Uso da taxocenose de peixes como indicadora de degradação ambiental no rio Paraíba do Sul, Rio de Janeiro, Brasil

Abstract

An adaptation of index of biotic integrity (IBI) was performed for the first time in

Ichthyofauna of the Ribeirão Taboão, Paraíba do Sul river basin, Mogi das Cruzes, SP

“…According to Karr (1981), Araújo (1998) and Araújo et al (2003) the analysis of the trophic structure of a given fish community is an interesting tool for evaluation of environmental degradation. Karr (1981) and Araújo (1998) cited that an area can be analyzed using three major criteria: the proportions of omnivorous and insectivorous species in the environment and the presence of top piscivores. Karr (1981) and Araújo (1998) mentioned a strong negative correlation between the proportion of omnivorous and insectivorous species in disturbed environments.…”

“…Karr (1981) and Araújo (1998) cited that an area can be analyzed using three major criteria: the proportions of omnivorous and insectivorous species in the environment and the presence of top piscivores. Karr (1981) and Araújo (1998) mentioned a strong negative correlation between the proportion of omnivorous and insectivorous species in disturbed environments. In our study we found a high abundance of omnivorous species, however we also found a high abundance of insectivorous species.…”

“…In our study we found a high abundance of omnivorous species, however we also found a high abundance of insectivorous species. Contradicting Karr (1981) and Araújo (1998) that mentioned also the absence of top piscivores in disturbed environments, we registered two piscivorous species at the study area, constituting the top of the trophic chain in their environments. This may indicate that the environment studied is not highly disturbed despite its proximity to a dense urban area.…”

“…Also, we found a high number of invertivorous species, that rely on the terrestrial environment as a source of food items, and the presence of top piscivorous species, At last, the study area comprises at least one new species, and potentially two other new species. Araújo (1998) and Araújo et al (2003) found that the lowest quality in fish assemblages occurred near cities that receive large amount of organic and industrial pollutants. Even though our data include a relatively low number of species probably due to limited sampling, our main results added to the close proximity of the study area to large urban centers show the need of improved public policies aiming at the conservation of its ichthyofauna, as well as programs of environmental education to raise the awareness of local settlers regarding their land and its fishes.…”

Utilização de índices ecológicos em assembléias de peixes como instrumento de avaliação da degradação ambiental em programas de monitoramento

“…Entre os mais frequentes fatores estudados em sistemas lóticos estão aqueles relacionados ao declínio da qualidade química da água (e.g., pH, oxigênio dissolvido, nitrato, amônia e fosfato), perda física do habitat (e.g., largura e integridade da vegetação ripária, tipos de substrato, e diversidade de mesohabitats), e declínio da integridade biótica (e.g., presença de espécies exóticas, tolerantes ou reofílicas) (Karr & Chu 1999). Karr (1981), Fausch et al (1990), Araújo (1998a, b), Bruschi Jr. et al (2000, Schiemer (2000) e Araújo et al (2003) utilizaram a comunidade de peixes como indicadores de qualidade da água em programas de monitoramento ambiental.…”