a1 Postgraduate Programme in Biological Oceanography, Institute of Oceanography, Universidade de São Paulo, Praça do Oceanográfico 191, SP, Brazil, Zip code: 05508-120
a2 Postgraduate Programme in Zoology, Institute of Bioscience, Universidade Estadual Paulista, Botucatu, SP, Brazil, Zip code: 59625-900
a3 Postgraduate Programme in Ecology, Centre of Bioscience, Universidade Federal do Rio Grande do Norte, Praia de Mãe Luiza, s/n, Natal, RN, Brazil, Zip code: 59014-100
The temporal and spatial variation of Paralonchurus brasiliensis density (fish per m2) in relation to environmental factors was studied on the coasts of Ubatuba and Caraguatatuba, south-eastern Brazil. The fish were collected by shrimp fishery trawl on a monthly basis from January to December, 2002. Seven depths were previously established and for each one the temperature, salinity, organic matter content and grain size of the sediment (φ) was measured. The seasonal analysis of temperature and salinity indicated the presence of the water masses South Atlantic Central Water (SACW) and Coastal Waters (CW) acting in the study area. A total of 29,808 fish were collected during the study period. The highest densities were registered during the summer and autumn indicating an association with CW. The fish population moved to shallow depths during the intrusion of the cold water mass, SACW. The highest densities were registered in depths where the sediment composition ranged from fine sand to silt–clay. Thus, the temperature and type of the sediment are the main environmental factors which affect the spatial–temporal variation of P. brasiliensis density in south-eastern Brazil.
(Received August 18 2010)
(Accepted August 18 2011)
(Online publication November 11 2011)
c1 Correspondence should be addressed to: E.F.S. Costa, Postgraduate Programme in Biological Oceanography, Institute of Oceanography, Universidade de São Paulo, Praça do Oceanográfico 191, SP, Brazil, Zip code: 05508-120 email: firstname.lastname@example.org