Freshwater Macroinvertebrates: Main Gaps and Future Trends

Freshwater macroinvertebrates play a crucial role in linking sediments and their processes to the food web. Indeed, environmental modifications (e.g., nitrogen deposition, salinity, and temperature increase), pollution (e.g., pesticides and heavy metals), and introduction of alien species are the main drivers of changes that are affecting their communities. This Special Issue aims to present the past and present knowledge on freshwater macroinvertebrates to understand their role as providers of ecosystem services, to highlight the effects of global changes on their community (in the short and long term), and to underline major gaps in their study. Finally, in order to tackle the currently unsustainable use of freshwater natural capital, we welcome ideas and expert opinions on the development of future research linked to national and international regulations

Intercalibration of national methods to assess the ecological quality of rivers in Europe using benthic invertebrates and aquatic flora

The European Water Framework Directive (2000/60/EC) commits the Member States of the European Union to classify the ecological status of their surface waters using biological assessment methods. The harmonisation of the good ecological status between Member States is done in the intercalibration exercise. This doctoral thesis comprises the analysis of basic intercalibration approaches and includes results of the first intercalibration phase. In Chapter 1 the direct comparison of invertebrate-based methods is explored. By means of correlation analyses various biological indices are matched for eight countries sharing two common stream types. The outcomes reveal strong relationships between methods, but deviating definitions of the good ecological status. Supportive environmental data is used to illustrate the level of anthropogenic pressure associated with the respective good-moderate boundary of each national method. In search of the most suitable way for comparing national classifications two differing intercalibration options are studied in Chapter 2. The results show that national macrophyte methods are conceptually different: Divergences in the detection of pressures (nutrient enrichment versus unspecific stresses) and the definition of the natural reference state become evident. Chapter 3 identifies the similarities of national methods to establish common grounds in macrophyte intercalibration. The method comparison is enabled by delineating indicator taxa that are used in a common metric for macrophytes. Chapter 4 includes the comparison of ecological classifications for five Eastern European countries. Common metrics are applied in the intercalibration of national methods using benthic diatoms and invertebrates. Since the availability of data from undisturbed reference sites is generally scarce, an alternative approach based on sites impacted by similar levels of disturbance is employed. The biological benchmarks derived from these sites set transnational reference points for the harmonization of national status classifications

Intercalibrating the national classifications of ecological status for very large rivers in Europe: Biological Quality Element: Benthic invertebrates

The European Water Framework Directive (WFD) requires the national classifications of good ecological status to be harmonised through an intercalibration exercise. In this exercise, significant differences in status classification among Member States are harmonized by comparing and, if necessary, adjusting the good status boundaries of the national assessment methods. Intercalibration is performed for rivers, lakes, coastal and transitional waters, focusing on selected types of water bodies (intercalibration types), anthropogenic pressures and Biological Quality Elements. Intercalibration exercises were carried out in Geographical Intercalibration Groups - larger geographical units including Member States with similar water body types - and followed the procedure described in the WFD Common Implementation Strategy Guidance document on the intercalibration process (European Commission, 2011). The Technical reports are organized in volumes according to the water category (rivers, lakes, coastal and transitional waters), Biological Quality Element and Geographical Intercalibration group. This volume addresses the intercalibration of the Very large river Benthic invertebrate ecological assessment methods. Nineteen countries (Austria, Belgium (Flanders), Bulgaria, Croatia, Czech Republic, Estonia, Finland, Germany, Hungary, Latvia, Lithuania, the Netherlands, Norway, Poland, Romania, Slovakia, Slovenia, Spain and Sweden) participated in the intercalibration exercise and harmonised their benthic invertebrate assessment systems. The results were approved by the WG ECOSTAT and included in the EC Decision on intercalibration (European Commission, 2018).JRC.D.2-Water and Marine Resource

Spatio-temporal dynamics of undisturbed macroinvertebrate communities in the Mondego River basin : contribution to the ecological assessment of streams

Tese de doutoramento em Biologia (Ecologia), apresentada à Universidade de Lisboa através da Faculdade de Ciências, 2008Macroinvertebrates have become the most commonly used and widely known biological indicators for assessing and monitoring human impacts in streams because they respond predictably to many kinds/intensities of anthropogenic pressures. Hence, they were included in the indicators group of ecological status required by the Water Framework Directive (WFD). However, the lack of understanding about natural spatio-temporal variations of macroinvertebrate communities and the lack of taxa lists for many undisturbed lotic systems most certainly hinder streams condition bioassessment, the successful restoration of the natural structural and functional integrity of an ecosystem, and the prediction of climate change impact on freshwater biodiversity. Spatio-temporal dynamics of undisturbed macroinvertebrate communities of the Mondego River basin (MRb) were analysed showing a strong variation both spatially and temporally. These variations were regulated through a multiplicity of factors operating at local [substrate type and hydraulic conditions (current speed, dissolved oxygen)] and larger spatial scales [streambed geology (inferred by conductivity), altitude and channel width]. Seasonal variation of these communities was more similar to that in other Mediterranean streams rather than that in northern temperate Portuguese streams, where seasonality is not as evident. Physical stream types of the MRb (based on the WFD system-B national typology) were tested for biological meaning and showed significant relevance for macroinvertebrates. However, spatial and temporal heterogeneity of abiotic conditions might hinder bioassessment since temporal variations and intermittency do not seem to be incorporated in typology results. Particular emphasis was given to high altitude intermittent streams (above 1400 m a.s.l.), where new chironomid species records were found for continental Portugal and the Iberian Peninsula and the loss of macroinvertebrate biodiversity is expected to occur based on climate change predictions. Also, a protocol to help selecting near-natural stream sites was developed and tested. Finally, the present work raised the need for long term studies, for more information concerning intermittent streams, for molecular studies to solve and complement the lack of taxonomical knowledge and for cross-linking reference conditions and climate change.Fundação para a Ciência e Tecnologia e ESF no âmbito do III Quadro Comunitário de Apoio pela a atribuição da bolsa individual SFRH/BD/6365/2001

Understanding biological responses to degraded hydromorphology and multiple stresses. Deliverable 3.2 of REFORM (REstoring rivers FOR effective catchment Management), a Collaborative project (large-scale integrating project) funded by the European Commission within the 7th Framework Programme under Grant Agreement 282656

The aim of this deliverable is to conceptually model and empirically test the response of biota to the effects of both hydromorphological pressures acting in concert with one another or with other types of pressures. Best use is made of existing large national monitoring datasets (Denmark, UK, Finland, France, Germany, Austria & WISER datasets), case studies and modeling to provide evidence of multiple stressors interacting to alter river biota (Biological Quality Elements: BQE)

Effect-based analyses as tools to assess the impact of differently treated effluents on fish and aquatic ecosystem health

Many surface waters are suffering from anthropogenic pressures, including pollutant emissions. Anthropogenic substances enter the aquatic environment through various pathways with wastewater treatment plants belonging to the most important sources. The technologies that are presently used in conventional wastewater treatment often fail to remove all substances. Consequently, numerous compounds are continuously discharged via effluents into surface waters, where they can be detected on a regular basis. Many studies revealed that traces of chemicals, so-called micropollutants, may pose a considerable threat to aquatic organisms. These findings led to the development of different strategies to reduce trace substances in surface waters, ranging from source control to so-called “end-of-pipe” strategies. One important measure is the expansion of conventional wastewater treatment plants by additional purification steps. Here, removing substances via adsorption to powdered activated carbon is a promising approach for large-scale application. Yet, little is known about the efficiency of this purification process with respect to ecosystem health. In my doctoral thesis, I used effect-based analyses to characterize the effect of differently treated wastewater effluents on fish health. For this purpose, I combined in situ exposure of rainbow trout at two conventionally equipped wastewater treatment plants with subsequent biomarker analyses. In addition, the present thesis includes studies conducted in the context of the research project SchussenAktivplus, which aimed to examine the effect of expanding a wastewater treatment plant by an additional powdered activated carbon stage on the ecosystem of the receiving river Schussen. For this, a comprehensive approach combining different chemical and biological analyses prior and subsequent to the implementation of the additional purification stage was adopted. My studies showed that fish health can be considerably impaired by discharges of conventionally equipped wastewater treatment plants. An additional adsorption stage significantly reduced micropollutant loads in the effluent and thus mitigated the adverse effects in exposed fish. Moreover, this positive effect was also reflected on other levels of biological organisation, thus showing the benefit of wastewater treatment plant upgrading. However, during my studies, adverse effects could sometimes also be detected in fish exposed at the reference site located upstream of the respective wastewater treatment plant. Thus, the degree of adverse reactions in exposed fish was not only linked to the type of wastewater treatment. The general water quality of the receiving river, which also depends on pollution inputs upstream of the wastewater treatment plants under investigation, and the composition of the raw wastewater also seemed to play an important role. Hence, the local conditions should be taken into account when decisions on the necessity and the type of wastewater treatment plant upgrading have to be made

The influence of signal crayfish on fine sediment dynamics and macroinvertebrate communities in lowland rivers

The spread of non-native species is a global threat and the rate at which biological invasions occur is likely to increase in the future. This thesis examines the implications of the invasive signal crayfish, Pacifastacus leniusculus (Dana), for instream communities and abiotic processes within lowland rivers in England. The potential effects on lotic macroinvertebrate communities and fine sediment dynamics are investigated at a range of spatial and temporal scales, from the examination of national long-term datasets through to short-term detailed mesocosm experiments. Interrogation of macroinvertebrate community data from three English regions was undertaken to understand the temporal and spatial extent of signal crayfish effects. Invasive crayfish had significant long-term and persistent effects on resident macroinvertebrate communities regardless of the lithology or other environmental characteristics of the region. The resultant modifications to community composition had repercussions for several widely employed freshwater biomonitoring tools which employ faunal abundance in their derivation. A reach-scale field study was undertaken at two sites, one invaded by crayfish and one which did not support populations of crayfish (control), to assess the potential contribution of signal crayfish for fine sediment dynamics (ingress, fluxes and ultimately the overall implications for sediment budgets). Reach-scale field experiments examining the effect of crayfish invasion on resident macroinvertebrate communities over a 126-day period indicated that once crayfish populations are well-established their effects are persistent. However, separating the effects of crayfish from wider macroinvertebrate community dynamics and life-history characteristics of the invader and resident taxa means that attributing the effects is far from clear. The thesis presents the results of a series of novel mesocosm experiments which examined the dynamic and two-way interactions of predator-prey relationships and potential zoogeomorphological effects of signal crayfish and the freshwater shrimp, Gammarus pulex. Signal crayfish had a significant effect on the mass of fine sediment infiltrating into the gravel matrix associated with foraging and predatory activity; however this was strongly controlled by prey availability. Finally, through the development of conceptual models, the thesis illustrates the need for greater integration of ecological and geomorphological theories, at relevant environmental scales (temporal and spatial) to achieve truly interdisciplinary research

XXXV Congress of the International Association of Hydrogeologists, Groundwater and Ecosystems – Abstract Book

Resumos das comunicações do XXXV Congresso da Associação Internacional de Hidrogeólogos (IAH