Department of Biology, University of Aveiro, Portugal; CESAM - Centre for Environmental and Marine Studies, University of Aveiro, Portugal.
Department of Biology, University of Aveiro, Portugal; CESAM - Centre for Environmental and Marine Studies, University of Aveiro, Portugal.
Sci Total Environ. 2021 Feb 10;755(Pt 1):142534. doi: 10.1016/j.scitotenv.2020.142534. Epub 2020 Sep 29.
Benthic diatoms constitute keystone assemblages in riverine ecosystems, and their structure is used to support regulatory water quality assessment. However, no standard ecotoxicological tests exist using integrated responses of the benthic diatom assemblages. This work aimed to assess whether benthic diatom assemblages are responsive to different riverine contaminants through a previously developed rapid toxicity test, supporting future attempts towards its standardization and integration in both prospective and retrospective Environmental Risk Assessment (ERA) schemes. We selected two benthic diatoms assemblages likely responding similarly to pollution (similar IPS diatom index score), collected from two rivers in Northern-Central Portugal (sites: Palhal and Cabreia). Fresh whole diatom assemblages were exposed for 48 h to five model contaminants (glyphosate, imidacloprid, SDS, CuSO, and Pb). At the end of the test, changes induced by the exposures in overall yield and in the yield of each diatom genus were assessed. The assemblage collected at Palhal was invariably more responsive and sensitive than that collected at Cabreia, both considering overall and genus-specific yields, regardless of the tested contaminant. Achnanthes, Fragilaria and Navicula were the most responsive genus, regardless of the tested contaminant or assemblage. The distinct response profiles observed for the two assemblages to the same contaminants at the same concentration ranges suggest that using this test method to support prospective ERA is inadequate. However, the method can be an asset supporting retrospective ERA, as the responses seem to be shaped by the interplay of resilience drivers promoted by the local conditions, e.g. adaptive changes in assemblage structure.
底栖硅藻构成了河流生态系统中的关键组合，其结构被用于支持监管水质评估。然而，目前还没有使用底栖硅藻组合的综合反应来进行标准的生态毒理学测试。本研究旨在通过先前开发的快速毒性测试来评估底栖硅藻组合是否对不同的河流污染物有反应，从而支持未来在前瞻性和回顾性环境风险评估（ERA）计划中对其进行标准化和整合的尝试。我们选择了两个可能对污染有相似反应（相似的 IPS 硅藻指数得分）的底栖硅藻组合，从葡萄牙中北部的两条河流（Palhal 和 Cabreia 两个地点）收集。新鲜的完整硅藻组合在 48 小时内暴露于五种模型污染物（草甘膦、吡虫啉、SDS、CuSO 和 Pb）中。测试结束时，评估暴露对总产量和每个硅藻属产量的变化。Palhal 采集的组合始终比 Cabreia 采集的组合更有反应性和敏感性，无论是考虑总产量还是属特异性产量，无论测试的污染物如何。Achnanthes、Fragilaria 和 Navicula 是最有反应性的属，无论测试的污染物或组合如何。在相同的浓度范围内，两个组合对相同污染物的不同反应特征表明，使用这种测试方法来支持前瞻性 ERA 是不够的。然而，该方法可以作为支持回顾性 ERA 的资产，因为这些反应似乎是由当地条件下的弹性驱动因素的相互作用所塑造的，例如组合结构的适应性变化。
