Departamento de Biologia, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal.
Centro de Estudos do Ambiente e do Mar (CESAM), Universidade de Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal.
Environ Sci Pollut Res Int. 2020 Aug;27(24):30789-30799. doi: 10.1007/s11356-020-09362-3. Epub 2020 May 30.
Enzymatic biomarkers, especially oxidative-stress enzymes, are useful for assessing the status of aquatic environments. The present study used biochemical markers determined in nervous, gill, and liver tissues of Sciades herzbergii, concomitantly with analyses of trace metals in the tissues and bottom sediment, to evaluate environmental quality in Amazon estuaries. The study was conducted from March 2014 to February 2016 in two areas: Caeté estuary in Bragança, state of Pará, which is relatively unimpacted; and São Marcos Bay, next to a harbor in São Luís, state of Maranhão. In the laboratory, the fish were weighed (g) and measured (cm). Fragments of the gills, the brain, and the liver were biochemically analyzed, and the metal contents in the brain, the liver, and the muscle tissues were determined. Turbidity was significantly higher (p < 0.05) in São Marcos than in Bragança. Specimens of S. herzbergii were smaller in São Marcos, and aluminum, iron, nickel, copper, cadmium, and mercury levels were higher in bottom sediment (p < 0.05) collected at this location. Fish from São Marcos contained significantly higher (p < 0.05) concentrations of aluminum, iron, and cadmium in the muscle tissue than fish from Bragança. In addition, fish from São Marcos had significantly higher concentrations of nickel in both the nervous and hepatic tissues. Only fish from São Marcos contained measurable concentrations of mercury in the liver and muscle. Fish from Bragança had copper concentrations in the liver significantly different from those captured at São Marcos (p < 0.05). The activities of gill glutathione S-transferases (GSTs) (F = 6.62; df = 1, 16; p < 0.05) and liver CAT (F = 10.22; df = 1, 16; p < 0.05) were higher in fish from São Marcos. However, ChE in brain tissues and lipid peroxidation (LPO) in the gills and liver did not differ significantly between fish from both areas. The physico-chemical conditions of the water and the concentrations of metals found in sediment and biological tissues, together with the biochemical responses of S. herzbergii in the study areas, indicate that this species is still tolerant to adverse environmental conditions, but the presence of metals is a risk to the health of fish, mainly to fish from São Marcos, especially if chronically exposed.
酶生物标志物，尤其是氧化应激酶，可用于评估水生环境的状况。本研究使用神经、鳃和肝脏组织中的生化标志物，同时分析组织和底泥中的痕量金属，以评估亚马逊河口的环境质量。该研究于 2014 年 3 月至 2016 年 2 月在两个地区进行：布拉干萨州的卡埃特河口，相对未受影响；以及圣路易斯附近的圣马科斯湾。在实验室中，对鱼进行称重（克）和测量（厘米）。对鳃、脑和肝组织进行生化分析，并测定脑、肝和肌肉组织中的金属含量。圣马科斯湾的浊度明显高于布拉干萨湾（p<0.05）。圣马科斯湾的 S. herzbergii 标本较小，该地点采集的底泥中铝、铁、镍、铜、镉和汞含量较高（p<0.05）。圣马科斯湾鱼肌肉组织中铝、铁和镉浓度明显高于布拉干萨湾鱼（p<0.05）。此外，圣马科斯湾鱼的神经和肝组织中镍浓度明显较高。只有圣马科斯湾的鱼肝和肌肉中才测出汞的浓度。布拉干萨湾鱼肝铜浓度与圣马科斯湾鱼有显著差异（p<0.05）。鳃谷胱甘肽 S-转移酶（GSTs）（F=6.62；df=1,16；p<0.05）和肝 CAT（F=10.22；df=1,16；p<0.05）活性较高。然而，两个地区鱼脑中的 ChE 和鳃及肝中的脂质过氧化（LPO）没有显著差异。研究区水的理化条件和沉积物及生物组织中金属的浓度，以及 S. herzbergii 的生化反应，表明该物种仍然能耐受不利的环境条件，但金属的存在对鱼类健康构成威胁，特别是对圣马科斯湾的鱼类，尤其是在长期暴露的情况下。
