Diversity and space-time dynamics of fish assemblages in a coastal lagoon, western Atlantic

Abstract

The knowledge of the temporal and spatial dynamics in the composition of fish fauna makes it possible to identify patterns of occupation of ecosystems, providing a basis for evaluation and preservation of the local biodiversity. Monthly samplings were carried out at seven sites in a coastal lagoon, using a casting net, dip net and beach seine. A total of 4,110 individuals were collected, distributed in 23 families and 49 taxa of fish, with a predominance of Mugilliza, M.curema, Atherinellabrasiliensis, Micropogoniasfurnieri and Eucinostomusargenteus, corresponding to more than 80% total weight of all individuals caught. Regarding seasonality, greater abundances were recorded in fall, influenced by the high abundance of A.brasiliensis in this period. In addition to fall, this species was also abundant in summer. However, this pattern of dominance was different for the families Mugilidae and Gerreidae, with higher abundances in spring and summer, respectively. The highest abundances were found in the southern section of the lagoon, which are related to the high abundance of A.brasiliensis, M.liza and M.curema. In relation to the indices of average taxonomic distinctness and variation in the taxonomic distinctness, no significant differences were detected between the seasons of the year. Thus, the patterns of distribution and occurrence of fish in the lagoon were consistent with the patterns observed in Brazilian coastal lagoons and estuaries, as well as to the coastal shallow areas of the southeastern and southern regions.