Classification and assessment of degradation in European running waters (original) (raw)
Related papers
Fisheries Management and Ecology, 2010
A fish-based assessment method was developed to estimate the ecological status of boreal rivers. Electric fishing data were collected from 902 rapids, together with information on the land use, channel modification and water chemistry. Discriminant function analysis was used to select fish variables that most correctly classified the undisturbed reference sites and human impacted sites into exact classes. The relationship between the level of human alteration and fish metrics was examined. Five metrics were selected for the index: the number of fish species, proportion of sensitive species, proportion of tolerant species, density of cyprinid individuals and the density of age-0+ salmonids. The value for each metric (between 0 and 1) was calculated according to a point estimate for classical probability. The index is used to estimate the ecological classification of rivers according to the EU Water Framework Directive. K E Y W O R D S : bioassessment, environmental impact, environmental quality, Finnish fish index, freshwater fish community, index of biological integrity.
Journal of Applied Ecology, 2006
1The need for sensitive biological measures of aquatic ecosystem integrity applicable at large spatial scales has been highlighted by the implementation of the European Water Framework Directive. Using fish communities as indicators of habitat quality in rivers, we developed a multi-metric index to test our capacity to (i) correctly model a variety of metrics based on assemblage structure and functions, and (ii) discriminate between the effects of natural vs. human-induced environmental variability at a continental scale.2Information was collected for 5252 sites distributed among 1843 European rivers. Data included variables on fish assemblage structure, local environmental variables, sampling strategy and a river basin classification based on native fish fauna similarities accounting for regional effects on local assemblage structure. Fifty-eight metrics reflecting different aspects of fish assemblage structure and function were selected from the available literature and tested for their potential to indicate habitat degradation.3To quantify possible deviation from a ‘reference condition’ for any given site, we first established and validated statistical models describing metric responses to natural environmental variability in the absence of any significant human disturbance. We considered that the residual distributions of these models described the response range of each metric, whatever the natural environmental variability. After testing the sensitivity of these residuals to a gradient of human disturbance, we finally selected 10 metrics that were combined to obtain a European fish assemblage index. We demonstrated that (i) when considering only minimally disturbed sites the index remains invariant, regardless of environmental variability, and (ii) the index shows a significant negative linear response to a gradient of human disturbance.4Synthesis and applications. In this reference condition modelling approach, by including a more complete description of environmental variability at both local and regional scales it was possible to develop a novel fish biotic index transferable between catchments at the European scale. The use of functional metrics based on biological attributes of species instead of metrics based on species themselves reduced the index sensitivity to the variability of fish fauna across different biogeographical areas.The need for sensitive biological measures of aquatic ecosystem integrity applicable at large spatial scales has been highlighted by the implementation of the European Water Framework Directive. Using fish communities as indicators of habitat quality in rivers, we developed a multi-metric index to test our capacity to (i) correctly model a variety of metrics based on assemblage structure and functions, and (ii) discriminate between the effects of natural vs. human-induced environmental variability at a continental scale.Information was collected for 5252 sites distributed among 1843 European rivers. Data included variables on fish assemblage structure, local environmental variables, sampling strategy and a river basin classification based on native fish fauna similarities accounting for regional effects on local assemblage structure. Fifty-eight metrics reflecting different aspects of fish assemblage structure and function were selected from the available literature and tested for their potential to indicate habitat degradation.To quantify possible deviation from a ‘reference condition’ for any given site, we first established and validated statistical models describing metric responses to natural environmental variability in the absence of any significant human disturbance. We considered that the residual distributions of these models described the response range of each metric, whatever the natural environmental variability. After testing the sensitivity of these residuals to a gradient of human disturbance, we finally selected 10 metrics that were combined to obtain a European fish assemblage index. We demonstrated that (i) when considering only minimally disturbed sites the index remains invariant, regardless of environmental variability, and (ii) the index shows a significant negative linear response to a gradient of human disturbance.Synthesis and applications. In this reference condition modelling approach, by including a more complete description of environmental variability at both local and regional scales it was possible to develop a novel fish biotic index transferable between catchments at the European scale. The use of functional metrics based on biological attributes of species instead of metrics based on species themselves reduced the index sensitivity to the variability of fish fauna across different biogeographical areas.
Abstract When developing a decision tool as a fish index it is crucial to document its performance,in relation to its goals. An important requirementof the WFD is that the newly developed European Fish Index (EFI) can distinguish between a (nearly) pristine and disturbed status. Also the position of EFI with respect to existing national or regional fish indexes should be clear as some of them offer a long time series. Finally, comparison of the EFI with respect to other possible approaches gives insight inits relative merits and shortcomings. To realize this evaluation, the central idea of this chapter is to think the fish index as a laboratory test to detect whether or not a site is disturbed. This analogy allows expressing the performance in terms of the detection capacity (sensitivity and specificity, impacted and non-
Fish-based methods for assessing European running waters: a synthesis
Fisheries Management and Ecology, 2007
Abstract The European Union, Water Framework Directive (WFD) requires monitoring of riverine fish fauna. When the WFD came into force in 2000, most of the EU member states did not have fish-based assessment methods compliant to WFD requirements. Therefore, the objectives of FAME (http://fame.boku.ac.at), a project under the fifth R&D Framework Programme of the European Commission were to develop, evaluate and implement a standardised fish-based method for assessing the ecological status of European running waters. This paper synthesises the outputs of FAME and defines future research needs. Two different methodologies were used: the so-called spatially based modelling and the site-specific modelling, the latter leading to the European Fish Index (EFI). The advantage of the EFI is that, despite being a single index, it is applicable to a wide range of environmental conditions across Europe precluding the need for inter-calibration. The EFI will support the WFD towards harmonised/standardised assessment and management of running waters in Europe, thus enabling comparative analyses of the ecological status of running waters across Europe.
Fisheries Management and Ecology, 2007
The objective was to develop spatially based (type-specific) methods to assess the ecological status of European rivers according to the EU Water Framework Directive. Some 15 000 samples from about 8000 sites were pre-classified within a five-tiered classification system based on hydromorphological and physico-chemical pressures. The pre-classification was used to identify reference conditions and to calibrate the assessment methods. Clustering reference sites based on relative species composition resulted in 60 fish assemblage types within 11 of the ecoregions under study. Discriminant function analyses (DFAs) were employed to identify environmental parameters characterising fish assemblage types; altitude, river slope, wetted width, mean air temperature and distance from source were the principal predictors. These environmental parameters were used to assign impacted sites with altered fish assemblage composition to the reference fish assemblage type. Metrics (fish assemblage descriptors) responding to human pressures were selected based on correlation and DFAs. Assessment methods were developed for 43 fish assemblage types. Metrics based on individual sentinel species were more often used in type-specific methods than metrics related to reproduction, habitat and feeding. Metrics based on long-distance migrants and potamodromous species were more sensitive to human pressures than overall composition metrics, e.g. total number of species. Only some of the tested metrics showed pressure-specific responses, i.e. reacted to one type of pressure but not to others. Insectivorous, intolerant and lithophilic species exclusively responded (decreased) to chemical and hydromorphological pressures in 14-19%. Omnivorous species was the only metric type that showed a consistent reaction (increase) to continuum disruptions in 25% of the cases. Accuracy of methods based on cross-validation with pre-classification varied between 47% and 98% (mean 81%) when contrasting calibration data set (class 1 and 2) with degraded sites (class 3, 4 and 5).
Development and validation of a fish-based index for the assessment of 'river health' in France
Freshwater Biology, 2002
1. In Europe, water policy is currently undergoing considerable change as emphasised by the recent European Water Framework Directive (WFD), which requires the restoration and maintenance of 'healthy' aquatic ecosystems by the assessment of their hydromorphological, chemical and biological characteristics. If the requirements of the WFD are to be met, effective biological tools are needed to measure the 'health' of rivers at scales large enough to be useful for management. These tools need to be ecologically based, efficient, rapid and applicable in different ecological regions. Among potential indicators, fish assemblages are of particular interest because of their ability to integrate environmental variability at different spatial scales. To meet the goals of the WFD, the French Water Agencies and the Ministry of the Environment initiated a research programme to develop a fish-based index that would be applicable nationwide. 2. A variety of metrics based on occurrence and abundance data and reflecting different aspects of the fish assemblage structure and function were selected from available literature and for their potential to indicate degradation. 3. Logistic and multiple linear regression procedures were applied, using an initial data set of 650 reference sites fairly evenly distributed across French rivers and defined by some easily measured regional and local characteristics, to elaborate the simplest possible response model that adequately explained the observed patterns of each metric for a given site. 4. Models obtained for each metric were validated using two independent data sets of 88 reference sites and 88 disturbed sites. These procedures allowed us to select the most effective metrics in discriminating between reference and disturbed sites.
Using fish to assess environmental disturbance of Swedish lakes and streams — a preliminary approach
Internationale Vereinigung für theoretische und angewandte Limnologie: Verhandlungen, 2000
A variety of measures and indices based on fish community data have been used to assess environmental degradation and biotic integrity (HuET 1954, HAWKES 1975, I<ARR 1981, ANGERMEIER & I<ARR 1986, Ai'PELBERG et al. 1989, DEGERMAN & LINGDELL 1993, MINNS et al. 1994). Common to most such measures is the need for knowledge about fish communities in a 'pristine' situation. When 'before impact' data are lacking or information is scattered, the 'pristine' situation has to be predicted. For the index o f biotic integriry, the reference situation is generally set a priori by a competent fish ecologist (I<ARR 1981), although the criteria for metrics related to species richness also have been set in relation to habitat size (see FAUSCH et al. 1984, 1990 for reviews). MINNS et al. (1994) used an alternative approach, using a wide range of habitat types that were assumed to comprise habitats that represented both degraded as well as acceptable reference habi...
2006
The need for sensitive biological measures of aquatic ecosystem integrity applicable at large spatial scales has been highlighted by the implementation of the European Water Framework Directive. Using fish communities as indicators of habitat quality in rivers, we developed a multi-metric index to test our capacity to (i) correctly model a variety of metrics based on assemblage structure and functions, and (ii) discriminate between the effects of natural vs. human-induced environmental variability at a continental scale. 2. Information was collected for 5252 sites distributed among 1843 European rivers. Data included variables on fish assemblage structure, local environmental variables, sampling strategy and a river basin classification based on native fish fauna similarities accounting for regional effects on local assemblage structure. Fifty-eight metrics reflecting different aspects of fish assemblage structure and function were selected from the available literature and tested for their potential to indicate habitat degradation. 3. To quantify possible deviation from a 'reference condition' for any given site, we first established and validated statistical models describing metric responses to natural environmental variability in the absence of any significant human disturbance. We considered that the residual distributions of these models described the response range of each metric, whatever the natural environmental variability. After testing the sensitivity of these residuals to a gradient of human disturbance, we finally selected 10 metrics that were combined to obtain a European fish assemblage index. We demonstrated that (i) when considering only minimally disturbed sites the index remains invariant, regardless of environmental variability, and (ii) the index shows a significant negative linear response to a gradient of human disturbance. 4. Synthesis and applications . In this reference condition modelling approach, by including a more complete description of environmental variability at both local and regional scales it was possible to develop a novel fish biotic index transferable between catchments at the European scale. The use of functional metrics based on biological attributes of species instead of metrics based on species themselves reduced the index sensitivity to the variability of fish fauna across different biogeographical areas.
Toward an Integrated Assessment of the Ecological and Chemical Status of European River Basins
Integrated Environmental Assessment and Management, 2009
This is 1 of 12 papers prepared by participants attending the workshop ''Risk Assessment in European River Basins-State of the Art and Future Challenges'' held in Liepzig, Germany on 12-14 November 2007. The meeting was organized within the framework of the European Commission's Coordination Action RISKBASE program. The objective of RISKBASE is to review and synthesize the outcome of European Commission FP4-FP6 projects, and other major initiatives, related to integrated risk assessment-based management of the water/ sediment/soil environment at the river basin scale.