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A pathways risk assessment is a part of an integrated assessment for the horizon scanning of non-indigenous species introductions. We examined past pathways, and their vectors, of aquatic NIS already present in Belarus in order to predict those species likely to spread to Belarus and arrive to Western Europe along the Central European invasion corridor. Twenty-four aquatic non-indigenous macroinvertebrates are known within Belarusian rivers, lakes and reservoirs, six of these have already spread westwards through Belarus. The modes of spread for these NIS were vessel transport, navigation corridors, and natural spread following an initial introduction.

Combined effects of cumulative nutrient inputs and biogeochemical processes that occur in freshwater under anthropogenic eutrophication could lead to myriad shifts in nitrogen (N):phosphorus (P) stoichiometry in global freshwater ecosystems, but this is not yet well-assessed. Here we evaluated the characteristics of N and P stoichiometries in bodies of freshwater and their herbaceous macrophytes across human-impact levels, regions and periods. Freshwater and its macrophytes had higher N and P concentrations and lower N : P ratios in heavily than lightly human-impacted environments, further evidenced by spatiotemporal comparisons across eutrophication gradients. N and P concentrations in freshwater ecosystems were positively correlated and N : P was negatively correlated with population density in China. These results indicate a faster accumulation of P than N in human-impacted freshwater ecosystems, which could have large effects on the trophic webs and biogeochemical cycles of estuaries and coastal areas by freshwater loadings, and reinforce the importance of rehabilitating these ecosystems.

Changes in land use and land cover (LULC) are the leading contributors to the decline and loss of ecosystem services in the world. The present study covered the Central Rift Valley lakes basin in Ethiopia, focusing on the valley floor and the East and West escarpments, to analyze changes in LULC and to estimate associated losses in ecosystem service values (ESVs). Covering both upstream and downstream areas in the basin, the study addressed major gaps in existing studies by connecting the sources and sinks of material (e.g., sediment and water) in source-to-lake systems. Additionally, the study facilitated the identification of critical areas for conserving natural resources and reversing the decline of associated ESVs in the Central Rift Valley. A post-classification comparison approach was used to detect LULC changes between 1973 and 2020 using four Landsat images from 1973, 1990, 2005 and 2020. The value transfer valuation method was used to estimate the changes in ESVs due to LULC changes. Among the seven major identified LULC classes, farmlands, settlements, and bare lands showed positive changes, while forestlands, grasslands, shrublands and waterbodies showed negative changes over the last 47 years. The expansion of farmlands, for example, has occurred at the expense of grasslands, forestlands and shrublands. The changes in LULC over a period of 47 years resulted in a total loss of US $62,110.4 × 106 in ESVs. The contributors to the overall loss of ESVs in decreasing order are provisioning services (US $33,795.1 × 106), cultural services (US $28,981.5 × 106) and regulating services (US $652.9 × 106). The results imply that addressing the degradation of land and water resources is crucial to reversing the loss of ecosystem services and achieving the national Sustainable Development Goals (SDGs) related to food and water security (SDGs 2 and 6) and life on land (SDG 15).

Apple snails are renowned for their strong impacts on aquatic vegetation and ecosystem function in invaded regions but the existing knowledge on their role in aquatic ecosystems and communities in their native range is scarce. The variation in palatability of five submersed macrophytes, the preference of Pomacea canaliculata for them and the potential effects of its differential grazing on macrophyte assemblages in Southern Pampas were investigated. In no-choice trials, macrophytes showed differences in palatability that were correlated to physical defences and not to nutritional values. In free-choice trials, preference was consistent with the palatability ranking. In a mesocosms experiment, Chara contraria and Zannichellia palustris were totally eradicated by apple snails, the coverage of Stuckenia striata increased only when they were absent and Ludwigia peploides and Myriophyllum quitense were not affected. The live biomass of Z. palustris, S. striata and M. quitense was reduced by apple snails. Total live and dead biomasses were lower, and chlorophyll-a concentrations higher, in the mesocosms with apple snails. Our results indicate that P. canaliculata has a keystone role in its native range and that its differential grazing could shape the structure and composition of submersed vegetation and promote shifts to turbid-water states or maintain them. Fil: Manara, Enzo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; Argentina Fil: Maldonado, Mara Anahí. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; Argentina Fil: Martín, Pablo Rafael. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Ecología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; Argentina

Although man-made reservoirs represent an important water supply source in countries where water scarcity has become a problem, little work has been done on the evaluation of their ecological status. Taking this in account, the general aim of this study was to assess the usefulness of ecotoxicological endpoints in the potential ecological status characterization of water reservoirs, with the purpose of their possible integration in evaluation programs developed under the Water Framework Directive (WFD). To achieve this purpose, a group of bioassays were selected to evaluate both water and sediment compartments at the Alqueva reservoir (the biggest from the Iberian Peninsula), with representative species from different taxonomic and functional groups: Vibrio fischeri, Thamnocephalus platyurus, Daphnia magna and Heterocypris incongruens. The ecotoxicological assessment showed that sublethal endpoints (e.g., luminescence, growth or reproduction), would be more useful and sensitive to identify toxicity patterns in this type of water body. In general, the results from this ecotoxicological tool-box agreed with the potential ecological status established according to the WFD, which indicates that the bioassays complement the ecological assessment. Furthermore, the use of an ecotoxicological approach can be extremely useful, especially in cases where the biotic indices are difficult to establish, such as in man-made reservoirs. However, when pollutant concentrations are very low, and/or when nutrients and organic matter concentrations are high, the two approaches do not fit, requiring further research to determine which organisms are more sensitive and the best biotic indices to use under those conditions. (C) 2015 Elsevier B.V. All rights reserved.

A 1-year cycle of physico-chemical measurements was conducted in the Marano and Grado Lagoon (Adriatic Sea, Italy) with the aim to assess its trophic state. Some selected variables (nutrients, chlorophyll a , dissolved oxygen, temperature and salinity) were used to describe the system within the application of the Water Framework Directive (WFD) and to compare it with other Mediterranean environments. From an ecological point of view the Marano and Grado Lagoon is one of the best conserved wetlands in the whole Mediterranean area and is protected by several European environmental pieces of legislation. However, the neighbouring mainland hosts several socio-economic activities which can affect its water quality. The results obtained in this work highlighted considerable spatial and temporal variability of physico-chemical parameters. Specifically, a large amount of anthropogenic nutrients, mainly in form of nitrogen (N), was carried from inland through river discharges in the Marano basin (western sector). However, these inputs were offset by the water exchange with the adjacent open sea, which exerted a dynamic dilution effect, and induced low water residence time thus limiting nutrients enrichment and their accumulation for long time periods. The Molar Redfield ratio (DIN/SRP) was always higher than the optimum value of 16 (in some cases it was up to 2000), thus suggesting that the system is phosphorus (P) limited, as confirmed by low chlorophyll a content, rare algal blooms and good water oxygenation. Trophic state indices and threshold values (EEA method, Carlson Trophic Index, TRIX and ASSETS) were applied. A broad range of classes was found (from oligotrophic to hypertrophic depending on water bodies, method applied and period of the year), thus suggesting that an over simplification of this complex ecosystem should be avoided. Further studies will be conducted in order to define the Lagoon’s ecological status sensu WFD and the adequate management implications.

SUMMARYThe effects of plerocercoids of the cestodeTriaenophorus nodulosusinfecting the livers of native Eurasian perchPerca fluviatilisand non-native pumpkinseedLepomis gibbosuswas investigated in 17 sites along the Moselle watershed. With a single exception, infected individuals were not observed in the main channel whether or not northern pikeEsox lucius, a final host, was present. In ponds where the pike was present, the prevalence ofT. nodulosusaveraged 86% in Eurasian perch and 15% in pumpkinseed. The parasite was not present at all in ponds when pike were absent. Parasite load, hepatosomatic index (HSI), gonadosomatic index (GSI) and body condition index (CI) were compared between hosts in one site where parasite prevalence and fish abundance was highest. HSI in infected perch was significantly higher than in uninfected perch, whereas no differences in HSI were detected between infected and uninfected pumpkinseed. While perch were more frequently infected and had a greater average parasite load than pumpkinseed, there were no significant differences in either indicator between the two species. Furthermore, no significant differences in GSI or CI were observed between infected and uninfected fish in either species, by either gender or maturity stage. We hypothesize that pumpkinseed is more resistant to the parasite or less likely to feed upon infected copepods than perch.