Benthic macrofauna of the intertidal zone of Futuro Beach, Fortaleza, Ceará, Brazil

Abstract

A quali-quantitative analysis of intertidal benthic macrofauna of Futuro Beach, Fortaleza, Ceará State, Brazil, was accomplished. The analysis considered specific composition, density and zonation of organisms as a function of sediment temperature, salinity of percolation water, sediment particle-size, depth of ground water and rainfall. Samples were taken monthly, from May/1995 to February/1996. Transects with ten equidistant points were defined. A handle PVC cylindrical corer (Ø = 20 cm; h = 30 cm) was used to take triplicates at each point. Twenty-nine taxa were identified. The bivalve Donax striatus and the polychaete Scolelepis lefebvrei were dominants at three stations. The highest densities of organisms were found at E1. Probably, the morphodinamic state and the granulometric composition of the sediment influenced the differences in zonation patterns at three stations. The other environmental factors, such as the sediment temperature salinity of intersticial water, sediment particle-size and depth of ground water did not show significant influence on density and spatial distribution of macrofauna. Biotic factors such as adaptative morphological and functional characteristics may also have been determinants of such patterns.