von der Ohe Peter Carsten, Prüss Andrea, Schäfer Ralf Bernhard, Liess Matthias, de Deckere Eric, Brack Werner
Department of Effect-Directed Analysis, UFZ Helmholtz Centre for Environmental Research, Leipzig, Germany.
J Environ Monit. 2007 Sep;9(9):970-8. doi: 10.1039/b704699p. Epub 2007 Jul 30.
The European Water Framework Directive (WFD) requires the definition of near-natural reference conditions to determine the extent of water bodies' deviation from "good ecological status" caused by stress gradients. However, the classification of ecological quality depends on the assessment method applied and the stressor concerned. While assessment methods that are generally applicable would be favourable, many European countries employ the locally developed water quality metrics that assess the impact of organic pollution (including eutrophication) and the associated decrease in dissolved oxygen. These indices do not specifically address stress from organic toxicants, such as pesticides. The aim of this study was to examine the performance of presently used assessment methods to identify reference conditions of non-contaminated streams in five selected European river basins, covering the geographical region from Spain to Finland, as a crucial prerequisite to indicate toxic gradients. The analysis comprised the Belgium biotic index (BBI), the biological monitoring working party (BMWP) scoring system and the revised German saprobic index. For comparison, we included an adaptation of the recently developed SPEAR index. In two previous field studies, this metric highly correlated with measured pesticide gradients. In this study, SPEAR was the only indicator that was generally applicable to all monitoring data and capable of determining "high ecological status" of reference conditions in all basins. Thus, based upon previous and own results, the authors suggest the species at risk (SPEAR) index to be potentially useful as a European-wide index to address deviations from "good ecological status" due to organic toxicants and recommend it for consideration in integrated water-resource evaluations under the WFD.
欧洲水框架指令（WFD）要求定义近自然参考条件，以确定水体因压力梯度而偏离“良好生态状态”的程度。然而，生态质量的分类取决于所采用的评估方法和相关的压力源。虽然普遍适用的评估方法会更有利，但许多欧洲国家采用本地开发的水质指标来评估有机污染（包括富营养化）的影响以及溶解氧的相应减少。这些指标并未专门针对有机毒物（如农药）造成的压力。本研究的目的是检验目前使用的评估方法在确定五个选定欧洲流域未受污染溪流的参考条件方面的表现，这些流域覆盖了从西班牙到芬兰的地理区域，这是指示毒性梯度的关键前提。分析包括比利时生物指数（BBI）、生物监测工作组（BMWP）评分系统和修订后的德国污水生物指数。为作比较，我们纳入了最近开发的SPEAR指数的一种改编形式。在前两项实地研究中，该指标与测得的农药梯度高度相关。在本研究中，SPEAR是唯一普遍适用于所有监测数据且能够确定所有流域参考条件“高生态状态”的指标。因此，基于先前及自身的研究结果，作者建议将濒危物种（SPEAR）指数作为一项全欧洲范围的指数，用于解决因有机毒物导致的偏离“良好生态状态”的问题，并建议在水框架指令下的综合水资源评估中予以考虑。
