Show simple item record Garcia, Alexandre Miranda Hoeinghaus, David Joseph Vieira Sobrinho, João Paes Winemiller, Kirk 2012-11-08T13:57:17Z 2012-11-08T13:57:17Z 2007
dc.identifier.citation GARCIA, Alexandre Miranda et al. Isotopic variation of fishes in freshwater and estuarine zones of a large subtropical coastal lagoon. Estuarine, Coastal and Shelf Science, v. 73, p. 399-408, 2007. Disponível em: <>. Acesso em: 18 out. 2012. pt_BR
dc.description.abstract We used stable C and N isotope ratios of tissues from 29 fish species from a large subtropical lagoon in southern Brazil to examine spatial variability in isotopic composition and vertical trophic structure across freshwater and estuarine habitats. Nitrogen isotope ratios indicated a smooth gradation in trophic positions among species, with most fishes occupying the secondary and tertiary consumer level. Fish assemblages showed a significant shift in their carbon isotopic signatures between freshwater and estuarine sites. Depleted carbon signatures (from _24.7& to _17.8&) were found in freshwater, whereas more enriched signatures (from _19.1& to _12.3&) were obtained within the estuarine zone downstream. Based on our survey of the C3 and C4 plants and isotopic values for phytoplankton and benthic microalgae reported for ecosystems elsewhere, we hypothesized that the observed d13C differences in the fish assemblage between freshwater and estuarine sites is due to a shift from assimilating organic matter ultimately derived from C3 freshwater marsh vegetation and phytoplankton at the freshwater site (d13C ranging from _25& to _19&), to C4 salt-marsh (e.g. Spartina) and widgeon grass (Ruppia maritima), benthic microalgae and marine phytoplankton at the estuarine sites (from _18& to _12&). Our results suggested that fish assemblages are generally supported by autochthonous primary production. Freshwater fishes that likely were displaced downstream into the estuary during periods of high freshwater discharge had depleted d13C values that were characteristic of the upper lagoon. These results suggest that spatial foodweb subsidies can occur within the lagoon. pt_BR
dc.language.iso eng pt_BR
dc.rights open access pt_BR
dc.subject Brazil pt_BR
dc.subject Estuary pt_BR
dc.subject Freshwater discharge pt_BR
dc.subject Food webs pt_BR
dc.subject Neotropical fishes pt_BR
dc.title Isotopic variation of fishes in freshwater and estuarine zones of a large subtropical coastal lagoon pt_BR
dc.type article pt_BR

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