastião, SP, Brasil: Gastropoda, Bivalvia, Polyplacophora e Escaphopoda (1993) Boletim do Instituto Oceanográfico, 41 (1-2), pp. 13-27Morgado, E.H., (1988) Anelídeos poliquetos do sublitoral da região de Ubatuba-SP, compreendida entre as ilhas Anchieta e Vitória, , Ph.D. Thesis. Universidade Estadual de Campinas, Campinas-SP, Brasil. 181 pAmaral, A.C.Z., Nonato, E.F., Salvador, L.B., Intertidal sandy beaches Polychaetes of São Sebastião Island, southern Brazil (1994) Mem. Mus. natl. Hist. nat., Paris, 162, pp. 485-492Narchi, W., Aspectos ecológicos e adaptativos de alguns bivalves do litoral paulista (1974) Papéis Avulsos de Zoologia, 27 (19), pp. 235-269Omena, E.P., Amaral, A.C.Z., Distribuição espacial de polychaeta (Annelida) em diferentes ambientes entremarés de praias de São Sebastião (SP) (1997) Oecologia Brasiliensis: Ecologia de Praias Arenosas do Litoral Brasileiro, Rio de Janeiro, 3, pp. 183-196Rios, E.C., (1994) Seashells of Brazil. 2nd ed., , Fundação Universidade do Rio Grande, Rio Grande. 492 pSouza, J.R.B., (1991) Zonação e variação temporal da macrofauna bentônica da praia arenosa de Barrancos - PR, , M.S. Thesis, Universidade Estadual do Paraná, Curitiba-PR, Brasil. 67 pWilkinson, L., (1990) SYSTAT: The system for statistcs, , SYSTAT, Inc., Evanston, Illinois. 677 pWoodin, S.A., Disturbance and community structure in a shallow water sand flat (1981) Ecology, 62, pp. 1052-1066Zar, J.H., (1984) Biostatistical analysis. 2nd ed., , Prentice-Hall, New Jersey. 718