Centre for the Research and Technology of Agro-Environment and Biological Sciences, Vila Real, Portugal.
Centre for the Research and Technology of Agro-Environment and Biological Sciences, Vila Real, Portugal; Department of Engineering, University of Trás-os-Montes and Alto Douro (UTAD), Ap. 1013, 5001-801 Vial Real, Portugal.
Sci Total Environ. 2017 Dec 1;599-600:217-226. doi: 10.1016/j.scitotenv.2017.04.196. Epub 2017 May 3.
The purpose of this study was to relate the severity of histopathological changes in fish gills with changes in metal concentrations of freshwater samples, and to use the relationships as premature warnings of impairment in aquatic fauna populations. The investigated species were the native barbel (Luciobarbus bocagei) and boga (Pseudochondrostoma sp.), and the introduced trout (Oncorhynchus mykiss), collected from 6 northern Portuguese rivers in a total of 249 individuals. The sampling sites have been linked to different ecological status by the official authorities. The sampling has been repeated 4 times to cover different hydrologic and environmental conditions. The analyzed metals were aluminum, arsenic, cadmium, cobalt, chromium, copper, manganese, nickel, lead and zinc. For each fish, 30 filaments of a gill arch were observed in a light microscope, and the histopathological changes evaluated according to a 6-degree gradation scale that combines the extent and severity of each lesion. The relationships between the histopathological and the chemical results were investigated by the non-parametric Goodman Kruskal gamma correlation and Partial Least Squares regression (PLS). The statistical results highlighted the importance of filament epithelium proliferation (FEP) as key biomarker to the toxicity of sub lethal concentrations of metals, because FEP was significantly correlated with all analyzed metals and explained through PLS regression by concentration changes of Cu, Zn, Mn, Cr and As. A refined regression analysis, where histopathological data on the 3 species were processed in separate, revealed that FEP severity is especially sensitive to changes in metal concentrations in boga. Thus, monitoring studies on the ecological status of northern Portuguese rivers would benefit in time and cost if FEP is used as biomarker and boga as species. Naturally, the option for this species depends on the availability of boga individuals along the stream reaches selected for the monitoring programs.
本研究旨在将鱼类鳃组织的组织病理学变化严重程度与淡水样本中金属浓度的变化联系起来，并将这些关系作为水生动物种群受损的早期预警。研究的物种是本地的巴贝尔（Luciobarbus bocagei）和博加（Pseudochondrostoma sp.），以及引入的虹鳟（Oncorhynchus mykiss），它们分别从葡萄牙北部的 6 条河流中采集，共采集了 249 条个体。采样点已被官方机构与不同的生态状况联系起来。采样已经重复了 4 次，以涵盖不同的水文和环境条件。分析的金属包括铝、砷、镉、钴、铬、铜、锰、镍、铅和锌。对于每一条鱼，在光学显微镜下观察 30 个鳃弓的鳃丝，并根据一个 6 度分级量表评估组织病理学变化，该量表结合了每种病变的程度和严重程度。通过非参数 Goodman Kruskal gamma 相关性和偏最小二乘回归（PLS）研究了组织病理学和化学结果之间的关系。统计结果突出了纤维上皮增生（FEP）作为亚致死浓度金属毒性的关键生物标志物的重要性，因为 FEP 与所有分析的金属显著相关，并通过 PLS 回归解释为 Cu、Zn、Mn、Cr 和 As 浓度的变化。一项更精细的回归分析，将 3 种鱼类的组织病理学数据分别进行处理，结果表明 FEP 的严重程度对博加金属浓度的变化特别敏感。因此，如果将 FEP 用作生物标志物，将博加作为物种，对葡萄牙北部河流生态状况的监测研究将在时间和成本上受益。当然，这种选择取决于监测计划中选择的溪流段是否有博加个体。
