Effects of the proximity from an industrial plant on fish assemblages in the rio Paraíba do Sul, southeastern Brazil

Abstract

This work aims to analyze changes in the fish assemblages along a longitudinal reaches of the rio Paraíba do Sul, one of the most used Brazilian aquatic systems, to assess the river "health" and to identify eventual recovery trends. Standardized monthly samplings were carried out at six sites, from October 1997 to September 1999, using casting, sieves, seine and gill nets. Three zones were searched: upstream (Z I), downstream (Z III) and nearby the source of pollution (Z II). Three univariate distribution methods were used: ABC (abundance-biomass curves), K-dominance curves, and geometric class's distribution. Additionally, cluster analysis was applied to detect eventual patterns. The ABC and K-dominance curves showed Z II with evident indication of stress in both yearly cycles, followed by Z III and Z I. Few rare species and absence of common species in Z I, presence of common and abundant species, mainly opportunist, in Z II, and the highest number of rare species in Z III, was the overall pattern showed by geometric class. Number of fish was higher at Z II, while number of species did no change significantly among zones. Cluster analysis separate Z II samples from Z I and III. All the three univariate methods showed evident signals of stress at Z II, which showed indication of organic enrichment as expressed in the high abundance of common species, although physicochemical variables (ammonia, nitrogen, total phosphorous and DBO) have increased slightly from Z1 to Z III. A lesser stress condition was shown at the downstream zone (Z III), indicating the river recovery capacity. The use of biological indicators in this study proved to be a better tool to assess non-point sources pollution when compared to traditional physicochemical measurements.Objetiva-se no presente trabalho, analisar mudanças nas assembléias de peixes ao longo de um trecho longitudinal do rio Paraíba do Sul, um dos sistemas aquáticos mais usados do Brasil, para avaliar a "saúde" do rio e identificar eventuais tendências de recuperação. Amostragens mensais foram realizadas em seis locais, de outubro de 1997 a setembro de 1999, utilizando redes de espera, tarrafas, peneiras e picaré. Foram atribuídas três zonas para avaliar as assembléias de peixes: Z II (complexo industrial da cidade de Volta Redonda -fonte da poluição), Z I (montante do complexo industrial) e Z III (jusante do complexo industrial). Três métodos univariados foram usados: ABC (curvas de abundância-biomassa), curvas de K-dominância, e distribuição por classes geométricas. Adicionalmente, foram aplicadas análises de agrupamento para verificar padrões de distribuição das espécies. A curva ABC e a curva de K-dominância indicaram maior estresse para a Z II, em ambos os ciclos anuais seguido pelas Z III e I. A classe geométrica apresentou um padrão de poucas espécies raras e ausência de espécies comuns para a Z I, presença de espécies comuns e abundância de espécies oportunistas para a Z II, e maior número de espécies raras na Z III. O número de indivíduos foi maior na Zona II, enqu...

Distribution of guppies Poecilia reticulata (Peters, 1860) and Phalloceros caudimaculatus (Hensel, 1868) along a polluted stretch of the Paraíba do Sul River, Brazil

“…Similar distribution patterns for these two species were also found by Araújo et al (2001), with P. reticulata being the most abundant fish species at Z2, while P. caudimaculatus, ranked as the third most abundant species at Z3. The use of deteriorated areas by opportunistic fish species has been reported by several workers (Hughes and Gammon, 1987;Soto-Galera et al, 1998;Harris and Silveira, 1999;Pinto et al, 2006b;Pinto and Araújo, 2007). They have reported that the limitation of natural resources decreased specialist species which are replaced by opportunistic ones, since the latter can use the available resources and cope with the harsh environmental conditions of deteriorated areas.…”

“…An amount of 160 m 3 /s is pumped from the study area for hydroelectric power and water supply purposes, increasing water quality concerns. Effects of habitat and water deterioration have been described by Pfeiffer et al, 1986;Carvalho and Torres, 2002;Pinto et al, 2006b, who reported large numbers of textile, chemical and food industries, and the presence of the major siderurgic industrial plant at Volta Redonda as the main source of alteration of the system. Additionally, pesticides and herbicides form agricultural activities contribute to add diffuse pollution over the extent of the river, with negative effects on the water quality (Radambrasil, 1983).…”

“…The Paraíba do Sul River receives high amounts of organic and industrial effluents that directly affect the ichthyofauna by decreasing fish abundance and limiting distribution of more sensitive species (Araújo et al, 2003;Pinto et al, 2006b;Pinto and Araújo, 2007). An amount of 160 m 3 /s is pumped from the study area for hydroelectric power and water supply purposes, increasing water quality concerns.…”

“…In this scope, P. reticulata and P. caudimaculatus have been reported as indicators of poor water condition due to their ability to thrive in harsh environmental conditions (Araújo, 1983). Both species have been recorded along the Paraíba do Sul River mainly in more polluted stretches (Araújo et al, 2001;Teixeira et al, 2005;Pinto et al, 2006b;Pinto and Araújo, 2007). On the other hand, fish condition indicates health and can be influenced by environmental conditions (Vila-Gispert and Moreno-Amichi, 2001).…”

Ecology of Phallotorynus pankalos (Cyprinodontiformes: Poeciliidae) in a first-order stream of the upper Paraná Basin

“…Some have treated morphological description and comparison of the sexes (Gusmão & Pavanelli, 1996). Others have suggested that some species can be used to assess habitat integrity (Bozzetti & Schulz, 2004;Cunico et al, 2006;Ferreira & Casatti, 2006;Pinto et al, 2006;Vieira & Shibatta, 2007), mainly Poecilia reticulata and Phalloceros caudimaculatus.…”