Efeitos de um processo de engorda de praia sobre a comunidade meiofaunística da zona entre-marés da praia de Candeias (Jaboatão dos Guararapes – PE)

Abstract

Marine erosion, which is characterized by the retreat of the coastline against the sea, promotes a significant loss of habitat for organisms inhabiting the intertidal zone. At various points along the coast of Pernambuco this erosion is already perceived at moderate to severe levels,and some actions have already been carried out to contain the retreat from the beach line. Recently, a process of containment of the marine erosion in the state of Pernambuco was carried out, aiming first at the most affected areas. This action provided, along a 5.5 km stretch,the widening of the sand strip of the beaches of Barra de Jangadas, Candeias and Piedade by a beach nourishment process. The sedimentary recomposition of these beaches was made through sand dredged from the continental shelf fromadepthof13m.Thisstudyanalyzedtheecologicalsuccessionof meiofaunal organisms (from 0.044 mm to 0.5 mm in size), and the sediments inwhich they live, in the beach of Candeias (Jaboatão dos Guararapes, PE) before and after a process of beach nourishment for up to 90 days after the process.These animals have a biology adapted to the interstitial environment, and can vary according to the variation of the nature and size of the grains. The collections were performed before the beach nourishment, 1 day after, 7, 15, 30, 60 and 90 days after sediment deposition, in the infralittoral and in the intertidal zone. The material was performed in the laboratory through routine techniques for the study of meiofauna, which was identified at high taxonomic levels. This work investigated the effects of this process on the meio fauna community of the beach and its ecological succession, dueto its close relationship with the sediments and their characteristics.It was verified that immediately aftert he process of beach nourishment the sediments were modified, and also the structure of the meio fauna community that colonizes them. This has undergone several changes in its structure, both in species richness and inabundance. Statistical tests showed a tendency to stabilize or even stabilize the community structure in a pattern that is significantly similar to the meiofauna originally existing on the beach. Thus, the results point to a possibility of using meiofauna in environmental biomonitoring programs for coastal engineering actions.