In both Sweden and Finland, water law has traditionally provided strong protection for hydropower operations by issuing permanent environmental licences. This national protection has started to erode as a result of the requirement of the European Union (EU) Water Framework Directive (WFD) for permit reviews to improve the ecological status of rivers. In the light of this dynamic between European and national frameworks, this article compares the Swedish and Finnish implementation of the WFD regarding existing hydropower operations. Whereas Sweden has adopted comprehensive legislative and policy reforms that embrace a systemic perspective on reconciling hydropower with the current societal and ecological circumstances, Finland has relied on bottom-up collaborative processes at the grassroots level. The article shows that both approaches are problematic in so far as they push the boundaries of proper implementation of the WFD and, by extension, the achievement of the ecological objectives of the WFD in waters affected by hydropower. Our comparison highlights tensions between EU law requirements for formal legal effectiveness in national implementation, and the WFD's aspirations for adaptive river basin-based governance.

In late 2000, the European Union adopted the Water Framework Directive (WFD) and funded a series of research and innovation projects to support its implementation. One of these was the MULINO project (MULti-sectoral, INtegrated and Operational Decision Support System for Sustainable Use of Water Resources at the Catchment Scale). Its main product was a decision support system (mDSS) tool designed to help water managers make choices related to WFD implementation in a participatory manner. After the end of MULINO, a long sequence of research projects allowed for the maintenance and continuous development of its tool, which has been applied for more than 20 years in various contexts related to environmental and integrated management. This experience and an analysis of the literature allow us to draw some general conclusions regarding DSS tools for water management and their role in our societies. Lessons learned are proposed, from the need to frame tools within sound methodological frameworks for the management of decision processes, supporting instead of substituting decision-makers in their roles, to the trade-offs that appear between ease of use and specificity on one side and flexibility and reusability on the other. The specific strengths attributed to mDSS include the provision of an interface based on a simplified and understandable conceptual framework that facilitates communication with interested parties, the flexibility and ability to approach a wide variety of decisional issues, the relatively simple and understandable decision rules provided by the tool, and the simplified connections with other software environments. This paper presents the current version of the software and reports on the experience of its development and use over more than two decades; it also identifies the way forward.

This paper seeks to relate strategic themes in water resources management to the practicalities of imposing particular regulatory measures on water uses and to protect aquatic ecosystems. Specifically, a contrast is drawn between the global imperative of Integrated Water Resources Management (IWRM) and the sectoral (issue-by-issue) approach to water regulation that has traditionally prevailed in both regional (EU) and national legislation. The intuitive attractions of ‘integration’ are contrasted with the challenges of interrelating this to the diverse purposes for which water legislation is adopted, both for human needs and for ecological purposes. These challenges are well illustrated in the EU Water Framework Directive (WFD) which purports to adopt an ‘integrated’ approach, but is actually concerned with water quality, largely to the exclusion of other water-related concerns. Insofar as the Directive does seek to secure integration between water quality and water quantity concerns in surface water, this is only done in a secondary or incidental way. Water flow becomes relevant only where specified environmental objectives under the Directive are not being met. However, the legally contingent status of flow has been bolstered markedly by recent guidance on ecological flows under the WFD Common Implementation Strategy. The significance of this guidance is discussed and related to the implementation challenges that it raises. In relation to the UK, and particularly England, it is argued that the response to addressing water flow issues arising under the WFD had been dilatory and inadequate. Concluding observations reflect on the global, regional and national challenges to integration of water legislation as they have been illustrated by the discussion of regulating for ecological water flows.

The within-site patchy distribution of organisms represents a natural source of variability that can bias the precision of biotic indices. This study aims to evaluate the spatial distribution of benthic macroinvertebrates and its effects on the biotic index used in Italy for assessing the ecological status of rivers. Two main issues were considered: the sampling design and the minimum number of replicates which are necessary to achieve a given precision level. To this purpose, 30 surber replicates were taken, instead of the ten required for the application of the index, in a homogeneous reach of a mid-sized perennial river (Trebbia River, Northern Italy). The percentile confidence interval (p.c.i.) of the index was calculated from 1000 possible communities with the resampling method and the bootstrap procedure. The 95% p.c.i. varied from 0.195 to 0.227, which is great considering that the index ranges from 0 to 1. The metrics based on abundance data were especially affected by the heterogeneous distribution of organisms. The resulting precision of the index increased only partially when doubling the sampling effort.

Banks of navigable canals are often stabilized with “hard” materials resulting in unsuitable conditions for marginal riparian vegetation. A constructed marginal shallow and sheltered water zone can favour riparian vegetation. In 1998, a new canal branch with shallow water zones was constructed along the canal Ghent-Bruges (Belgium). This study analysed plant vegetation development of these shallow zones, its spatial variation and its mid-way succession. For this purpose, riparian vegetation was investigated by plots in the middle of the shallow water zones, on the canal bank side and on the defence dam side in 2006 and 2009. The studied shallow water zones permitted the development of helophyte vegetation on the sides but hardly in the middle. Differences in number of taxa, diversity-index and Grime's competitiveness and ruderality were observed on the sides. The application of different construction materials is discussed as a possible cause. An increase of competitiveness and a decrease of ruderality indicated vegetation succession during the period 2006–2009. Rooted aquatic plant vegetation was poorly developed in the studied shallow water zones probably due to the deposition and accumulation of fine sediments. The results were interpreted in relation to possible design principles of shallow water zones and might be useful for waterway managers, policy-makers and technicians in future bank engineering projects along navigable canals. Moreover, the study contributes to the knowledge of mitigating negative ecological effects associated with navigation. Such bank rehabilitation measures may be necessary to achieve the ecological goals of the European Water Framework Directive.

Typology schemes are useful in partitioning natural spatial variability and thus helping implementing bioassessment methods. They have become widely accepted in Europe after the publication of the Water Framework Directive (WFD). The major objective of this study was to test if six Portuguese pre-defined physical stream-types (using System-B of the WFD) are concordant with macroinvertebrate assemblages collected in 31 undisturbed sites in a Portuguese river basin. A top-down (stream types defined by physical attributes) and a bottom-up approach (river classes defined by biological communities) were used. No significant differences were found in the mean number of taxa and abundance of different physical stream types and few taxa are characteristic of specific stream types. Discriminant analysis (DA) considering family-level composition revealed that all stream-types were significantly different and the cross-validation process showed that all stream-types had more than 50% of their samples correctly assigned. On the other hand, the bottom-up approach based on a correspondence analysis (CA) showed some overlap of the  macroinvertebrate communities of pre-defined stream types, indicating that variations in the macroinvertebrate community structure was primarily related to altitude, mineralisation and a temporal gradient. DA cross-validation and CA results suggest that tested stream types do not account for natural temporal changes known to affect macroinvertebrate communities in this Mediterranean basin and that the WFD typology should account for these natural variations. The exclusion of natural variability could indicate impairment when it does not exist or no impairment when it does exist (type I and II statistical errors).

The habitats of 356 phytocoenoses dominated by 15 species of aquatic plants were investigated. Among the properties of water, Na+, pH, total Fe, Ca2+, NO3−, SO42−, hardness and COD-KMnO4 were the most important in differentiating the habitats of the phytocoenoses studied. Considerable physicochemical differences were found between the waters of the phytocoenoses of Ranunculus circinatus (hard waters rich in Na+), Nuphar pumila (soft waters with high levels of total Fe), Elodea canadensis, Ceratophyllum demersum (alkaline waters) and Stratiotes aloides (waters containing high concentrations of Ca2+ and SO42−). The substrate properties that best differentiated the habitats compared were PO43−, hydration, organic matter content, total N, dissolved SiO2, Ca2+, Na+ and pH. Patches of R. circinatus inhabited substrates containing the highest levels of PO43−. Those of S. aloides were associated with substrates poor in PO43−. Patches of C. demersum were confined to substrates rich in total N. Phytocoenoses of R. circinatus were associated with large lakes, whereas those of N. pumila were restricted mostly to smaller lakes. The deepest parts of lakes were inhabited by Potamogeton lucens. Phytocoenoses of S. aloides occurred mostly in shallow waters, on thick sediments. The investigated phytocoenoses also represent different stages of succession. The phytocoenoses of Potamogeton perfoliatus, R. circinatus, Myriophyllum spicatum and Polygonum amphibium, which develop on mineral substrates, initiate the process of succession, whereas those of Myriophyllum verticillatum, Nymphaea candida, Nymphaea alba, N. pumila and S. aloides, which inhabit highly hydrated organic substrates, are characteristic of the late stages of succession.

The aquatic larvae of the Diptera are often the most abundant and most diverse group of the benthic macroinvertebrate fauna.They are able to survive in and colonise practically all freshwater habitats, and some species can tolerate harsh environmentalconditions. They are therefore both a qualitatively and quantitatively important group of biological indicators for assessing freshwatersystems. On the other hand their determination at the species level is very difficult. This is in part due to a lack of taxonomicwork in the group, but also the absence of comprehensive determination keys, that meet the needs of water managers. Asa result, the aquatic larvae of the Diptera often play a subordinate role in water management. In light of the EU Water FrameworkDirective the present work is a first step in improving the integration of the important group of the Diptera in water managementpractice: a comprehensive determination key, which is geared at water managers. The key includes 60 taxa, largely at the familyand genus level. In contrast to already existing keys the present work tries to differentiate the taxa on the basis of simple anduser-friendly characters. Numerous figures allow for easy checking of determination results. The key is applicable in Germany,Scandinavia, Great Britain and the Benelux states. Mainly taxa from running water systems are considered, but the key can alsobe used at the family level to determine taxa from standing water bodies.

Diatoms are good environmental indicators and are often the main component of phytobenthos, one of the key groups of organismsrecommended by the Water Framework Directive (W.F.D.) for the assessment of ecological status of surface waters.Although diatoms are regularly used as indicators in rivers and in lakes, less is known about the benthic diatom communities inwetland systems, especially in Italy. The main aim of the project was to provide a contribution to the knowledge on distribution,composition and structure of benthic diatom communities in wetland systems in Italy. In 2005, we investigated the benthic diatomcommunities and their relationships to water variables of nine ponds and wetlands along the Tyrrhenian coast near Rome.Furthermore, a first application of seven European diatom-based indices on this type of water body was undertaken. A total of225 species and varieties belonging to 54 genera were identified. The Canonical Correspondence Analysis indicated that certainspecies were closely associated with each wetland type and their distribution mainly depended on nutrient and chloride contents:pollution tolerant species (i. e. Luticola goeppertiana, Mayamaea atomus, Navicula subminuscula) in the wetlands connected toriver mouths, halophilous species and also marine littoral species (i. e. Nitzschia elegantula, Amphora coffeaeformis, Achnanthesbrevipes var. intermedia, Epithemia adnata var. porcellus) in the coastal brackish ponds and wetlands, and less eutrophic species(i. e. Achnanthidium minutissimum, A. biasolettianum) in the lowland freshwater wetland. In general, the indices classifiedmost of the studied water bodies as bad, poor and moderate status; few sites were classified into a good class, even for at leastin one sampling occasion. Eutrophication and Pollution Index (EPI-D), Trophic Diatom Index (TDI), Taxa Pollution Tolerant(%PT), Pollution Sensitivity Index (IPS) and Generic Diatom Index (IDG) were significantly correlated to nutrient contents inthe studied wetlands. Our preliminary data set illustrated the potential of the use of these benthic algae as bioindicators in wetlands.

The paper proposes a new biological method for assessing the quality of lakes. It is based on the comparison of littoral and profundal macroinvertebrate communities sampled in soft sediments. Two depths were sampled: one at the littoral zone (Zl = 2m) to define a littoral index (Bl ) related to the biogenic potential of the lake (quantitative data), the other at the deep zone (Zf = 0.66 Zmax) to define a taxonomic deficit index (Df ) connected with the quality of the water-sediment interface in deep zone (qualitative data). These two indexes were combined in a Lake Biotic Index (LBI), with a range from 0 to 20, which gives an evaluation of the biogenic capacity of a lake to the development of macroconsumer communities. Using the Bl and Df values any lake can be plotted on a typological graph which is helpfull to characterize lakes both quantitatively (oligo- to polybiotic) and qualitatively (eu- to dysbiotic). Lake Châlain (French Jura) is presented as an example of the method application with its macrofauna and the index calculation. Then, this lake was included in the typological graph with nine other French lakes studied using the same method. Each lake, characterized by its Bl, Df and LBI values, can be compared to the others in a typological scheme. The proposed indexes are discussed and bases for interpretation of the results are presented. The proposed classification of lakes gives an evaluation of their biogenic capacity concerning macroconsumers and can be usefully compared with other classifications, especially with trophic and sediment types, in functional studies as well as in lake diagnosis, in the context of the Water Framework Directive (Directive 2000/60/CE).