Multiple determinants of community structure in shallow marsh habitats, Cape Fear River estuary, North Carolina, USA

Correspondence between environmental gradients and summer littoral fish assemblages in low salinity reaches of the Chesapeake Bay, USA

“…This coenocline is similar to patterns observed in other temperate and tropical zone coastal faunas (Weinstein et al 1980, Rogers et al 1984, Smith et al 1984, Felley 1987, Peterson & Ross 1991, Winemiller & Leslie 1992, and is characterized by a series of species supplements and replacements in successive downstream locations. Fish assemblages generally grade smoothly into each other with one notable exception; the freshwater interface is a boundary with a markedly increased rate of species turnover.…”

“…Previous estuarine studies differ in their estimation of the importance of salinity gradients to the distribution of estuarine fishes in mid-Atlantic waters (Weinstein et al 1980, Rogers et al 1984, Rozas & Hackney 1984, Bulger et al 1993). These disagreements have been attributed to seasonal alterations in large-scale gradients, and the integration of sequential recruitment of species throughout the year.…”

“…According to the generally accepted Gaussian model of assemblage structure, these fish populations may exhibit largely independent unimodal responses to complex environmental gradients resulting in a gradual species turnover known as a 'coenocline' (Gleason 1926;Whittaker 1967). Although environmental gradients (partic- ularly those correlated with salinity) clearly influence the distributional patterns of estuarine species along the mid-Atlantic coast (Boesch 1977, Weinstein et al 1980, the importance of environmental gradients to tidal freshwater assemblages is poorly understood. In a review contrasting tidal freshwater and salt marsh ecosystems, Odum (1988) concluded that while basic ecological structure and processes are the same at both ends of the estuarine gradient, significant differences exist in species diversity, assemblage structure, and in the patterns, rates and end products of many biogeochemical processes.…”

Distribuição espacial e abundância das assembléias de peixes no Parque Nacional da Lagoa do Peixe, Rio Grande do Sul, Brasil

“…Os grandes estuários apresentam um forte padrão longitudinal na taxa de troca de espécies desde a região de influên-cia marinha até a região límnica (WEINSTEIN et al 1980, PETERSON & ROSS 1991, WINEMILLER & LESLIE 1992, WAGNER & AUSTIN 1999. O estuário da Lagoa do Peixe, apesar de sua pequena proporção (35 Km 2 ) também apresentou um nítido gradiente de espé-cies entre a porção central da laguna até os setores norte e sul, com a substituição gradativa de espécies marinhas por espécies de água doce.…”

Environmental influences on distribution of four Sciaenidae species (Actinopterygii, Perciformes) in a tropical bay at Southeastern Brazil

“…The salinity has been mentioned as an environmental variable that influences the distribution of species (WAGNER & AUSTIN 1999, WHITFIELD 1999), although ATTRILL et al (1999 have reported against the interpretation of the role of the salinity because of the multi-colinearity with other environmental variables. WEINSTEIN et al (1980) pointed to salinity as the most important environmental variable to influence fish distribution in estuaries; but in more stable environment such as the Sepetiba Bay, the influence of salinity may be less remarkable. MARSHALL & ELLIOT (1998) reported that salinity in Humber estuary has a greater influence on the composition of the species than temperature.…”