Abstract：
The aim of this study was to characterize an aquatic system of Santa Fe province (Argentina) receiving wastewater from agro-industrial activities (mainly dairy) by in situ assessment (fauna mortality, physicochemical, microbiological, and pesticide residues measurement), and ecotoxicity bioassays on amphibian tadpoles. Water and sediment samples were obtained from the Los Troncos Stream (LTS), previous to the confluence with the \"San Carlos\" drainage channel (SCC), and from the SCC. Biological parameters (mortality and sublethal biomarkers) were used to evaluate ecotoxicity during 10-day exposure of Rhinella arenarum tadpoles to LTS and SCC samples. Nine pesticides were detected in both LTS and SCC. Chemical and biochemical oxygen demand, ammonia, and coliform count recorded in SCC greatly exceeded limits for aquatic life protection. At SCC and LTS after the confluence with SCC, numerous dying and dead aquatic turtles (Phrynops hilarii) were recorded. In the ecotoxicity assessment, no mortality of tadpoles was observed in LTS treatment, whereas total mortality (100%) was observed in SCC treatments in dilution higher than 50% of water and sediment. For SCC, median lethal concentration and the 95% confidence limits was 18.30% (14.71-22.77) at 24 h; lowest-observed and no-observed effect concentrations were 12.5% and 6.25%, respectively. Oxidative stress and neurotoxicity were observed in tadpoles exposed to 25% SCC dilution treatment. In addition, there was a large genotoxic effect (micronuclei test) in all sublethal SCC dilution treatments (6.25%, 12.5%, and 25%). These results alert about the high environmental quality deterioration and high ecotoxicity for aquatic fauna of aquatic ecosystems affected by agro-industrial wastewater. PRACTITIONER POINTS: Great mortality of turtles was observed in a basin with a high load of agro-industrial wastewater. San Carlos Channel (SCC), where effluents are spilled, is environmentally deteriorated. The water-sediment matrix of SCC caused 100% lethality in tadpoles. SCC dilutions caused neurotoxicity, oxidative stress, and genotoxicity on tadpoles.
摘要：
这项研究的目的是通过原位评估（动物死亡率，物理化学,微生物,和农药残留测量)，和两栖动物t的生态毒性生物测定。水和沉积物样品是从LosTroncos溪流（LTS）获得的，在与“圣卡洛斯”排水通道(SCC)汇合之前，来自SCC。使用生物学参数（死亡率和亚致死性生物标志物）来评估红藻t暴露于LTS和SCC样品10天期间的生态毒性。在LTS和SCC中均检测到9种农药。化学和生化需氧量，氨,SCC中记录的大肠杆菌数量大大超过了水生生物保护的限制。在与SCC汇合后的SCC和LTS处，记录了许多死亡和死亡的水龟（Phrynopshilarii）。在生态毒性评估中，LTS治疗中未观察到t死亡，而在稀释度高于50%的水和沉积物的SCC治疗中观察到总死亡率(100%)。对于SCC，24h时的中位致死浓度和95％置信限为18.30％（14.71-22.77）；最低观察到和未观察到的效应浓度分别为12.5％和6.25％，分别。在暴露于25％SCC稀释处理的t中观察到氧化应激和神经毒性。此外,在所有亚致死SCC稀释治疗中都有很大的基因毒性作用(微核试验)(6.25%，12.5%,和25%）。这些结果警告了受农业工业废水影响的水生生态系统的水生动物群的高环境质量恶化和高生态毒性。实践要点：在农业工业废水负荷较高的流域中观察到海龟的死亡率很高。圣卡洛斯频道（SCC），废水溢出的地方，环境恶化。SCC的水沉积物基质在t中引起100％的致死性。SCC稀释导致神经毒性，氧化应激，和对t的遗传毒性。
