Spatiotemporal variation in fish assemblage in a coastal lagoon without direct contact with the sea (southeastern Brazil)

Abstract

The Cabiunas Lagoon is a narrow water body that is perpendicular to the sea and isolated Before 1991, the sandbank was sometimes opened for a few days by local residents, but enters by limited groundwater seepage or by overtopping the sea barrier in storms. In 1998 National Park was established, including the Cabiunas Lagoon. Studies on the structure a the fish assemblage were performed between 1991 and 1994; we carried out one year (200 toring of the lagoon to identify spatiotemporal variations in the lagoon fish assemblage. T salinity content, and favoured oligohaline conditions and the increase of the aquatic macroph freshwater species dominance and reduction of the marine dependent and some coastal lag adapted to paralic ecosystems. Two freshwater, two coastal lagoon resident, and five mar which had been registered in the first studies (1991 and 1994), were not captured in the mean number of individuals (N m~2) decreased significantly (Kruskal-Wallis [KW] = 9.97 in biomass was found to be 80%. Species richness and diversity were also significantly r current conditions regarding specific composition along the longitudinal axis of the lagoo ture, salinity, and macrophyte coverage were important variables that influenced fish spatia and biomass.