Ecologia de peixes em recifes artificiais de pneus instalados na costa do Estado do Ceará.

Abstract

The use of artificial reefs in the management of fishing resources is on the increase in countries whose populations rely heavily on the sea for food and employment and which display signs of overfishing of the main aquatic resources. Historical records show that artificial reefs were already in use over 300 years ago. In the United States they were introduced around 1830, and papers have been published on the subject in France and Australia since 1960. In Northeastern Brazil there is anecdotal evidence that artificial reefs have been built and employed by artisanal fishermen for generations. Some communities use timber while others use scrap materials such as old car parts and household appliances. The present study focuses on the fish populations observed at artificial reefs built with old tires off the municipalities of Itapipoca, Fortaleza and Beberibe (Ceará State) between 1995 and 2000. The sampling was performed by monitoring commercial catches from the reef location and by visual assessments performed by divers. Abundance data were obteined at two-month intervals. A total of 40 species belonging to 19 families were identified. Abundance (N), indices of diversity (H ), equitability (J ) and richness (S) were calculated. The study also proposes to classify reef-dwelling species according to behavioral pattern. There was a significant difference in H between the species found at the most recent reefs (Fortaleza) and those at the oldest (Beberibe). Equitability ranged between 85 and 92%. With regard to behavior, 16 of the 40 species observed remained in permanent contact with the structure, 9 species moved freely in and around it, while 5 were occasional free-swimming visitors.