Sciades herzbergii oxidative stress biomarkers: an in situ study of an estuarine ecosystem (São Marcos' Bay, Maranhão, Brazil)

Abstract

A B S T R A C TIn order to study the effects of environmental contamination on wild fish, sites were sampled in São Marcos' Bay. The first is located near the ALUMAR/ALCOA port, a potentially contaminated area. The second, located near the Coqueiro beach, was used as a reference area. The activity of antioxidant defence catalase (CAT) and glutathione S-transferase (GST) in S. herzbergii was compared with the biometric data and gonadosomatic index (GSI). The result showed that GSI decreased significantly in females (p<0.05) at the contaminated site. The activity of CAT was higher in fish caught at the contaminated site. A significant difference was observed in GST activity in the liver of S. herzbergii in the comparison between fish from the contaminated site and those from the reference site (p<0.05). GSI provides new insights into the nature of the detoxification response in this catfish species because it is not correlated with the enzymes at the potentially contaminated site. We are, therefore, in a position to suggest that the elevated GST/CAT activity might well be related to the reproduction of the animals at the reference site but not at the potentially contaminated site. If that be the case, one may conclude that GST/CAT and GSI are useful biomarkers of aquatic contamination. R E S U M OO objetivo desse trabalho foi estudar os efeitos da contaminação ambiental em peixes amostrados em dois locais da Baía de São Marcos. O primeiro ponto está localizado próximo ao porto da ALUMAR/ALCOA, considerado como uma área potencialmente contaminada. O segundo ponto, situado na praia do Coqueiro, foi usado como uma área de referência. Dados da atividade da enzima de defesa antioxidante catalase (CAT) e da glutationa S-transferase (GST) em S. herzbergii foram comparados com os dados biométricos e o índice gonadossomático (GSI). Resultados mostraram que o GSI diminuiu significativamente em fêmeas (p <0.05) no local contaminado. A atividade da CAT foi mais alta nos peixes do local contaminado. Uma diferença significativa foi observada na atividade de GST de S. herzbergii no local contaminado e no local de referência (p <0.05). GSI possibilitou uma nova abordagem quanto à natureza da resposta de destoxificação nessa espécie de bagre porque este índice não apresentou correlação com as enzimas no local potencialmente contaminado, mas apresentou no local de referência. Assim, sugere-se que a boa correlação da GST/CAT e GSI poderia estar relacionada à reprodução dos animais no local de referência, mas não no local potencialmente contaminado. Se esse for o caso, pode-se concluir que GST/CAT e GSI podem ser utilizados como bons biomarcadores para avaliar contaminação aquática.

A histopathological and biometric comparison between catfish (Pisces, Ariidae) from a harbor and a protected area, Brazil

“…All heavy metals concentrations (Al, Cd, Pb, Cr, Fe, Hg) in water collected from the potentially contaminated area were significantly higher than water from the reference area. Previous studies on sediment and water in the harbor area showed significantly higher levels of mercury and chrome, which confirms that the port area in São Marcos Bay is a site with high exposure risks for some contaminants [3,7,8]. Öztürk et al [12] have determined the level of heavy metals in various tissues of the Cyprinus carpio species and they reported that cadmium, chromium, nickel, and lead concentrations exceeded the tolerable values provided by international institutions.…”

“…Biomarker analysis has been shown to be adequate for ascertaining the toxic effects of a given toxicant [3]. Biomarkers have been defined by measurable modifications at the molecular, biochemical, cellular, physiological, and behavioral levels, revealing the exposure of a given organism to xenobiotics [4].…”

“…In São Luís Island (São Marcos Bay, Maranhão), the catfish Sciades herzbergii , a benthic fish common to Brazil coastal areas, has been identified as a model species for investigating the effects of contamination in estuarine systems [3]. Bagre bagre , another catfish, resides in both contaminated and clean estuarine environments around the São Marcos Bay.…”

Biomarkers in Catfish Sciades herzbergii (Teleostei: Ariidae) from Polluted and Non-polluted Areas (São Marcos’ Bay, Northeastern Brazil)

“…In the last decade, chemical contamination of that bay due to sewage discharge and the nutrient runoff from pesticides, industrial waste, as well as the incorrect use of resources have all aggravated environmental impact and thus led to an increasing threat to the health of aquatic organisms. The main pollutants, such as heavy metals, derive from industrial activities through their respective marine terminals (Itaqui, VALE, and ALUMAR/ALCOA) located in São Marcos' Bay [7]. This has adverse effects, particularly when contaminants are not or only slightly decomposable, exhibit a high biological effectiveness, possess a high potential for accumulation, and influence each other in a synergistic or additive way in the case of multiple contaminants [8].…”

The use of biomarkers to assess the health of aquatic ecosystems in Brazil: a review

“…It is relevant to note the lack of studies published about the Midwestern region (one single study) and Northern region (three studies) despite the existence of two important biomes of Brazil in these regions-the Pantanal and Amazon Rainforest, respectively. According to Carvalho-Neta and Abreu-Silva (2010) and Montes et al (2010), the lack of studies using biomarkers as predictors of aquatic health in these regions, and also in the Northeast, indicates the need of biomonitoring studies that might estimate the potential effects suffered by native species.…”