IDENTIFICATION OF PRIORITY AREAS FOR MANA GEMENT OF THE FISH FAUNAS BIOLOGICAL DIVERSITY - A CASE-STUDY IN BAIXADA DE JACAREPAGUA, RIO-DE-JANEIRO, RJ, BRAZIL

A method to recognize environmentally sensitive areas for management o f the fish fauna is proposed. As a case study, the methodology was app lied to classify the aquatic environments of Baixada de Jacarepagua, R io de Janeiro, RJ, Brazil. Data about the fish assemblages of the regi on were obtained from existing studies and in samples carried monthly between March/1992 and January/1993. Local ecosystems were grouped int o lagoons (Laguna da Tijuca, Laguna de Marapendi and Laguna de Jacarep agua), rivers and wetlands. River sections were classified in headwate rs and lowlands. Wetlands were arranged into temporary or permanent sw amps. Statistical methods of association were applied to identify ecol ogical groups of species and to asses the affinity between the ecosyst ems. The environmental sensitivity was considered as the resilience ca pacity of the different systems and the importance of each ecosystem i n the conservation of endemic/endangered taxa and of biodiversity. In order to obtain the sensitivity, data on the richness of the region, a nd of each ecosystem, and the proportion of primary, eucenes, exclusiv e and endangered taxa were converted into sensitivity determinants' fa ctors (endemism, particularity, vulnerability, resilience, biodiversit y), calculated for each environment. The total sensibility of each hab itat was obtained using the multiatribute value theory (MVAT), produci ng scores that are positively associated with the degree of restrictio n that each environment presents to the establishment of human activit ies. In the Baixada de Jacarepagui region, the decreasing gradient of sensibility was represented by the following ordination: headwaters, t emporary swamps, lowlands, Laguna da Tijuca, permanent swamps, Laguna de Marapendi and Laguna de Jacarepagua.