Demersal fi sh fauna from areas with different levels of human occupation, in Paranaguá estuary

Abstract

Direct and indirect relationships between assemblages of  fi sh and human impacts on estuaries reinforce the choice  of this taxonomic group as a biological indicator. This study had as objective to identify alterations on  fi sh fauna structure  of two bays located in Paranaguá estuary, Paraná State, with different levels of human occupation. The abundance  curves of ranked  fi sh species showed higher dominance in the ones derived from catch aggregates of  Cathorops spixii,  Pomadasys corvinaeformis and  Genidens genidens . The K-dominance curves showed smaller diversity in Paranaguá  Bay in August and December, while in February and June the diversity was smaller in Laranjeiras Bay. The abundance  and biomass curves (ABC) showed con fi gurations of polluted and non-polluted areas in Laranjeiras and Paranaguá in  different periods of the year, but their inversions cannot be related to levels of environmental degradation. In the whole  sampling period, neither the ordination analysis (MDS) nor the similarity analysis (ANOSIM) indicated signi fi cant  differences in the  fi sh fauna composition of both areas. Because of the inexistence of a de fi ned pattern, no trend related to  environmental quality was identified.