Conservation status assessment of aquatic habitats within the Rhine floodplain using an index based on macrophytes (original) (raw)
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Science of The Total Environment, 2012
One objective of the European Union (EU)'s Water Framework Directive (WFD: Directive 2000/60/EC) is for all European surface waters to achieve 'good status' by 2015. In support of this objective, the EU has facilitated an intercalibration exercise to ensure harmonized definitions of the status of water bodies, reflecting the deviation of their properties (mainly biotic assemblages) from a minimally disturbed state, termed the "reference condition". One of the major challenges of the WFD has been to find common approaches for defining reference conditions and to define the level of anthropogenic intervention allowed in reference sites. In this paper we describe how river reference sites were selected in the Central-Baltic region of Europe. A list of pressure criteria was provided and 14 Member States (MSs) categorized each criterion according to the method (i.e. measured, field inspection, etc.) used for reference site screening. Additionally, reference landuse and water-chemistry thresholds were agreed among countries in order to base reference site selection on objective criteria. For land-use criteria, a reference threshold and a rejection threshold were established. Sites with all criteria below the reference threshold were considered to be reference sites; sites having most criteria below the reference threshold and only some parameters between the reference and rejection threshold were "possible reference sites". These sites were retained only after carefully checking the cumulative effects of the pressures using local expertise, and a posteriori water-chemistry evaluation was necessary. In general, the most widespread method for defining a reference site was the measurement of pressures, followed by field inspections and expert judgment. However, some major pressures (e.g. hydromorphological alteration) were evaluated in a number of different ways (e.g. measured, field inspection, expert judgment). Our meta-analyses reveal a need to reinforce standardization in the application of pressure criteria by Member States. The pressure criteria identified in this exercise should be refined and tested with biological data to help in the further validation of minimally disturbed sites (i.e. the WFD "reference condition") and to provide a firm foundation for ecological status assessment. This in turn would ensure that there is pan-European comparability when evaluating the achievement of environmental objectives.
• The aim was to establish a list of research needs for enhancing WFD implementation. • For ecological status, 10 research issues were identified. • The outcomes of SPI are likely to feed into the revision of the WFD. a b s t r a c t Keywords: Aquatic ecosystems Bioassessment Science-policy interface State-of-the-art WFD 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-compliant bioassessment methods. For rivers, special attention is required to assess the ecological impacts of hydromorphological alterations on biological communities, notably those affecting river continuity and riparian covering. Spatial extrapolation tools are needed in order to evaluate ecological status for water bodies for which no data are available. The need for more functional bioassessment tools as complements to usual WFD-compliant tools, and to connect clearly good ecological state, biodiversity and ecosystem services when implementing WFD were also identified as crucial issues.
Habitat Modelling of Rivers and Lakes in the Netherlands: An Ecosystem Approach
Canadian Water Resources Journal, 2003
In the Netherlands, ecological rehabilitation of rivers, lakes and wetlands has a high priority in water and nature management. As a consequence of recent EU policy and regulations, water managers have to take measures to improve the ecological functioning and quality of rivers and lakes towards 'good or high quality status'. To achieve those ecological objectives, measures must be taken to improve water quality and to restore the natural hydro-and morphodynamic conditions. To assess the effectiveness of the ecological rehabilitation measures, habitat modelling and evaluation methods can be of high importance. However, an ecosystem approach of applying habitat evaluation techniques is essential. In this paper, we describe the state-of-the-art of habitat modelling in the Netherlands and recent developments within the context of EU directives and policies. Due to these new developments, existing Dutch habitat modelling tools are currently being merged into one generic modelling framework. This framework is based on GIS and will contain ecological databases and links with hydraulic, hydrological, morphological and water quality models.
Ecological Indicators
This study deals with the application of macrozoobenthos-based biotic indices (BI) within the frame of the implementation of the European Water Framework Directive. More precisely, this study aimed at assessing the performance of five recently developed methodologies (BI) for the assessment of ecological quality status (EcoQ) in two semi-enclosed, sheltered coastal ecosystems and in one transitional water body situated along the Western French coast, namely Marennes-Oleron Bay, Arcachon Bay, and the Seine Estuary. This study showed that these five indices rarely agreed with each other, describing very different pictures of the overall EcoQ of the three study sites. This work also clearly underlined the limitations of these approaches, notably the dependency of most of these BI and the resulting EcoQ classifications on habitat characteristics, more particularly to natural levels of sediment silt-clay content and the location of stations in the subtidal or the intertidal. The implicat...