Densidade e biomassa do marisco (Anamalocardia flexuosa) no banco de extração da praia de Mangue Seco, Igarassu-PE

Abstract

The beach of Mangue Seco, in the state of Pernambuco, is a place with a large number of ecosystems and is mainly characterized by the capture of the species Anomalocardia flexuosa. Delineation of the region that has noticeable physical and morphodynamic characteristics was considered. First, the effects of the surrounding waters and the proximity of the beach line were considered, so three main strata of location were evaluated (edge, inland coast and inland sea), as well as secondary strata with latitudinal and longitudinal divisions. In the division of the Mangue Seco bank it was possible to differentiate, mainly, four strata of location, nevertheless, it is emphasized that zoning must be a dynamic process. The beach of Mangue Seco has a traditional and very old activity of catching A. fleuxosa, however a type of dredger was introduced as fishing gear in the bank and its predominance is recent. The dredge is used mainly with two types of mesh and although the mesh larger than 20 mm captures a percentage of individuals larger than 20 mm than the 16 mm mesh, both have a higher proportion of retention of individuals than smaller than 20 mm , which denotes care for its use. Additionally, this means of capture can impact the malacofauna that is not the target of the fishing, causing mortality even in case of escape due to physical damages in the shell. In fact, this is worrying because in the results evaluated most molluscs seem to overlap in terms of distribution. There is concern about mollusks that are not commercially caught, but for the target species, works warn that the lengths of the molluscs must already be fully compromised, which generates the hypothesis of over fishing for growth, but it is verified that in the present situation there is not potentially signs of overfishing, but that the incentive to increase fishing mortality should not be considered.