Search Results (5)

Water Framework Directive (WFD) guidance documents from 2019 provide a comprehensive review of methods and guidelines to improve the comparability of heavily modified water bodies (HMWBs) in the European Union. However, there is currently no common, single methodology for monitoring HMWBs and artificial water bodies (AWBs) or for determining maximum (MEP) and good ecological potential (GEP). This study presents the first assessment of hydromorphological conditions of HMWBs and AWBs in Croatia based on type-specific indicators. The typology of HMWBs and AWBs was based on distinct hydromorphological characteristics and modifications in order to be easily related to the uses of the water bodies. The classes of hydromorphological potential were graded from the theoretical MEP, which was determined by the score scale as the tolerated deviation from natural reference conditions, considering potential mitigation measures. The use of the water body and/or the effects on the wider environment were considered while determining MEP and choosing indicators included in monitoring and assessment. In the case of AWBs, the parameters dependent on natural reference conditions, which are non-existent, were omitted from the assessment. Only 27% of HMWBs and 2 out of 51 AWBs achieved good potential for all three hydromorphological elements. The most significant hydromorphological modifications include channelization, straightening, deepening and removal of riparian vegetation due to flood-protection management practices. In order to achieve the environmental objectives set out by the WFD, the Croatian water management system has to start implementing mitigation measures, especially related to natural flood management. Full article

The Water Framework Directive (WFD) is the European legislation on water policy that assesses water quality according to time-consuming metrics and specific taxonomic needs. In this sense, the objective of this study was to evaluate the sensitivity of Daphnia magna feeding rate assays to assess/discriminate the water quality of heavily modified and artificial water bodies. Monthly, for one year, the quality of the Crestuma-Lever reservoir (in two sampling sites: Crestuma and Marina) was assessed using physical, chemical, and biological (concentration of chlorophyll-a) elements proposed by the WFD. Additionally, D. magna was exposed to the collected water samples and the feeding rates were evaluated to include an ecosystem function evaluation in water quality assessment. The WFD metrics showed that, overall, the Crestuma-Lever reservoir has a rating of Good to Moderate Ecological Potential, regardless of site. Feeding rates varied with the sampling site and months, demonstrating that feeding behavior evaluation is a sensitive tool that allows discriminate potential effects indicative of a lower water quality. This finding was recorded by the decrease in the feeding rate (Crestuma: May, Sept; Marina: Nov, Jan, May), despite the WFD classification, and once the organisms are affected by the components present in the water samples. Full article

Stickleback (Gasterosteus aculeatus) is an endangered species in Catalonia. It has disappeared from most of its historical range, including at least five whole basins, and the remaining populations continue to decline. Our monitoring, carried out on most Catalan populations in the north-east of the country, indicates that over the last 15 years there has been a reduction of between 50% and 75% everywhere. Even worse, many of the remaining populations are in heavily modified Mediterranean river stretches, subjected to multiple anthropogenic pressures or highly vulnerable to increasingly drastic droughts due to climate change. In this context, in 2018 we started a project that aims to implement a long-term, low-cost strategy for the conservation of this species in Catalonia. We have opted for a combination of broad-spectrum alternative measures: (1) Strategic restoration of small stretches of river of high interest to the species, mainly intended to ensure the maintenance of flooded pools during extreme droughts. (2) Reintroduction in river stretches with historical presence, firstly in watersheeds with extant populations. (3) Gradually, application of assisted migration to water bodies without historical presence, but with good ecological conditions for a probable successful establishment. (4) Creation of new ex-situ populations in small artificial water bodies, from urban ornamental ponds to small irrigating reservoirs, reaching agreements with the owners, and often carrying out essential previous actions, such as the exotic fish removal. (5) Continuation and extension of regular sampling, in order to implement a permanent monitoring of its trends, and expand the specific knowledge on some key aspects of its ecology. (6) Implementation of a specific environmental awareness and education campaign, as well as environmental volunteering, for the involvement of society in the conservation of this small fish and its habitats. The known genetic differentiation of the remaining populations is being taken into account in the planning of these actions. We will present the results achieved so far, and the plans for the coming years. Full article

This work intended to assess the adaptability of bioassay with Raphidocelis subcapitata to be used as a complement to the water quality assessment parameters of reservoirs imposed by the European Water Framework Directive (WFD). Thus, water samples of Portuguese reservoirs (Miranda, Pocinho, Aguieira, and Alqueva) were analyzed in three sampling periods (spring and autumn 2019, and spring 2020). A physical and chemical report of waters was also performed. R. subcapitata assay proved to be sensitive, indicating the presence of a potential perturbation that was not always associated with chemical analysis performed. In general, in the spring samplings, the water samples showed more disturbances to R. subcapitata, which in some situations may be associated with the higher content of nutrients and metals. Microalgae assay can be an effective complementary tool to indicate the ecotoxicological potential since they responded quickly to all sample components of water samples, in a wide-ranging variety of water conditions (different sites in several reservoirs). High similarities between the final ecotoxicological and the ecological potentials, according to the WFD parameters, were detected. The ecotoxicological approach based on our results allowed to confirm that bioassays with R. subcapitata are suitable and sensible to detect perturbations. Full article

Reservoirs are formed through the artificial damming of a river valley. Reservoirs, among others, capture polluted load transported by the tributaries in the form of suspended and dissolved sediments and substances. Therefore, reservoirs are treated in the European Union (EU) as “artificial” or “heavily modified” surface water bodies. The reservoirs’ pollutant load depends to a large extent on the degree of anthropogenic impact in the respective river catchment area. The purpose of this paper is to assess the mutual relation between the catchment area and the reservoirs. In particular, we focus on the effects of certain land use/land cover on reservoirs’ water quality. For this study, we selected twenty Polish reservoirs for an in-depth analysis using 2018 CORINE Land Cover data. This analysis allowed the identification of the main triggering factors in terms of water quality of the respective reservoirs. Moreover, our assessment clearly shows that water quality of the analysed dam reservoirs is directly affected by the composition of land use/land cover, both of the entire total reservoir catchment areas and the directly into the reservoir draining sub-catchment areas. Full article