Towards holistic assessment of the functioning of ecosystems under the Water Framework Directive (original) (raw)
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Ecological Indicators, 2015
The European Water Framework Directive (WFD) represents a transformation of the guidelines for water quality assessment and monitoring across all EU Member States. At present, it is widely accepted that the WFD requires holistic and multidisciplinary ecological approaches by integrating multiple lines of evidence. Within the scope of the WFD, the scientific community identified clear opportunities to take advantage of an ecotoxicological line of evidence. In this context, ecotoxicological tools, namely biomarkers and bioassays, were proposed to contribute to the integration of the chemical and biological indicators, and thus to provide an overall insight into the quality of a water body. More than one decade after the publication of the WFD, we reviewed the studies that have attempted to integrate ecotoxicological tools in the assessment of surface water bodies. For this purpose, we reviewed studies providing an ecological water status assessment through more conventional community based approaches, in which biomarkers and/or bioassays were also applied to complement the evaluation. Overall, from our review emerges that studies at community level appear suitable for assessing the ecological quality of water bodies, whereas the bioassays/biomarkers are especially useful as early warning systems and to investigate the causes of ecological impairment, allowing a better understanding of the cause-effect-relationships. In this sense, community level responses and biomarkers/bioassays seem to be clearly complementary, reinforcing the need of combining the approaches of different disciplines to achieve the best evaluation of ecosystem communities' health.
Ecological Indicators, 2012
The European Water Framework Directive (WFD) has as its objective the establishment of a framework for the protection of continental, groundwater and surface, transitional, and coastal water. The phytoplankton is one of the biological quality elements established for determining the ecological status within the Directive. Phytoplankton biomass, composition and abundance, together with frequency of blooms, are the metrics to be assessed according to the WFD. For the Mediterranean coastal water only biomass (chlorophyll a) has been intercalibrated by the Mediterranean Geographical Intercalibration Group. In the present contribution, a multimetric index PHYMED for ecological classification of coastal water bodies in Valencia Region is developed based on biomass and phytoplankton community composition. First, a conceptual model was established to develop a system of indicators based on the composition of the phytoplankton community. Formulating the model required a preliminary analysis of the existing correlations between the parameters related to the phytoplankton community composition and the variations in the pressure indicators in each coastal water body. After discarding those variables which did not readily allow a distinction between coastal water bodies to be discerned four phytoplankton variables were selected to constitute the PHYMED index. Reference conditions were determined based on the analysis of pressures and impacts and supplemented by a thorough territorial analysis. To verify that this index responded well to the varying ranges in pressure, a statistically significant correlation was confirmed to exist between the index and the phosphorus values. The results obtained from this index were compared with those derived using chlorophyll a finding that the existing deviations presently arising from the use of chlorophyll a as an ecological status indicator can be corrected with the proposed multimetric index.
Ecological Indicators, 2014
ABSTRACT Few researchers have assessed the important management questions regarding the sensitivity of indicators of aquatic ecosystem condition and the specificity with which anthropogenic development activities are described. Furthermore, there is limited knowledge as to the potential of structural and functional indicators to generate complementary knowledge about ecological condition that can be used to inform watershed management. We assessed 20 metrics of ecological structure and function at 19 riverine sites across the Red River watershed in the summer of 2010 using a gradient approach to test predictions that: (1) indicator sensitivity would vary with the specificity at which landscape development is described (i.e., coarse - land use [e.g., agriculture], medium - specific human activities [e.g., crop cultivation] and fine management practices [e.g., crop rotation]); and (2) structural and functional indicators respond to different types and specificity of anthropogenic development. Evaluation of indicators revealed that indicator sensitivity was frequently greater for assessment of specific human activities (i.e., wastewater treatment, crop cultivation or livestock production), than for broad land-use categories (i.e., agriculture or urban). Structural and functional indicators were often associated with different types of anthropogenic development suggesting additive rather than redundant assessment information. Structural indicators were almost exclusively associated with crop cultivation and agricultural land cover. In contrast, functional indicators were generally associated with gradients of wastewater treatment and urban land cover. Our results demonstrate that aquatic ecosystem assessment programs would benefit from considering the specific anthropogenic development activity to be assessed and managed in order to evaluate and select the most sensitive indicators of stream condition. Furthermore, combined use of structural and functional indicators in aquatic monitoring program appears to improve detection of anthropogenic impacts in a multiple stressor environment.
Challenges in the development and use of ecological indicators
Ecological indicators, 2001
Ecological indicators can be used to assess the condition of the environment, to provide an early warning signal of changes in the environment, or to diagnose the cause of an environmental problem. Ideally the suite of indicators should represent key information about structure, function, and composition of the ecological system. Three concerns hamper the use of ecological indicators as a resource management tool. (1) Monitoring programs often depend on a small number of indicators and fail to consider the full complexity of the ecological system. (2) Choice of ecological indicators is confounded in management programs that have vague long-term goals and objectives. (3) Management and monitoring programs often lack scientific rigor because of their failure to use a defined protocol for identifying ecological indicators. Thus, ecological indicators need to capture the complexities of the ecosystem yet remain simple enough to be easily and routinely monitored. Ecological indicators should meet the following criteria: be easily measured, be sensitive to stresses on the system, respond to stress in a predictable manner, be anticipatory, predict changes that can be averted by management actions, be integrative, have a known response to disturbances, anthropogenic stresses, and changes over time, and have low variability in response. The challenge is to derive a manageable set of indicators that together meet these criteria. Published by Elsevier Science Ltd.
The Science of the total environment, 2014
The Water Framework Directive (WFD) is now well established as the key management imperative in river basins across Europe. However, there remain significant concerns with the way WFD is implemented and there is now a need for water managers and scientists to communicate better in order to find solutions to these concerns. To address this, a Science-Policy Interface (SPI) activity was launched in 2010 led by Directorate-General for Research and Innovation and Onema (the French national agency for water and aquatic ecosystems), which provided an interactive forum to connect scientists and WFD end-users. One major aim of the SPI activity was to establish a list of the most crucial research and development needs for enhancing WFD implementation. This paper synthesises the recommendations from this event highlighting 10 priority issues relating to ecological status. For lakes, temporary streams and transitional and coastal waters, WFD implementation still suffers from a lack of WFD-comp...
Progress in Botany, 2016
Aquatic plants and benthic algae have long been used as indicators for nutrient enrichment in lakes and streams. Evaluations of the performance of indices calculated from species assemblages of aquatic plants and algae are generally based on correlations with water nutrient concentrations. We argue that this is a misinterpretation, because water chemistry is both cause and effect: higher nutrient concentrations may cause enhanced plant and algal growth and change their assemblages, but plants and benthic algae also remove nutrients from the water. Additionally, biotic interactions blur water chemistry-aquatic plant relationships. We suggest that indices can be improved by relating biotic responses to quantifiable causal stressors, such as nutrient loading, instead of using water chemistry for performance evaluation of the indices. In addition, a tiered approach, i.e. the use of simpler indices for getting an overview and of sophisticated methods in doubtful cases, could avoid unnecessary costs and efforts while giving important monitoring and management information.