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European Union Water Framework Directive (european + union_water_framework_directive)
Selected AbstractsDevelopment of fish-based methods for the assessment of ecological status in English and Welsh riversFISHERIES MANAGEMENT & ECOLOGY, Issue 6 2007R. A. A. NOBLE Abstract, This paper outlines the derivation of spatially-based models for fish-based assessment of the ecological status of rivers in England and Wales. The analysis highlights the key steps in the approach to develop such tools. For each step a number of alternative approaches were tested, and for each approach the major limitations and problems identified. This development of a multi-metric index in England and Wales indicated that, whilst the approach does provide promising results for the future, at this stage index development is constrained by limited data for some parts of the analysis. These mainly relate to coping with the zoogeographical influence of species distribution in a descriptive river typology, the availability of data for variables that adequately predict reference fish community types for impacted sites and availability of sufficient sites at a range of ecological conditions with which to test metrics and build an index that can be used to support implementation of the European Union Water Framework Directive. [source] Assessment of the ecological status of north-eastern Adriatic coastal waters (Istria, Croatia) using macroalgal assemblages for the European Union Water Framework DirectiveAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 1 2009Ljiljana Ive Abstract 1.Based on the inclusion of macroalgae in the European Union Water Framework Directive as quality elements for the evaluation of the ecological status of coastal waters, the suitability of one (Ecological Evaluation Index, EEI) of several previously proposed evaluation methods in the particular ecological conditions of the northern Adriatic Sea was tested. 2.The EEI was assessed for 10 locations (polluted and putatively pristine) scattered along 60,km of the western Istrian coast. The sampling was performed seasonally at 1 and 3,m depth by destructive (determination of species cover and biomass) and non-destructive (determination of species coverage using digital photography) methods. 3.When assessed at 1,m depth the spatial scale weighted EEI for the west Istrian coast was 8.1, corresponding to an ecological status class (ESC) value of high. However, data for 3,m depth gave a spatial EEI of 6.72 which corresponds to an ESC value of good. Regressions of the ratio of ecological state group I (ESG I, i.e. thick leathery, calcareous and crustose species) over total algal abundance with the pollution gradient (obtained using principal components analysis (PCA) ordination of environmental variables) were significant at 3,m but not at 1,m depth. This was due to the high abundance of ESG I macroalgae Corallina elongata and Cystoseira compressa at 1,m depth at polluted stations. Similar regressions were obtained using cover, biomass and coverage. 4.It is concluded that the EEI method may be suitable for the classification of coastal waters in the northern Adriatic only in certain cases. A better assessment of ecological status using this method would require more realistic estimations based on the inclusion of data from several sampling depths. As all three abundance measures (cover, biomass, coverage) gave similar results, coverage (using digital photography) is suggested as being a preferred measure owing to the rapidity of sampling at several depths and less time-consuming laboratory work. Copyright © 2008 John Wiley & Sons, Ltd. [source] An application of canonical correspondence analysis for developing ecological quality assessment metrics for river macrophytesFRESHWATER BIOLOGY, Issue 5 2005IAN DODKINS Summary 1. Aquatic macrophyte composition and abundance is required by the European Union's Water Framework Directive for determining ecological status. Five metrics were produced that can be combined to determine the deviation of aquatic macrophytes from reference conditions in Northern Ireland's rivers. 2. Species optima and niche breadths along silt, nitrate, pH, conductivity and dissolved oxygen gradients were generated from aquatic macrophyte and water quality surveys conducted at 273 sites throughout Northern Ireland using Canonical Correspondence Analysis (CCA). Five metric scores based on these environmental gradients were determined at new monitoring sites using the mean optima of the species occurring at the site, weighted by percentage cover and niche breadth of each species. 3. A preliminary reference network of 32 sites of high physico-chemical and hydromorphological quality, and representative of the range of river types in Northern Ireland, enabled reference metric scores to be produced for each river type. Five unimpacted and twenty impacted sites were used for testing the performance of the metrics. By subtracting reference metric scores from metric scores at a monitoring site measures of ecological impact could be determined along five different impact gradients. Metrics were also combined to give a measure of total ecological change. 4. The metrics system distinguished unimpacted from impacted sites and correctly identified 77% of the known impacts. The metrics distinguished different types of impact, e.g. silt and nitrate. 5. Aquatic macrophyte occurrence and abundance has high natural variability at a site, both temporally and spatially. This method was designed to be sensitive to ecological change whilst reducing noise caused by natural variation. [source] Understanding ,hot-spot' problems in catchments: the need for scale-sensitive measures and mechanisms to secure effective solutions for river management and conservationAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue S1 2010Malcolm Newson Abstract 1.Regulatory progress in controlling point sources of chemical river pollution has progressively thrown the attention of public policy towards anthropogenic physical impacts, many of which are scaled to the catchment via the runoff/sediment system. At the same time, concern over diffuse chemical pollution has reinforced ,catchment consciousness': land-use and land-management planning and control must be considered to conserve or restore river ecosystem integrity. 2.The scientific, political and legal elements of this scale change are, however, complex and uncertain: ,myths' abound. Landscape-scale consideration of ,pressures' suggests an unequal distribution of regulatory costs and benefits and large uncertainties in the evidence from a ,land-use hydrology' and fluvial geomorphology perspective. 3.,Hydrological connectivity' brings together a number of knowledge themes about catchment spatial organization which facilitate applying mitigation measures to much smaller areas, helping to offset uncertainty and reduce costs. 4.Instead of blanket ,remedies', more practical use is needed of process evidence from hydrology and fluvial geomorphology; this tends to suggest that ,hot-spots' dominate risks and impacts of factors such as leaching, surface flow generation and silt entrainment. 5.Set in a realistic policy framework, from strategic spatial planning to grant-aided best practice, a ,catchment acupuncture' approach to measures provides a cost-effective contribution to improving ecological status and may also increase resilience to the impacts of climate change. 6.The European Union's Water Framework Directive (WFD) encourages ,joined-up thinking' on this issue but it remains to be seen whether spatial scales, structures and concepts already enshrined in the WFD and the relevant UK national policies for land use and nature conservation can be exploited to permit the much-needed practical uptake of this new riparianism. Copyright © 2010 John Wiley & Sons, Ltd. [source] Alien and endemic flora at reference and non-reference sites in Mediterranean-type streams in PortugalAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 4 2007Francisca C. Aguiar Abstract 1.A comparison was made between a variety of alien and endemic plant species from 272 aquatic and riparian habitats in Portuguese Mediterranean-type streams in reference condition , i.e. near-natural river corridors , and non-reference condition. The objective was to detect differences in relative proportion and cover between these species groups. The differences in endemic and alien flora from siliceous and calcareous river types were also analysed. Environmental and human disturbance factors were related with the richness and cover of both species groups. 2.A total of 568 species were found, of which 44 were alien and 28 were endemic. Alien species were present at 91% of the surveyed locations, and were consistently more widespread at non-reference sites than at reference ones for both river types, with calcareous sites having a higher invasibility. Endemic species occurred at 45% of the sampling sites and displayed a significantly lower richness and cover than their alien counterparts. 3.Alien richness and cover were positively related to direct human disturbance within the river systems, and with floodplain uses such as urban occupation, intensive agriculture, and nutrient inputs. Endemic species also respond to anthropogenic variables, rather than to climatic and geographical ones, with richness and cover increasing as human impacts on fluvial systems and related floodplains decrease. 4.Comprehensive control of alien invasive species and the protection of endemic plant populations will require attempts at monitoring ecological river integrity, and the achievement of ,good ecological status' , one of the goals of the European Union's Water Framework Directive. Portuguese riparian areas must be managed in such a way as to protect the relatively few preserved riparian habitats by lowering the direct and indirect pressures in fluvial corridors and thus preventing future alien plant invasions. Copyright © 2006 John Wiley & Sons, Ltd. [source] | ||||||||||