Ecological Quality Standards Research Articles

Water quality deterioration remains a major stressor for macroinvertebrate, diatom and fish communities in German rivers

About 60 % of Europe's rivers fail to meet ecological quality standards derived from biological criteria. The causes are manifold, but recent reports suggest a dominant role of hydro-morphological and water quality-related stressors. Yet, in particular micropollutants and hydrological stressors often tend to be underrepresented in multiple-stressor studies. Using monitoring data from four Federal States in Germany, this study investigated the effects of 19 stressor variables from six stressor groups (nutrients, salt ions, dissolved oxygen/water temperature, mixture toxicity of 51 micropollutants, hydrological alteration and morphological habitat quality) on three biological assemblages (fishes, macroinvertebrates, benthic diatoms). Biological effects were analyzed for 35 community metrics and quantified using Random Forest (RF) analyses to put the stressor groups into a hierarchical context. To compare metric responses, metrics were grouped into categories reflecting important characteristics of biological communities, such as sensitivity, functional traits, diversity and community composition as well as composite indices that integrate several metrics into one single index (e.g., ecological quality class).Water quality-related stressors – but not micropollutants – turned out to dominate the responses of all assemblages. In contrast, the effects of hydro-morphological stressors were less pronounced and stronger for hydrological stressors than for morphological stressors. Explained variances of RF models ranged 23–64 % for macroinvertebrates, 16–40 % for benthic diatoms and 18–48 % for fishes. Despite a high variability of responses across assemblages and stressor groups, sensitivity metrics tended to reveal stronger responses to individual stressors and a higher explained variance in RF models than composite indices. The results of this study suggest that (physico-chemical) water quality deterioration continues to impact biological assemblages in many German rivers, despite the extensive progress in wastewater treatment during the past decades. To detect water quality deterioration, monitoring schemes need to target relevant physico-chemical stressors and micropollutants. Furthermore, monitoring needs to integrate measures of hydrological alteration (e.g., flow magnitude and dynamics). At present, hydro-morphological surveys rarely address the degree of hydrological alteration. In order to achieve a good ecological status, river restoration and management needs to address both water quality-related and hydro-morphological stressors. Restricting analyses to just one single organism group (e.g., macroinvertebrates) or only selected metrics (e.g., ecological quality class) may hamper stressor identification and its hierarchical classification and, thus may mislead river management.

Refinement of the NISECI ecological index reference conditions for Italian freshwater fish communities in the eastern Emilia-Romagna region

Following the Water Framework Directive 2000/60/CE (WFD), each member state of the European Union must monitor compliance of its rivers with ecological quality standards through biological quality indicators. The New Italian Index of the Ecological State of Fish Communities (NISECI) was developed in 2017 for the assessment of fish communities, as directed by the WFD in Italian freshwater habitats. According to the WFD, the general reference conditions (GRCs) of NISECI must be refined on a regional scale through new calculation of its metrics and sub-metrics. In the present study we used environmental and ichthyological data from 457 fish samplings distributed among 299 sampling sites within 84 different water bodies collected from 1995 to 2012 to develop: 1) new lists of expected species for six homogeneous zones identified in the Reno basin (Italy) and in the eastern regional basins of the Emilia-Romagna region; and 2) the threshold values for their species-specific abundance. Results were set as refined reference conditions (RRCs) for two of the metrics used in the application of the NISECI index in the study area (i.e. X1, relating to indigenous species and X2,b, for the abundance of expected species). The RRCs were tested by applying NISECI to 24 monitoring sites of the regional surface water monitoring network (i.e., ARPAE) and comparing the results with the application of NISECI using the GRCs. Furthermore, the analytical power of the refined NISECI was evaluated by relating the findings to three expert-based blind assessments of fish community ecological status. The results confirmed an increase in refined NISECI values and its higher consistency with expert-based assessment, supporting the validity of the presented method for RRC development and its potential for application in other regions.

Bioavailability and Ecotoxicity of Lead in Soil: Implications for Setting Ecological Soil Quality Standards.

Ecological soil quality standards for lead (Pb) that account for soil Pb bioavailability have not yet been derived. We derived such standards based on specific studies of the long‐term bioavailability and toxicity of Pb to soil organisms and a compilation of field data on the bioaccumulation of Pb in earthworms. Toxicity thresholds of Pb to plants, invertebrates, or microorganisms vary over more than 2 orders of magnitude, and the lowest values overlap with the range in natural Pb background concentrations in soil. Soils freshly spiked with Pb2+ salts exhibit higher Pb bioavailability and lower toxic thresholds than long‐term aged and leached equivalents. Comparative toxicity tests on leaching and aging effects suggest using a soil Pb threshold that is 4.0 higher, to correct thresholds of freshly spiked soils. Toxicity to plants and earthworms, and microbial N‐transformation and bioaccumulation of Pb in earthworms increase with decreasing effective cation exchange capacity (eCEC) of the soil, and models were derived to normalize data for variation of the eCEC among soils. Suggested ecological quality standards for soil expressed as total soil Pb concentration are lower for Pb toxicity to wildlife via secondary poisoning compared with direct Pb toxicity to soil organisms. Standards for both types of receptors vary by factors of approximately 4 depending on soil eCEC. The data and models we have collated can be used for setting ecological soil quality criteria for Pb in different regulatory frameworks. Environ Toxicol Chem 2021;40:1948–1961. © 2021 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Risks posed by per- and polyfluoroalkyl substances (PFAS) on the African continent, emphasizing aquatic ecosystems.

Per- and polyfluoroalkyl substances (PFAS) are organic pollutants that may have adverse effects on the ecosystem. Despite the global presence of PFAS, knowledge of PFAS on the African continent is limited because monitoring of PFAS is challenging and often not feasible owing to the lack of analytical capacity and high cost. However, it is necessary to understand the environmental risks posed by these chemicals in developing countries, because increasing urbanization will likely increase PFAS contamination in the environment. Although, as far as is known, PFAS concentrations in the African aquatic environment are generally lower than in more developed countries, exceedances of ecological quality standards (EQS) were reported in a few cases, providing evidence of potential ecological risks to these ecosystems. However, the number of ecosystems at risk will likely increase as urbanization and modernization increase in African countries. Therefore, environmental regulations should be updated and implemented to reduce further contamination of the aquatic environment with these chemicals. In addition, analytical laboratories in Africa should develop their capacity to detect PFAS and related compounds regularly and routinely. Local hot spots need to be identified, the influence of these hot spots on the PFAS burden in the environment should be investigated, and environmental regulations should be implemented for these hot spots to reduce their environmental impact. Therefore, we recommend a more routine monitoring of PFAS, including new PFAS that are currently used as perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) alternatives, which are not regulated and environmentally concerning. Integr Environ Assess Manag 2021;17:726-732. © 2021 SETAC.

Hydrodynamics Alter the Tolerance of Autotrophic Biofilm Communities Toward Herbicides.

Multiple stressors pose potential risk to aquatic ecosystems and are the main reasons for failing ecological quality standards. However, mechanisms how multiple stressors act on aquatic community structure and functioning are poorly understood. This is especially true for two important stressors types, hydrodynamic alterations and toxicants. Here we perform a mesocosm experiment in hydraulic flumes connected as a bypass to a natural stream to test the interactive effects of both factors on natural (inoculated from streams water) biofilms. Biofilms, i.e., the community of autotrophic and heterotrophic microorganisms and their extracellular polymeric substances (EPS) in association with substratum, are key players in stream functioning. We hypothesized (i) that the tolerance of biofilms toward toxicants (the herbicide Prometryn) decreases with increasing hydraulic stress. As EPS is known as an absorber of chemicals, we hypothesize (ii) that the EPS to cell ratio correlates with both hydraulic stress and herbicide tolerance. Tolerance values were derived from concentration-response assays. Both, the herbicide tolerance and the biovolume of the EPS significantly correlated with the turbulent kinetic energy (TKE), while the diversity of diatoms (the dominant group within the stream biofilms) increased with flow velocity. This indicates that the positive effect of TKE on community tolerance was mediated by turbulence-induced changes in the EPS biovolume. This conclusion was supported by a second experiment, showing decreasing effects of the herbicide to a diatom biofilm (Nitzschia palea) with increasing content of artificial EPS. We conclude that increasing hydrodynamic forces in streams result in an increasing tolerance of microbial communities toward chemical pollution by changes in EPS-mediated bioavailability of toxicants.

Long-term trends of phosphorus concentrations in an artificial lake: Socio-economic and climate drivers.

European freshwater ecosystems have undergone significant human-induced and environmentally-driven variations in nutrient export from catchments throughout the past five decades, mainly in connection with changes in land-use, agricultural practice, waste water production and treatment, and climatic conditions. We analysed the relations among concentration of total phosphorus (TP) in the Slapy Reservoir (a middle reservoir of the Vltava River Cascade, Czechia), and socio-economic and climatic factors from 1963 to 2015. The study was based on a time series analysis, using conventional statistical tools, and the identification of breaking points, using a segmented regression. Results indicated clear long-term trends and seasonal patterns of TP, with annual average TP increasing up until 1991 and decreasing from 1992 to 2015. Trends in annual, winter and spring average TP concentrations reflected a shift in development of sewerage and sanitary infrastructure, agricultural application of fertilizers, and livestock production in the early 1990s that was associated with changes from the planned to the market economy. No trends were observed for average TP in autumn. The summer average TP has fluctuated with increased amplitude since 1991 in connection with recent climate warming, changes in thermal stratification stability, increased water flow irregularities, and short-circuiting of TP-rich inflow during high flow events. The climate-change-induced processes confound the generally declining trend in lake-water TP concentration and can result in eutrophication despite decreased phosphorus loads from the catchment. Our findings indicate the need of further reduction of phosphorus sources to meet ecological quality standards of the EU Water Framework Directive because the climate change may lead to a greater susceptibility of the aquatic ecosystem to the supply of nutrients.

Fish in Tidal Freshwater Transitional Waters in Ireland: recommendations for assessment, policy and management of ecological quality under the Water Framework Directive (WFD)

As part of the national monitoring programme under the Water Framework Directive (WFD), seine, trawl and fyke net samples were taken of fish from thirteen locations in Tidal Freshwater Transitional Waters (TFTW) around Ireland. The results were highly variable, with some hauls completely empty while others returned high numbers of individuals, usually dominated by a single species. Thirty-four species were recorded, of which Pomatoschistus microps and Platichthys flesus accounted for 63% of all individuals. Seine netting was the most successful in terms of both number of species and abundance, and consequently had the highest diversity metric values. The fish communities of the Lee, the Tolka and the Slaney systems were significantly different from the others. While the Lee had markedly fewer species (S = 3) and lower abundance (N = 8) than the rest, the Tolka had relatively high S (13) and the highest total abundance (N = 4,089). In terms of ecological quality standards (EcoQS), the relative consistency of diversity metrics offers some prospect of setting meaningful quality thresholds. Multimetric indices, incorporating fish guild and functional criteria could be more reliable, but the actual thresholds may have to be linked to the individual systems.

THE CONCEPTUAL BACKGROUND FOR DEVELOPMENT AND IMPLEMENTATION OF ECOLOGICAL QUALITY STANDARDS IN AGRICULTURAL PRODUCTION

The paper covers contemporary approaches to provision of quality and safety of food products. The factors influencing the development process and compliance of ecological quality standards for the products of agriculture are substantiated. It is proved, that the interests of the state, local authorities and private sector in the process of economic use of renewable natural agricultural resources should be taken into consideration primarily at the stage of development and implementation of standards. The triad model of stateprivate partnership in the sphere of implementation of ecological quality standards for agricultural production and environment is suggested, the realization of which will promote synergetic effect in economic, ecological and social sphere through respecting the interests of participants.

Ecological Status as a Legal Construct—Determining its Legal and Ecological Meaning: Figure 1.

For a meaningful discussion of the effectiveness of ecological objectives and ecological quality standards, their terms and purposes must be examined and clarified. This study explores the terms and content of ecological quality objectives and ecological quality standards, based on the Water Framework Directive’s legal conceptualization of ‘ecological status’. This exploration is accomplished by analysing and describing the Water Framework Directive’s ‘ecological status’ aspect from a legal-ecological perspective. The analysis of ‘ecological status’ and its main constructs forms the basis for a possible alternative form of regulation, which addresses the shortcomings identified in the analysis.

Biomarkers: Are realism and control mutually exclusive in integrated pollution assessment?

The conventional view of pollution monitoring is that any choice is a trade-off between realism and precision, as the control over confounding variables decreases with the increasing degree of organization of the test system.Dublin Bay is subject to considerable anthropogenic pressures and there have been many attempts to quantify the status of the system at organizational levels from DNA strand breaks (Comet) to the system itself (Ecological Network analysis, ENA).Using Dublin Bay as an example, the data show there was considerable variability at all levels of organization. At intracellular level, Lysosome Membrane Stability (LMS, assessed by Neutral Red Retention, NRR) varied almost 4-fold with season and individual condition, while the community level AZTI Marine biotic Index (AMBI) had a similar range within a single, supposedly homogeneous, site. Overall, there was no evidence that biomarkers of the lower levels of organisation reduced the variability of the measure, despite the extra control over influencing variables, nor was there any evidence that variability was additive at higher levels of organisation.This poses problems for management, especially given the fixed limits of Ecological Quality Standards (EQSs). Clearly while the integrated approach to pollution monitoring does offer the potential to link effects across the organizational range, it should also be possible to improve their capability by widening the database for reference values, particularly at the higher level of organization, and by process models, including the confounding variables found in the field, for those at lower level.

The Water Framework Directive--A Directive for the Twenty-First Century?

For a meaningful discussion of the effectiveness of ecological objectives and ecological quality standards, their terms and purposes must be examined and clarified. This study explores the terms and content of ecological quality objectives and ecological quality standards, based on the Water Framework Directive’s legal conceptualization of ‘ecological status’. This exploration is accomplished by analysing and describing the Water Framework Directive’s ‘ecological status’ aspect from a legal-ecological perspective. The analysis of ‘ecological status’ and its main constructs forms the basis for a possible alternative form of regulation, which addresses the shortcomings identified in the analysis.

The impact of an additional ecotoxicity test on ecological quality standards

The present study aims to support decisions on whether or not to perform an extra toxicity test in order to improve environmental quality standards (EQSs). The impact of an additional ecotoxicity test was analyzed by predicting new ecotoxicity values with three different estimation methods and adding them to existing species sensitivity distributions (SSDs) on which the EQSs are based. The results show that EQSs are likely to increase due to increasing sample size, but the change also depends on the number of toxicity values available, the estimation method used and the representativeness of the species tested. The management consequences are illustrated in a case study on contaminated freshwater sediment in the Netherlands. It is shown that a slight increase of the EQS can result in a large reduction of sediment remediation costs without impairing regulatory protection levels. The paper identifies indicators that can be used to evaluate the potential impact of an extra ecotoxicity test.

Calibration of Littoral Diatoms to Water Chemistry in Standing Fresh Waters (Flanders, Lower Belgium): Inference Models for Historical Sediment Assemblages

Relationships between littoral surface-sediment diatom assemblages and ambient limnological conditions were examined in 186 lentic fresh waters throughout lower Belgium (Flanders). Most of these waters were small, unstratified, alkaline and rich in nutrients. Using weighted-averaging techniques, robust and accurate transfer functions were developed for median pH-values ranging from 3.4 to 9.3 and dissolved inorganic carbon concentrations from <1.6 to 63 mg l−1 (jackknifed r 2≈ 0.87, RMSEP <10% of the observed range), while a less precise model was obtained for sodium (2–571 mg l−1; jackknifed r 2 0.69, RMSEP 9.9% of the range). Restricting the data set to circumneutral and alkaline sites (pH≥6.5) revealed the importance of additional variables, including calcium, silica, chemical oxygen demand and potential gross oxygen production (a proxy for metabolic activity and phytoplankton abundance). Calibration models for these variables were strong enough to be useful (jackknifed r 2 0.57–0.59, RMSEP 13.1–16.4% of the observed range), although estimations should not always be considered entirely independent. Except for the predominant pH gradient, removal of all taxa with a distribution unrelated to the variable of interest improved model performance. In general, such taxa were proportionally represented among taxa classified according to their principal habitat. Application of the present models to diatom assemblages of shallow-water sediments obtained from historical samples and, most importantly, herbarium-macrophyte specimens, will improve hindsight into regional freshwater conditions and add to base-line setting of ecological quality standards in a highly impacted region.

The Progression Towards Ecological Quality Standards

Environmental law still lacks coherence in many respects. Two key areas of UK and EC law—water pollution control and biodiversity protection—are examined to see whether it is possible to adopt more common approaches. A key development in pollution control law was its redirection in the last twenty years from a largely reactive instrument towards one embedded in the realisation of environmental quality objectives through precisely stated quality standards. On closer inspection, many of these standards, though, are anthropocentric in origin. The approach of using the law purposively to achieve defined objectives is much better developed in pollution legislation as compared to the law on biodiversity protection. The latter area now needs to see a similar development in ecological quality standards, while recognising that their formulation is a significantly different exercise from that of establishing environmental quality standards. The use of ecological quality standards in the Water Framework Directive is commendable, but there remain substantial reservations about the criteria adopted and the underlying basis for ecological valuation.

Editor's Foreword

Laws dealing with different aspects of the environment have often developed at different times and with distinct philosophical approaches—so much so that it is sometimes questionable whether environmental law can be said to be a truly coherent discipline. In The Progression Towards Ecological Quality Standards , William Howarth of the University of Kent attempts to seek greater synthesis in two key areas of contemporary environmental law—pollution control and nature protection. Using water as his common medium, he shows how UK pollution law, heavily influenced by European Community law, is currently driven by the need to attain environmental quality objectives based on precisely formulated environmental standards. He argues that nature protection law dealing with the water environment now needs to see a similar development in the use of ecological quality standards as a core legal mechanism. The Water Framework Directive has indeed made use of such standards, but Professor Howarth, though...

Fishes as indicators of environmental and ecological changes within estuaries: a review of progress and some suggestions for the future

Estuarine habitats, and the fish assemblages associated with them, are potentially impacted upon by many anthropogenic influences which can have a direct influence on the food resources, distribution, diversity, breeding, abundance, growth, survival and behaviour of both resident and migrant fish species. The direct and indirect coupling between ichthyofaunal communities and human impacts on estuaries reinforces the choice of this taxonomic group as a biological indicator that can assist in the formulation of environmental and ecological quality objectives, and in the setting of environmental and ecological quality standards for these systems. This review examines the rationale and value of selecting fishes as bio‐indicators of human induced changes within estuaries, using examples from both the northern and southern hemispheres. The monitoring of estuarine ‘health’ using fish studies at the individual and community level is discussed, with an emphasis on the potential use of estuarine fishes and their monitoring and surveillance in national and international management programmes. In illustrating the above concept, examples are presented of the way in which fishes are threatened by anthropogenic impacts and of the way in which teleosts can contribute to a monitoring of estuarine ecosystem health.