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A lectotype (male) and paralectotypes (male, female) of Pneumia vittata (Tonnoir, 1919) comb. nov. (= Pericoma crispi Freeman, 1953 syn. nov.) from Belgium are designated. The species is redescribed and illustrated, and a differential diagnosis is given. The former designation of a holotype, paratypes and paratypoids by Jung is invalid because it was not published. In addition, a problem with Tonnoiriella obtusa (Tonnoir, 1919) comb. nov. (= Tonnoiriella anchoriformis Salamanna, 1975 syn. nov.) from Belgium is resolved. A female specimen is designated as a lectotype, but only the dissected wings from this specimen are in condition suitable for redescription. There is additional non-type material collected later by Tonnoir; this material, including 3 females and 1 male, was the basis for redescription, illustrations and differential diagnosis. The unpublished male lectotype designated by Jung is invalid. Two species are added to the last checklist of Psychodidae from Belgium, raising the total number to 94.

The Rwenzori Mountains and Albertine Rift region of southwestern Uganda are part of a globally recognized biodiversity hotspot, but are currently facing pressures from intensified agriculture, mineral exploitation and hydroelectric power generation. This study was undertaken to assess the ecological water quality of Rwenzori rivers using biomonitoring metrics to determine the major factors shaping macroinvertebrate community structure in disturbed and undisturbed sites. We sampled macroinvertebrates at 66 sites along headwater tributaries and downstream areas of the Nyamwamba, Mubuku and Nyamugasani rivers, supplemented by five sites along the Kazinga channel and Lake George wetland, and identified a total of 32,579 macroinvertebrates to family level. Insecta was the most diverse taxon (45 families). Based on Average Score Per Taxon (ASPT) scores, sites were classified into four ecological water quality groups as excellent (40 sites), good (16), fair (7) and poor (8). Upstream sites had the highest abundance of pollution-sensitive families such as Caenidae and Hydropsychidae, while downstream sites had high numbers of Chironomidae. Lorenz curves revealed a low degree of evenness with Gini coefficient values ranging from 0.75 to 0.94. Ordination analysis revealed that total phosphorus, specific conductivity, chloride and chemical oxygen demand were key environmental variables contributing to variation among the sites. The majority of sites did show little to no anthropogenic influence with the exception of downstream sites. The results of this study provide useful baseline reference data, to assess and better manage the impacts of anthropogenic activities on the ecological integrity of the region’s aquatic systems. Furthermore, these datasets will advance the development of a regional family-level biotic index.

Adequate environmental management in tropical aquatic ecosystems is imperative. Given the lack of knowledge about functional diversity and bioassessment programs, management is missing the needed evidence on pollution and its effect on biodiversity and functional ecology. Therefore, we investigated the composition and distribution of the macroinvertebrate community along two rivers. Specifically, 15 locations were sampled in the Coca and Aguarico Rivers (Ecuadorian Amazon) and the macroinvertebrates were used to indicate water quality (WQ), expressed as the Biological Monitoring Working Party Colombia (BMWP-Col) classes. Results indicate that elevation, pH, temperature, width, and water depth played an important role in the taxa and functional feeding groups (FFG) composition. The results show that diversity of taxa and FFG were generally scarce but were more abundant in good quality sites. Collector-gathers (CG) were, in general, dominant and were particularly abundant at low WQ and downstream sites. Scrapers (SC) were the second most abundant group, dominating mostly at good WQ and upstream sites. Predators (PR) were homogeneously distributed among the sites, without clear dominance, and their abundance was slightly higher in sites with medium-low WQ and downstream sites. Lastly, both shredders (SH) and collector-filterers (CF) were almost absent and were more abundant in good quality sites. The findings of this research can be used as baseline information in the studied region since a dam was constructed two years after the sampling campaign, which has been operating since. Furthermore, the results can be used to fill the knowledge gaps related to the bioassessments of other similar systems, particularly for a tropical rainforest.

Batrachochytrium dendrobatidis is responsible for amphibian declines worldwide. Decreasing the aquatic density of this chytrid through consumption of its infectious zoospores by Cladocera (water fleas) may mitigate the impact of chytridiomycosis. Understanding this predator-prey relationship requires insights in the zoospore ingestion rate of an average water flea, but such data are almost non-existent. We investigated the functional response of Simocephalus vetulus and Chydorus sphaericus feeding on B. dendrobatidis zoospores. These Cladocera commonly occur in farmland ponds, which may represent a major habitat for disease control. Both water fleas actively ingested zoospores and their per capita ingestion rate was best modelled in function of zoospore-to-Cladocera ratio, implying mutual interference among water fleas during zoospore feeding. The larger S. vetulus substantially consumed more zoospores, characterised by a maximum ingestion rate of 2.5 × 105 zoospores.Cladocera−1.h−1.mL−1, which is about 12 times higher than for C. sphaericus. These findings are useful to support model-based management of chytridiomycosis.

The Rwenzori region in Uganda, a global biodiversity hotspot, is currently undergoing exponential economic and population growth, which puts continuous stress on its freshwater ecosystems. In Sub-Saharan Africa, biomonitoring campaigns using region-specific biotic indices is limited, particularly in Uganda. In this research, we present the Rwenzori Score (RS), a new macroinvertebrate-based biotic index developed to specifically assess the aquatic health of Rwenzori streams and rivers. We collected and measured both biological and physicochemical variables and identified 34,202 macroinvertebrates, belonging to 64 different taxa. The RS was developed in two steps. First, using canonical ordination, we identified chemical variables that correlated significantly with gradients in macroinvertebrate assemblage distribution and diversity. Second, based on selected variables and weighted averages, we determined specific family indicator values and assigned pollution tolerance values (varying from 1: tolerant, to 10: sensitive) to a family. Finally, we established four water quality classes: poor, fair, good, and excellent. The RS is highly correlated with the Average Score Per Taxon System (p &lt, 0.05), a well-known and widely used biotic index. The RS has 5 unique taxa that are not included in other regional indices. In this regard, the development of the RS is a beneficial tool for tailor-made biomonitoring that can contribute to the sustainable development of the Rwenzori stream and river basins.

Riparian forest buffers have multiple benefits for biodiversity and ecosystem services in both freshwater and terrestrial habitats but are rarely implemented in water ecosystem management, partly reflecting the lack of information on the effectiveness of this measure. In this context, social learning is valuable to inform stakeholders of the efficacy of riparian vegetation in mitigating stream degradation. We aim to develop a Bayesian belief network (BBN) model for application as a learning tool to simulate and assess the reach- and segment-scale effects of riparian vegetation properties and land use on instream invertebrates. We surveyed reach-scale riparian conditions, extracted segment-scale riparian and subcatchment land use information from geographic information system data, and collected macroinvertebrate samples from four catchments in Europe (Belgium, Norway, Romania, and Sweden). We modelled the ecological condition based on the Average Score Per Taxon (ASPT) index, a macroinvertebrate-based index widely used in European bioassessment, as a function of different riparian variables using the BBN modelling approach. The results of the model simulations provided insights into the usefulness of riparian vegetation attributes in enhancing the ecological condition, with reach-scale riparian vegetation quality associated with the strongest improvements in ecological status. Specifically, reach-scale buffer vegetation of score 3 (i.e. moderate quality) generally results in the highest probability of a good ASPT score (99–100%). In contrast, a site with a narrow width of riparian trees and a small area of trees with reach-scale buffer vegetation of score 1 (i.e. low quality) predicts a high probability of a bad ASPT score (74%). The strengths of the BBN model are the ease of interpretation, fast simulation, ability to explicitly indicate uncertainty in model outcomes, and interactivity. These merits point to the potential use of the BBN model in workshop activities to stimulate key learning processes that help inform the management of riparian zones. Riparian forest buffers have multiple benefits for biodiversity and ecosystem services in both freshwater and terrestrial habitats but are rarely implemented in water ecosystem management, partly reflecting the lack of information on the effectiveness of this measure. In this context, social learning is valuable to inform stakeholders of the efficacy of riparian vegetation in mitigating stream degradation. We aim to develop a Bayesian belief network (BBN) model for application as a learning tool to simulate and assess the reach-and segment-scale effects of riparian vegetation properties and land use on instream invertebrates. We surveyed reach-scale riparian conditions, extracted segment-scale riparian and subcatchment land use information from geographic information system data, and collected macroinvertebrate samples from four catchments in Europe (Belgium, Norway, Romania, and Sweden). We modelled the ecological condition based on the Average Score Per Taxon (ASPT) index, a macroinvertebrate-based index widely used in European bioassessment, as a function of different riparian variables using the BBN modelling approach. The results of the model simulations provided insights into the usefulness of riparian vegetation attributes in enhancing the ecological condition, with reach-scale riparian vegetation quality associated with the strongest improvements in ecological status. Specifically, reach-scale buffer vegetation of score 3 (i.e. moderate quality) generally results in the highest probability of a good ASPT score (99-100%). In contrast, a site with a narrow width of riparian trees and a small area of trees with reach-scale buffer vegetation of score 1 (i.e. low quality) predicts a high probability of a bad ASPT score (74%). The strengths of the BBN model are the ease of interpretation, fast simulation, ability to explicitly indicate uncertainty in model outcomes, and interactivity. These merits point to the potential use of the BBN model in workshop activities to stimulate key learning processes that help inform the management of riparian zones.

Performing biological assessments of freshwater systems is crucial in most tropical rivers as the lack of in-depth knowledge about functional diversity inhibits the design of appropriate water management and restoration plans. Therefore, in this paper, we investigated the presence and evolution of the functional diversity of the macroinvertebrate community along a tropical river. More specifically, 31 locations were sampled in the Portoviejo River (Ecuador) and identified macroinvertebrates were assigned to one of the following functional feeding groups (FFGs): shredders, collector-gatherers, collector-filterers, scraper-grazers and predators. Results show that high fluctuations and relatively low similarity in functional feeding group composition occurred among closely located sites, suggesting the presence of local disturbances. Locations close to the effluent of a wastewater treatment plant show an extreme dominance of scraper-grazers, suggesting elevated nutrient input and algae growth. Further downstream, the interaction of upstream disturbances and local land use influenced the community composition. These interactions and the confirmation of the importance of land use on aquatic communities underline the fact that management should include both taxonomic and functional diversity.

We evaluated the biological water quality in relation to chemicals discharged through sewage outfall during both dry and rainy season. The lowland area of the Cuenca River basin in the southern Andes of Ecuador, including the city of Cuenca, constituted the study area. To perform an integrated water quality assessment, data were collected of macroinvertebrates, physicochemical conditions and morphological characteristics in 43 sites in the Cuenca River and its tributaries. The Andean Biotic Index (ABI) and the Biological Monitoring Working Party adapted to Colombia (BMWP-Col) were used to evaluate the biological water quality. Both biological indexes were higher upstream than downstream from the city. Moreover, these indexes indicated better conditions during the rainy season than in the dry season, based on the presence of more sensitive families. The biological indexes related more to the oxygen saturation than to the five-day biological oxygen demand (BOD5), nutrients and chloride concentrations. The relationship between BOD5 and nutrient concentrations with the variation of both biological indexes was clearer in the dry season than in the rainy season. However, in some sites, these indexes were influenced more by morphological aspects than by pollutants. Both biological indexes showed similar patterns along the rivers, generally the BMWP-Col scored higher than the ABI index. The latter index was shown to be more suitable for the high Andes region. These results could be used to support the implementation of river restoration actions, such as determining priorities for splitting sewer and precipitation water transport systems and needs for improved wastewater treatment facilities in specific locations. © 2018 Elsevier GmbH

This study aims to assess the macroinvertebrate communities, diversity and ecological quality (expressed as BMWP-Viet) of rivers on a tropical island. Environmental factors associated with macroinvertebrate communities, diversity and ecological quality were identified to assist conservation planning and management. Biological (macroinvertebrates), chemical, physical and hydromorphological characteristics of 85 river reaches were assessed in Leyte island, Philippines. Canonical Correspondence Analysis (CCA) and multivariable linear regression (LRM) were performed to relate environmental variables and macroinvertebrates. Several taxa of snails, shrimps, dragonflies, beetles, bugs and caddisflies were found on the island. Although many sites had good to very good ecological quality and high diversity, about 41% had moderate to very bad ecological quality and low diversity. Based on CCA, we can conclude that macroinvertebrate communities were associated with velocity, sediment, conductivity and dissolved oxygen. Particularly, sensitive and tolerant taxa were encountered at high and low flow velocities, respectively. LRM indicated that macroinvertebrate diversity and ecological quality were associated with physical (turbidity), chemical (chlorophyll), hydromorphological characteristics (bank slope & pool/riffle class), habitat degradation (gravel/sand quarrying, erosion) and the presence of logs and twigs. Consequently, this study gives support to the use of invertebrates as indicators of certain environmental conditions and the results of this investigation can serve as a basis to set up dedicated experiments to further prove the causality of these discovered relations. Strikingly, organic pollution, as reflected by biological oxygen demand and chemical oxygen demand, was in general weakly related to invertebrate composition, diversity and ecological quality. This might be linked to the low input in most sites and the relatively short rivers which are closely connected to the marine system. Thus, typical midstream and downstream systems were not encountered and the accumulation of these pollutants along the river is less likely. Although the island is situated in the western Pacific Ocean and encounters intensive natural disturbances (severe typhoons), the taxa (families) are similar to other tropical systems and the effects of the environmental conditions are comparable. Findings of this study are valuable in understanding tropical island systems and provide insights into the effects of environmental conditions on stream invertebrates, which aids in protecting and conserving tropical insular systems.

Water quality modelling is an effective tool to investigate, describe and predict the ecological state of an aquatic ecosystem. Various environmental variables may simultaneously affect water quality. Appropriate selection of a limited number of key-variables facilitates cost-effective management of water resources. This paper aims to determine (and analyse the effect of) the major environmental variables predicting ecological water quality through the application of fuzzy models. In this study, a fuzzy logic methodology, previously applied to predict species distributions, was extended to model environmental effects on a whole community. In a second step, the developed models were applied in a more general water management context to support decision and policy making. A hill-climbing optimisation algorithm was applied to relate ecological water quality and environmental variables to the community indicator. The optimal model was selected based on the predictive performance (Cohen’s Kappa), ecological relevance and model’s interpretability. Moreover, a sensitivity analysis was performed as an extra element to analyse and evaluate the optimal model. The optimal model included the variables land use, chlorophyll and flow velocity. The variable selection method and sensitivity analysis indicated that land use influences ecological water quality the most and that it affects the effect of other variables on water quality to a high extent. The model outcome can support spatial planning related to land use in river basins and policy making related to flows and water quality standards. Fuzzy models are transparent to a wide range of users and therefore may stimulate communication between modellers, river managers, policy makers and stakeholders.

The Sub-Saharan alpine freshwater biodiversity is currently impacted by human settlements, climate change, agriculture, and mining activities. Because of the limited biodiversity studies in the region, a better understanding is needed of the important environmental variables affecting macroinvertebrate assemblages. In this paper, macroinvertebrate diversity responses to 18 environmental variables were studied at 30 sites along unique Rwenzori rivers at the equator in Uganda. We hypothesized that anthropogenic disturbance and local environmental variables affect macroinvertebrate diversity, irrespective of altitudinal gradients. Based on altitude and climate, the sites were subdivided into three altitude groups consisting of 10 sites each: upstream (US) 1400&ndash, 1600 m.a.s.l., midstream (MS) 1091&ndash, 1399 m.a.s.l., and downstream (DS) 900&ndash, 1090 m.a.s.l. A total of 44 macroinvertebrate families and 1623 individuals were identified. The macroinvertebrate diversity patterns were influenced by temperature, altitude, and latitude. Regression analysis revealed that temperature and nickel, were negative predictors of taxa richness. Nickel, which is released by mining activity, is detrimental to aquatic communities in Sub-Saharan alpine ecosystems. Significant longitudinal variation in macroinvertebrate diversity was observed between the sites, which were also affected by mineral and temperature gradients. Our study highlights the need for long-term monitoring in this region to detect and reduce the threats to river biodiversity from anthropogenic activity.

Patches of riparian woody vegetation potentially help mitigate environmental impacts of agriculture and safeguard biodiversity. We investigated the effects of riparian forest on invertebrate diversity in coupled stream-riparian networks using a case study in the Zwalm river basin (Flanders, Belgium). Agriculture is one of the main pressures in the basin and riparian forest is limited to a number of isolated patches. Our 32 study sites comprised nine unshaded &ldquo, unbuffered&rdquo, sites which were paired with nine shaded &ldquo, buffered&rdquo, sites on the same stream reach, along with five &lsquo, least-disturbed&rsquo, sites and nine downstream sites. We sampled water chemistry, habitat characteristics and stream and riparian invertebrates (carabid beetles and spiders) at each site. Three methods were used to quantify riparian attributes at different spatial scales: a visually-assessed qualitative index, quantitative estimates of habitat categories in six rectangular plots (10 &times, 5 m) and geographic information system (GIS)-derived land cover data. We investigated relationships between invertebrates and riparian attributes at different scales with linear regression and redundancy analyses. Spiders and carabids were most associated with local riparian attributes. In contrast, aquatic macroinvertebrates were strongly influenced by the extent of riparian vegetation in a riparian band upstream (100&ndash, 300 m). These findings demonstrate the value of quantifying GIS-based metrics of riparian cover over larger spatial scales into assessments of the efficacy of riparian management as a complement to more detailed local scale riparian assessments in situ. Our findings highlight the value of even small patches of riparian vegetation in an otherwise extensively disturbed landscape in supporting biodiversity of both terrestrial and freshwater invertebrates and emphasize the need to consider multiple spatial scales in riparian management strategies which aim to mitigate human impacts on biodiversity in stream-riparian networks.

The Portoviejo River, located in the central western part of Ecuador, has been heavily impacted by damming, intensive agriculture and untreated wastewater discharge. Unfortunately, detailed information on the water quality and the ecological status of the Portoviejo River is not available, inhibiting decision-making and the development of water management plans. Therefore, the aims of this study were (1) to assess the ecological water quality, (2) to investigate the point along the environmental gradient where the most significant change in macroinvertebrate community occurs and (3) to find potential macroinvertebrate taxa that significantly change in abundance and frequency of occurrence along the Portoviejo River. To this end, macroinvertebrate and physico-chemical data were collected and hydro-morphological conditions were recorded at 31 locations during the dry season of 2015. The results showed that the ecological water quality of the sampling sites ranged from good to bad. In addition, the Threshold Indicator Taxa ANalysis was used to examine changes in macroinvertebrate communities and revealed significant community change points for sensitive taxa declining at a conductivity value of 930 (mu S.cm(-1)) and nitrate-nitrogen concentrations of 0.6 mg.L-1. In addition, the thresholds estimated for tolerant taxa were set at a conductivity value of 1430 mu S.cm(-1) and nitrate-nitrogen concentration of 2.3 mg. L. Atyidae, Corbiculidae, Thiaridae, Acari, Baetidae and Leptohyphidae can be considered indicator taxa, showing shifts in the community. This study suggests that values of conductivity and nitrate-nitrogen concentrations should not exceed the threshold levels in order to protect macroinvertebrate biodiversity in the Portoviejo River.

The Guayas river basin is one of the major watersheds in Ecuador, where increasing human activities are affecting water quality and related ecosystem services. The aims of this study were (1) to assess the ecological water quality based on macroinvertebrate indices and (2) to determine the major environmental variables affecting these macroinvertebrate indices. To do so, we performed an integrated water quality assessment at 120 locations within the river basin. Biological and physical–chemical data were collected to analyze the water quality. Two biotic indices were calculated to assess the water quality with an ecological approach: the Biological Monitoring Working Party Colombia (BMWP-Col) and the Neotropical Low-land Stream Multimetric Index (NLSMI). Both the BMWP-Col and NLSMI indicated good water quality at the (upstream) forested locations, lower water quality for sites situated at arable land and bad water quality at residential areas. Both indices gave relevant assessment outcomes and can be considered valuable for supporting the local water management. A correspondence analysis (CA) applied on both indices suggested that flow velocity, chlorophyll concentration, conductivity, land use, sludge layer and sediment type were the major environmental variables determining the ecological water quality. We also suggested that nutrient and pesticide measurements are important to study water quality in the area where intensive agriculture activities take place. The nutrient levels detected in agricultural areas were relatively low and illustrated that the types of crops and the current cultivation methods were not leading to eutrophication. The applied methods and results of this study can be used to support the future water management of the Guayas river basin and similar basins situated in the tropics.

Food production often leads to environmental degradation. Consequently, insights into ecosystem functioning in relation to exploitation are needed as a basis for socioeconomically acceptable mitigation of these impacts. A Bayesian Belief Network (BBN) model is developed to link three major ecosystem services (ES), i.e. food production, water provision and ecotourism, and determine the effect of local agricultural practices and management on the ES in the Guayas Basin (Ecuador). Several data sources were integrated into the BBN model, including processed spatial data from primary and secondary sources, sampling and survey data, and expert knowledge. The model suggests that banana and sugar cane generate the highest yield but provide low ecotourism benefits. In contrast, cacao produces the lowest yields but contributes to better water quality. Scenario analyses suggest that environmental gains are possible by optimising the land use (LU) based on the edaphoclimatic requirements of crops. Moreover, the integration of LU optimisation with upscaling and farming intensification can allow for additional advantages in water provision and ecotourism while mitigating productivity losses. The BBN development approach can serve as a reference for other case studies, where data scarcity plays a limiting factor in the assessment of interactions between key ES.

The growth of urbanization worldwide has contributed to the deterioration of the ecological status of water bodies. Efforts at improving the ecological status have been made either in isolated form or by means of integrated measures by stakeholders, but in many cases, these measures have not been evaluated to determine their benefit. In this study, we implemented a scenario analysis to restore the ecological water quality in the Cuenca River and its tributaries, which are located in the southern Andes of Ecuador. For this analysis, an integrated ecological model (IEM) was developed. The IEM linked an urban wastewater system (IUWS) model, which gave satisfactory results in its calibration and validation processes, with ecological models. The IUWS is a mechanistic model that incorporated the river water quality model, a wastewater treatment plant (WWTP) with activated sludge technology, and discharges from the sewage system. The ecological status of the waterways was evaluated with the Andean Biotic Index (ABI), which was predicted using generalized linear models (GLMs). The GLMs were calculated with physicochemical results from the IUWS model. Four scenarios that would enhance the current ecological water quality were analyzed. In these scenarios, the inclusion of a new WWTP with carbon, and with carbon and nitrogen removal as well as the addition of retention tanks before the discharges of combined sewer overflows (CSOs) were assessed. The new WWTP with carbon and nitrogen removal would bring about a better restoration of the ecological water quality due to better nitrogen removal. The retention tanks would help to enhance the ecological status of the rivers during rainy seasons. The integrated model implemented in this study was shown to be an essential tool to support decisions in the Cuenca River basin management.

The Guayas River basin is one of the most important water resources in Ecuador, but the expansion of human activities has led to a degraded water quality. The purpose of this study was (1) to explore the importance of physical-chemical variables in structuring the macroinvertebrate communities and (2) to determine if the thresholds in stream velocity related to macroinvertebrate community composition could be identified in the Guayas River basin. Thus, macroinvertebrates and physical&ndash, chemical water quality variables were sampled at 120 locations during the dry season of 2013 in the Guayas River basin. Canonical correspondence analysis (CCA) was performed to identify relevant physical&ndash, chemical characteristics of the river influencing the distribution of the macroinvertebrate communities. Threshold indicator taxa analysis (TITAN) was used to discriminate between the macroinvertebrate community related to stagnant waters (Daule&ndash, Peripa reservoir) and to running waters. CCA indicates that the most important environmental factors influencing the distribution of macroinvertebrate communities were stream velocity, chlorophyll concentration, conductivity, temperature and elevation. Tipping points for the macroinvertebrate community were defined by stream velocity at 0.03 m/s and 0.4 m/s, i.e., stagnant-water (including dam-related reservoirs) taxa start to quickly decrease in abundance and frequency at 0.03 m/s while running-water taxa start to quickly increase in abundance and frequency at 0.03 m/s until a stream velocity of 0.4 m/s. The results provide essential information to define environmental flows to further support water management plans of the Guayas River basin. Information obtained will be useful for management of similar rivers in South America, as well as the rest of the world.

In this study, we assessed the relationship between the occurrence of the invasive water hyacinth ( Eichhornia crassipes ) and water quality properties as well as macroinvertebrate diversity in a tropical reservoir, situated in western Ecuador. Macroinvertebrates and physico-chemical water quality variables were sampled at 32 locations (during the dry season of 2013) in both sites covered and non-covered by water hyacinth in the Daule-Peripa reservoir. The results indicated that, in terms of water quality, only turbidity was significantly different between sampling sites with and without water hyacinth (Mann–Whitney U -test, p U -test, p

Recent studies on water quality in tropical rivers indicate substantial differences between seasons. However, investigations on the needs and added value of season-specific models are lacking. Thus, this paper aims to determine the accuracy and relevance of season-specific and season-overarching models to predict biological water quality. Additionally, we investigated the variation of prediction accuracy using sub-datasets from different parts of the Cuenca River basin. This study was accomplished in the rivers that pass through the urban and suburban areas of the city of Cuenca, which is located in the southern Andes of Ecuador. The Andean Biotic Index (ABI) was used as an indicator of biological water quality. Subsequently, models were developed to predict the ABI, with physicochemical and morphological variables as predictors, which were collected in 43 sites during both the dry and the rainy seasons. The predictions were obtained using three kinds of generalized linear models (GLMs): Gaussian, Gamma and Inverse Gaussian. The season-specific models were more accurate than the season-overarching models. Similarly, the predictions of the biological water quality in sites sampled in the urban area were more accurate than the forecasts performed in reference sites. The major variables predicting the ABI during the dry season were five-day biological oxygen demand (BOD5), ammonium and orthophosphate, while dissolved oxygen (DO), oxygen saturation (OS), nitrate, total solids proved to be important during the rainy season. The results of this research emphasize the importance of developing season-specific models and the implementation of different key actions for river restoration during both the dry and rainy seasons. The accuracy and the replication of these models could be improved and checked with more data taken from new sampling events. The modelling approach developed in this study can be applied to similar basins in the tropics and reveals that environmental investments need to count on monitoring strategies and data and analyses of the biological water quality variation in dry and rainy seasons, within the context of sustainable development.

Worldwide, large investments in wastewater treatment are made to improve water quality. However, the impacts of these investments on river water quality are often not quantified. To assess water quality, the European Water Framework Directive (WFD) requires an integrated approach. The aim of this study was to develop an integrated ecological modelling framework for the River Drava (Croatia) that includes physical-chemical and hydromorphological characteristics as well as the ecological river water quality status. The developed submodels and the integrated model showed accurate predictions when comparing the modelled results to the observations. Dissolved oxygen and nitrogen concentrations (ammonium and organic nitrogen) were the most important variables in determining the ecological water quality (EWQ). The result of three potential investment scenarios of the wastewater treatment infrastructure in the city of Varaždin on the EWQ of the River Drava was assessed. From this scenario-based analysis, it was concluded that upgrading the existing wastewater treatment plant with nitrogen and phosphorus removal will be insufficient to reach a good EWQ. Therefore, other point and diffuse pollution sources in the area should also be monitored and remediated to meet the European WFD standards.

To assess the ecological water quality in Flanders (northern part of Belgium), macroinvertebrates have been collected by the Flemish Environment Agency. During the present study, the blackflies collected between 1997 and 2009 were identified to species level. In total, more than 44,000 specimens were identified, belonging to 12 different species. Sensitive species were restricted to small brooks, while species tolerating lower oxygen concentrations and higher nutrient concentrations were also present in larger watercourses. Several species were either restricted to watercourses in the Campine region (northeast Flanders) or the loamy region (southern Flanders), while the other regions only contained eurytopic species. The prevalence of blackflies increased from less than 5% to almost 30% in the nineties, but did not further increase during the next decade. Habitat suitability models (logistic regressions, artificial neural networks, support vector machines and classification trees) could accurately predict the presence or absence of blackflies. An ensemble forecast, based on predicted oxygen and nutrient concentrations due to planned water quality improvement strategies, predicted that blackflies prevalence will rise to 42% in 2015 and 64% in 2027. Since blackflies only possess a moderate sensitivity, they could occur in all types of running waters with a good water quality. As a good ecological status is required by the European Union Water Framework Directive for all surface waters, it is thus apparent that more efforts will be needed to improve the water quality in Flanders.

Stoneflies are macro-invertebrates that are sensitive water quality indicators. Here, their occurrence was modelled based on physical–chemical water characteristics, river morphology and land use with five different modelling techniques. In a case-study in Flanders, stoneflies were found in 219 samples and two sets of absence data were gathered: 219 random samples from sites without stoneflies and 219 samples from sites downstream of each sampling site where stoneflies were observed. With both random and downstream absences, logistic regressions, artificial neural networks, support vector machines, random forests and classification trees could all successfully predict stonefly occurrence. For most environmental parameters, significant differences were found between sites with and without stoneflies. As stoneflies were only detected in a few percent of the samples, the ecological water quality is obviously still too low in most watercourses. Based on planned water quality improvement measures, an ensemble forecast using the five mentioned modelling techniques predicted that stonefly prevalence will only increase marginally by 2015 and 2027. To meet the European Union Water Framework Directive requirements, which states that all surface waters should obtain a good ecological quality, a more ambitious management plan is needed to decrease nutrient concentrations and improve habitat quality.

The Gilgel Gibe reservoir, which was built to fulfill the energy demand and the electricity export ambitions of Ethiopia, was characterized by low macroinvertebrate diversity mainly due to water level fluctuations, trampling of the littoral zone by cattle, nutrient input, and siltation from the catchment flow. The downstream river system was also affected by the dam due to a strongly decreased discharge as the water is diverted to Gilgel Gibe II hydropower plant through a 25 km underground tunnel. The study was based on seasonal macroinvertebrate sampling, water quality analyses, measurement of daily water level fluctuation, and recording of major anthropogenic activities. Hierarchical cluster analysis and canonical correspondence analysis were performed to determine relationships between the macroinvertebrate community composition and the environmental variables in the reservoir. The cluster analysis, Kruskal-Wallis ANOVA, and MANOVA permutation tests, revealed that differences in physicochemica...

The aim of this study was to predict the future distribution of an invasive macroinvertebrate species, Dikerogammarus villosus, under changing environmental conditions. For this, we used an integrated modelling approach. First, a habitat suitability model (HSM) was constructed on the basis of a regression tree model, to determine the preferred chemical water quality conditions. Subsequently, this HSM was combined with a chemical water quality model that makes predictions on future water quality scenarios for the year 2015 and 2027. It was expected that the area of suitable habitat of D. villosus would increase with improving water quality conditions in the future. Finally, migration speed was incorporated to model the spatial–temporal spread of D. villosus based on a network analysis. On the basis of monitoring data of Flanders (Belgium), it was calculated that D. villosus is able to spread with an average speed of 5 km year−1.The model simulations indicate that the species is primarily present in large rivers and canals with a good chemical water quality. With improving water quality, the species will be able to colonize additional watercourses, mainly because of a decrease in chemical oxygen demand and orthophosphate concentration. A validation based on the observed occurrence shows that the model accurately predicts areas with a high suitability that are most likely to be invaded by D. villosus. Our integrated modelling approach is useful as a practical method to perform risk assessment for watercourses that are vulnerable to invasions not only in Flanders but also in the whole world. Copyright © 2013 John Wiley & Sons, Ltd.

Macroinvertebrates have been collected in Flanders since 1989 by the Flemish Environment Agency to assess ecological water quality. During the present study, the collected waterbugs were identified to species level. In total, more than 90 000 waterbugs were identified, belonging to 45 species. Two of these are recent additions to Flemish fauna: Sigara iactans was found to be a common species in 1989, the first year of monitoring, which is earlier than the first records reported so far, whereas Cymatia rogenhoferi remains a very rare species. Five different communities could be recognized: (1) species occurring in alkaline waters with a high pH, (2) species occurring in colder waters that can tolerate slightly brackish and nutrient rich water, (3) species from running waters, (4) species from acidic waters and (5) ubiquist species that occurred in all types of water. Owing to the general improvement of chemical water quality during the last decade, most species increased, however, three pollution tolerant species declined significantly: Callicorixa praeusta, Corixa punctata and Sigara striata.

The biotic integrity of the Guayas River basin in Ecuador is at environmental risk due to extensive anthropogenic activities. We investigated the potential impacts of hydromorphological and chemical variables on biotic integrity using macroinvertebrate-based bioassessments. The bioassessment methods utilized included the Biological Monitoring Working Party adapted for Colombia (BMWP-Col) and the average score per taxon (ASPT), via an extensive sampling campaign that was completed throughout the river basin at 120 sampling sites. The BMWP-Col classification ranged from very bad to good, and from probable severe pollution to clean water based on the ASPT scores. Generalized linear models (GLMs) and sensitivity analysis were used to relate the bioassessment index to hydromorphological and chemical variables. It was found that elevation, nitrate-N, sediment angularity, logs, presence of macrophytes, flow velocity, turbidity, bank shape, land use and chlorophyll were the key environmental variables affecting the BMWP-Col. From the analyses, it was observed that the rivers at the upstream higher elevations of the river basin were in better condition compared to lowland systems and that a higher flow velocity was linked to a better BMWP-Col score. The nitrate concentrations were very low in the entire river basin and did not relate to a negative impact on the macroinvertebrate communities. Although the results of the models provided insights into the ecosystem, cross fold model development and validation also showed that there was a level of uncertainty in the outcomes. However, the results of the models and sensitivity analysis can support water management actions to determine and focus on alterable variables, such as the land use at different elevations, monitoring of nitrate and chlorophyll concentrations, macrophyte presence, sediment transport and bank stability.

SUMMARY 1. Water quality monitoring data from 10 watercourses and laboratory mesocosm studies were used to assess the potential impacts of the crustacean amphipod invader Dikerogammarus villosus on resident macroinvertebrate assemblage structure in Central European fresh waters. 2. The presence of D. villosus was associated with a decline in the prevalence of many native species, pollution sensitive as well as pollution tolerant, and changes in biotic indices, despite the trends of improved water quality coinciding with the invasion period. A general increase in the prevalence of other invaders was also noted. The potential impacts of D. villosus were substratum dependent, differing between stone, concrete and sand-dominated sites. 3. Mean Multimetric Macroinvertebrate Index Flanders (MMIF) values were marginally lower when D. villosus was present (P < 0.06), as opposed to when other amphipod species or no amphipods were present, despite the improved water quality. Mesocosm studies showed that several macroinvertebrate taxa were completely eliminated in treatments with D. villosus, oligochaete worms, Caenidae mayfly, chironomids and tipulids being particularly vulnerable to D. villosus predation. Biological Monitoring Working Party (BMWP) scores were lower in mesocosms with D. villosus as opposed to the native Gammarus pulex or no amphipods at all. 4. We predict that resident macroinvertebrate assemblages in both Central Europe and Britain will come under increasing pressure as D. villosus invasions progress. Consequently, macroinvertebrate biotic indices, such as the MMIF or BMWP, may need to be revised to account for changes in taxa sensitivities to water quality as well as increased predation and competition.

The Ponto-Caspian amphipod species Echinogammarus trichiatus (Martynov, 1932) was found in Belgium for the first time in June 2009 at two different locations in an artificial lake bordered by two large canals. Adults as well as juveniles were found in small numbers and occurred together with several other Ponto-Caspian species such as Dikerogammarus villosus (Sowinsky, 1894) and Dreissena polymorpha (Pallas, 1771). An identification key to the genus Echinogammarus of inland waters in Western Europe is provided. This first record of yet another new amphipod invader in Belgium demonstrates the continuous introduction of alien species into West European waters.

The focus of the present study was to investigate the mechanisms for the alleviation of Cu toxicity in plants by coexistent cations (e.g. Al(3+), Mn(2+), Ca(2+), Mg(2+), H(+), Na(+), and K(+)) and the development of an electrostatic model to predict 50% effect activities (EA50s) accurately. The alleviation of Cu(2+) toxicity was evaluated in several plants in terms of (i) the electrical potential at the outer surface of the plasma membrane (PM) (Ψ(0)(°)) and (ii) competition between cations for sites at the PM involved in the uptake or toxicity of Cu(2+), the latter of which is invoked by the Biotic Ligand Model (BLM) as the sole explanation for the alleviation of toxicity. The addition of coexistent cations into the bulk-phase medium reduces the negativity of Ψ(0)(°) and hence decreases the activity of Cu(2+) at the PM surface. Our analyses suggest that the alleviation of toxicity results primarily from electrostatic effects (i.e. changes in both the Cu(2+) activity at the PM surface and the electrical driving force across the PM), and that BLM-type competitive effects may be of lesser importance in plants. Although this does not exclude the possibility of competition, the data highlight the importance of electrostatic effects. An electrostatic model was developed to predict Cu(2+) toxicity thresholds (EA50s), and the quality of its predictive capacity suggests its potential utility in risk assessment of copper in natural waters and soils.

Polder lakes in Flanders are stagnant waters that were flooded by the sea in the past. Several of these systems are colonized by exotic species, but have hardly been studied until present. The aim of the present study was: (1) to assess the influence of exotic macrobenthic species on the outcome of the Multimetric Macroinvertebrate Index Flanders (MMIF) and (2) to use classification trees for evaluating to what extent physical–chemical characteristics affect the presence of exotic species. In total, 27 mollusc and 10 macro-crustacean species were present in the monitored lakes of which respectively five and four were exotic. The exclusion of the exotic species from the MMIF resulted in a significant decline of this ecological index (−0.03 ± 0.04; p = 0.00). This elimination often resulted into a lower ecological water quality class and more samples were classified into the bad and poor ecological water quality classes. Single-target classification trees for Gammarus tigrinus and Potamopyrgus antipodarum were constructed, relating environmental parameters and ecological status (MMIF) to the occurrence of both exotic invasive species. The major advantages of using single-target classification trees are the transparency of the rule sets and the possibility to use relatively small datasets. However, this classification technique only predicts a single-target attribute and the trees of the different species are often hard to integrate and use for water managers. As a solution, a multi-target approach was used in the present study. Exotic molluscs and crustaceans communities were modelled based on environmental parameters and the ecological status (MMIF) using multi-target classification trees. Multi-target classification trees can be used in management planning and investment decisions as they can lead to integrated decisions for the whole set of exotic species and avoid the construction of many models for each individual species. These trees provide general insights concerning the occurrence patterns of individual crustaceans and molluscs in an integrated way.

In Flanders (Belgium), treatment systems based on constructed wetlands have been successfully implemented to treat the liquid fraction of separated pig manure, resulting in water that meets the stringent discharge criteria. As these systems have proven their nutrient removal performance, attention has moved towards the concept of biodiversity development from a perspective of Integrated Constructed Wetlands (ICWs). The spontaneous colonization of constructed wetlands with macroinvertebrates was examined to quantify the added biological value presented by a farmyard treatment wetland. In total, 17 taxa were found. The diversity of macroinvertebrates increased along the water treatment path in the system and was higher in summer than in autumn. Several pollution sensitive taxa like Orthetrum, Ischnura, and Cloeon were found at the last basins of the treatment wetland chain. Most species were insects, since their adults can easily aerially colonize these recently constructed systems. Water quality was assessed using the Multimetric Macroinvertebrate Index Flanders (MMIF), and showed a general increase towards the end of the treatment. The MMIF increased significantly with decreasing nutrient levels. ICWs adequately combine the treatment of wastewater with supporting and enhancing biodiversity in agricultural landscapes.

The macrocrustacean community of brackish polder waters in Flanders was investigated based on a twenty year survey comprising 430 biological samples taken at 218 different locations. A clear shift in the gammarid community could be observed. After its introduction, the alien Gammarus tigrinus, originating from North America, reached high abundances and became widely spread in the polder waters within a few years. Simultaneously, a decrease in the prevalence of the indigenous brackish water gammarids G. duebeni and G. zaddachi occurred. However, at the same time a decrease in the salinity of the polder waters also was observed. Uni- and multivariate data analysis revealed a clear difference in the environmental preferences of G. tigrinus, G. duebeni, and G. zaddachi. The alien species preferred lower salinities, lower orthophosphate concentrations, and a higher oxygen concentration compared to the two indigenous species. Besides the decrease in prevalence of the native gammarids, a decrease was also observed in prevalence of two other indigenous brackish water crustaceans: Palaemonetes varians and Neomysis integer. It appears that the decrease in salinity is the most important factor causing the decline of the indigenous gammarids and not the introduction of the alien G. tigrinus.

Macroinvertebrates were sampled from summer 2006 until spring 2008 in the Du River basin in subtropical northern Vietnam. Seventy taxa were identified, which were dominated by aquatic insects, with Diptera, Hemiptera, Ephemeroptera, and Odonata being the orders with the highest diversities. Overall, macroinvertebrate diversity was higher during the wet season at upstream sites, while wide river sites downstream showed a higher diversity during the dry season. Spatial and temporal variations in the macroinvertebrate communities were driven by hydromorphological characteristics and especially by water quality issues reflecting anthropogenic impacts in the river basin. Multivariate analyses using canonical correspondence analysis discriminated between pristine and impacted sites. The caddisfly family Hydropsychidae, the mayfly family Caenidae, and the dobsonfly family Corydalidae were reliable indicators of sites with good ecological status. A relatively small temporal variation was detected in the ...

Benthic macroinvertebrates were sampled in the Chaguana river basin in SW Ecuador in March (wet season) and September (dry season) of 2005 and 2006. Aquatic insects dominated the macrobenthos, with Trichoptera, Diptera, Ephemeroptera, Hemiptera and Odonata being the orders with the highest diversity and Ephemeroptera and Diptera being most abundant. No systematic differences in richness and abundance were observed between dry and wet seasons, which is in agreement with the literature. It is concluded that, in the neotropics, macroinvertebrates can probably be sampled for water quality assessments during the whole year: however, sampling soon after spates should be avoided. Using multivariate analysis, stations could be clustered into three groups based on their macroinvertebrate community composition: sites with low, intermediate and high human impact. Classification trees indicated that stations with low human impact had low conductivities, while stations with high conductivities were characterised as highly impacted if the dissolved oxygen concentration was low and intermediately impacted if the dissolved oxygen concentration was high. Classification trees also indicated that Leptophlebiidae (Ephemeroptera) were characteristic for sites with low impact; in sites with intermediate impact, this family was absent but Hydropsychidae (Trichoptera) were present; when both families were absent, impact was high.

From 2004 till 2008, Diplura were sampled at 96 localities in Belgium. Nine different species of Campodea were collected: Campodea fragilis Meinert 1865, Campodea lankesteri Silvestri 1912, Campodea lubbocki Silvestri 1912, Campodea meinerti Bagnall 1918, Campodea plusiochaeta Silvestri 1912, Campodea remyi Denis 1930, Campodea rhopalota Denis 1930, Campodea staphylinus Westwood 1842 and Campodea wallacei Bagnall 1918. The ordination technique non-metric multidimensional scaling indicated that pH and temperature/humidity were probably the most important variables determining species composition. However, it was remarkable that almost all combinations of species were encountered in the field, often even under the same stone. As no temporal segregations seem to take place, it remains unknown how these very similar species can occur together.