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The acquisition of biodiversity data is of prime importance to perform an efficient ecosystem management and ensure the sustainable provisioning of marine ecosystem services. Recent efforts are enforcing environmental genomic methodologies, especially environmental DNA (eDNA) metabarcoding, as a way forward to document biodiversity in a faster and cost‐effective way. Currently implemented biomonitoring regulations, such as the Marine Strategy Framework Directive (MSFD), rely on benthic macroinvertebrate indicator taxa to compute biotic indices (BIs) values and derive an ecological quality assessment. Recent work demonstrated that targeting those macroinvertebrates remains challenging, because of various technical and biological biases. Instead, bacterial communities’ profiles depicted by eDNA metabarcoding data have been shown to mirror macroinvertebrate communities’ variation and can be used to accurately predict the BI values using supervised machine learning (SML). Other studies showed that functional profiles, as obtained by metagenomic or metatranscriptomic approaches, vary along pollution gradient in aquatic ecosystems, demonstrating their potential as powerful indicators. Here, a 16S bacterial dataset collected in the vicinity of aquaculture sites, impacted by organic enrichment of the sea bottom, was used to generate two set of features consisting in either OTU profiles (taxonomic turnover) or predicted gene content using the tax4fun tool (functional turnover) that uses taxonomic annotations to infer functional capabilities based on evolutionary models. Both datasets were leading to accurate predictive models, with comparative performance. These results indicate that both taxonomic and functional turnovers of bacterial communities encompass powerful indicators that could be leveraged by marine biomonitoring programs.

Rongjiang River, the second largest river system in Guangdong Province, flows through the main urban areas of Jieyang and Shantou cities before reaching the South China Sea. Human activities in the surrounding area pose significant threats to this aquatic ecosystem. The ecological status (ES) of the benthic ecosystem of the Rongjiang River estuary has not yet been conducted using indices based on the macrobenthic fauna, which is important for evaluating environmental health. Here, we used four biotic indices (the AZTI’s Marine Biotic Index (AMBI) and Multivariate AZTI’s Marine Biotic Index (M-AMBI), and taxonomic distinctness indices (average taxonomic distinctness Δ+ and variations in taxonomic distinctness Λ+) to appraise the current ES of benthic communities in Rongjiang estuary. Samples were taken from 11 sampling sites located in six general regions: western aquaculture zones, aquaculture zones, Hanjiang River water channel, Shantou City, Shantou Port, and near the ocean. The benthic ecosystem of this estuary is greatly disturbed: the ES of the aquaculture zones and the sites near the Hanjiang River water channel, Shantou City, and close to the ocean was poorer compared with that of other areas; ES was also poorer in winter than in summer. Generalized linear models revealed that Shannon-Wiener index was negatively correlated with dissolved inorganic nitrogen (p < 0.01), M-AMBI was negatively correlated with temperature and dissolved inorganic nitrogen (p < 0.05 and p < 0.01, respectively), and Λ+ was negatively correlated with pH (p < 0.05). The AMBI, M-AMBI, Δ+, and Λ+ indices were suitable for assessing the ES of the benthic ecosystem in an anthropogenically disturbed estuary.

Evaluation of the ecological quality status (EcoQs) of marine ecosystems is significant for environmental protection and management. In this study, the sensitivity/tolerance-based indices AMBI, M−AMBI and BENTIX and feeding evenness index jFD (feeding-based) were first used to assess the benthic ecological status in the coastal waters of Sanshandao, Laizhou Bay, China, which are affected by multiple anthropogenic pressures, such as shipping, fishing and aquaculture. The results showed that the macrobenthic communities were characterized by sensitive or indifferent species of AMBI ecological groups. Trophic analysis indicated that most of the sampled macrobenthos in this study are surface deposit feeders or carnivores. In general, the benthic ecological quality was “good” or “acceptable”, although the four indices showed some differences in the EcoQs classifications for a given site. The AMBI, M−AMBI and BENTIX have a significant correlation (Pearson test, p

Discrepancies were found between Ecological Status of sediments evaluated though the analysis of macrobenthic community and chemical analyses along a heavily trafficked and contaminated maritime seaway in Tyrrhenian Sea. Chemical analyses showed some sites highly contaminated by PAHs and metals with values exceeding thresholds for Good Chemical status and representing potential toxicological risk for benthic animals. Conversely, macrobenthic communities were highly rich and diverse, with Ecological Status (through M-AMBI) Good and High at each site. Sampling depth, total organic carbon, and total nitrogen were the major factors influencing biotic indices (AMBI, M-AMBI, S, H), even if concentrations of PAHs and metals (V, As, and Fe) contributed in explaining a part of indices variability. Habitat heterogeneity of sampled sites is likely acting as a confounding factor for two reasons: (1) high variability of environmental parameters leads to high richness and diversity, to which M-AMBI is sensitive, and (2) environmental parameters explained part of the variability of indices, together with contaminants. Our results suggested the importance of considering natural variability as a fundamental step of environmental impact assessment, for the correct interpretation of biotic indices.

Monitoring and assessment of benthic communities have been routinely undertaken using morphology-based benthic indices, among which AZTI’s Marine Biotic Index (AMBI) and multivariate-AMBI (M-AMBI), are the most successful worldwide (Borja et al., 2019). They are used officially in routine monitoring in many European countries, where they have been intercalibrated (European Commission, 2018). AMBI has been mirrored by metabarcoding, and the genomic version (gAMBI; Aylagas et al., 2014) has demonstrated to yield results comparable to the morphological version. However, we have so far failed to develop a reliable genomic version of M-AMBI (M-gAMBI), which includes gAMBI, richness and diversity (Aylagas et al., 2018). This is because richness and diversity present very different results in morphological and genomic analyses. Since the multivariate method needs reference conditions, these must be set specifically for M-gAMBI to make its results comparable to those obtained with M-AMBI. To this aim, we started annual surveys in 2018, in 22 sampling locations, in Basque estuaries and coast. We present the results from the first three years of these surveys and discuss the problems faced when developing genomic reference conditions for M-gAMBI. The findings are of paramount importance for managers, since any new method or modification of an existing assessment method, needs to demonstrate that the results obtained when assessing the status are similar to those morphological-based methods, already approved and intercalibrated. Aylagas, E., Á. Borja, N. Rodríguez-Ezpeleta, 2014. Environmental Status Assessment Using DNA Metabarcoding: Towards a Genetics Based Marine Biotic Index (gAMBI). PLoS ONE, 9: e90529. Aylagas, E., Á. Borja, I. Muxika, N. Rodríguez-Ezpeleta, 2018. Adapting metabarcoding-based benthic biomonitoring into routine marine ecological status assessment networks. Ecological Indicators, 95: 194-202. Borja, A., G. Chust, I. Muxika, 2019. Chapter Three - Forever young: The successful story of a marine biotic index. Advances in Marine Biology, 82: 93-127. European Commission, 2018. Commission Decision (EU) 2018/229 of 12 February 2018 establishing, pursuant to Directive 2000/60/EC of the European Parliament and of the Council, the values of the Member State monitoring system classifications as a result of the intercalibration exercise and repealing Commission Decision 2013/480/EU. Official Journal of the European Communities, L47: 1-91.

The present study provides energy density (ED) data and models for four macrobenthic invertebrate genera inhabiting freshwater lotic environments (Baetis, Hydropsyche, Rhyacophila, and Onychogomphus). Samples were collected in the hydrological freshwater network of the Region Friuli Venezia Giulia within different watercourse types (creeks, streams, rivers channels, and ditches), and energy density was directly measured using an adiabatic bomb calorimeter. Measured ED expressed in Joule g(-1) wet weight was strongly and positively correlated with percentage of dry weight (DW%) for all genera investigated (r(2) > 0.9504), allowing to obtain genus-specific predictive models based on the relationship between ED and DW%. Models were validated and showed good predictive power, as 90th percentile of observed percentage errors ranged between 4.23% and 5.18% while medians ranged between 1.32% and 2.83%. ANCOVA disclosed significant differences between the models, as those for Rhyacophila and Onychogomphus differed significantly from the others. The empirical models were used to build a dataset of estimated energy density, to assess the relationship between energy density and ecological status of the monitored riverine systems, assessed in compliance with European and Italian law by the application of four different ecological indices (ICMi, RQE_IBMR, STAR_ICMi, and LIMeco). Information regarding ED levels for freshwater macrobenthic invertebrates is still neglected in biomonitoring programs, but it could be useful to interpret some ecological situations in the context of ecological status assessment, especially in relation to the trophic condition of the investigated riverine systems.

Biotic indices are major tools recommended by the European Directives for assessing the ecological status of marine coastal ecosystems such as Posidonia oceanica meadows. Nevertheless, the multitude of available metrics commonly adopted in the P. oceanica monitoring often provide diverging responses about the health status of the habitat. In this study, we investigated the effectiveness and consistency of a set of 11 indices and descriptors working at different level of ecological complexity of P. oceanica ecosystem (individual, population, community, and seascape), applying them on 13 seagrass meadows of the Ligurian Sea (NW Mediterranean). A new approach, named RESQUE (RESilience and QUality of seagrass Ecosystem), is here proposed and aims to provide a single and comprehensive measure of the ecological status of seagrass meadows. RESQUE is a graphical approach that involves the calculation of both the Relative Area Index (RAI) and the Relative Circularity Index (RCI) starting from a radar chart where all the different values of indices and descriptors are reported after being normalized. The RAI represents a measure of the overall environmental quality, while the RCI constitutes a measure of the consistency among indices and it is assumed as a good proxy of meadow resilience. RESQUE turned out to be an effective method to incorporate all the different indices responses, and allowed integration of relevant information into an overall expression of meadow health. Beyond the ability of merely defining the quality of the Ligurian P. oceanica meadows, this approach displayed a great potential being possibly applicable to other habitats and with ideally infinite combinations of metrics., University of Genoa internal funds (FRA2019, Fondi di Ricerca d'Ateneo), Part of this work received an economic support from University of Genoa internal funds (FRA2019, Fondi di Ricerca d'Ateneo).

This paper aims to compare two foraminiferal based biotic indices generally used to evaluate the ecological quality status (EcoQS): the Foram-AMBI and the Foram Stress Index (FSI). For this purpose, we report the distribution and diversity of living foraminiferal assemblages and the environmental variables from a bathymetric transect in the Southern Adriatic Sea. The two indices agree well with the detected organic enrichment but indicate conflicting EcoQS as the Foram-AMBI detects good environmental conditions, whereas the FSI describes a poor-moderate quality. Many species not assigned (including soft-shelled foraminifera) are to blame for the different results. Also, both foraminiferal-based indices neglect the heavy metal increase encountered in the deepest stations. These findings suggest the need for a more in-depth analysis to improve the ecological status evaluation of marine benthic systems, including other descriptors as chemical pollutants in combination with biotic indices sensitive to organic matter enrichment. ? 2020 Elsevier Ltd

Freshwater ecosystems have been severely damaged worldwide by a multitude of human pressures, such as pollution, nutrient enrichment, damming or overexploitation, and this has been more intense over the past five decades. It is therefore important that the impacts of such stressors can be effectively detected, monitored and assessed in order to provide adequate legislative tools and to protect and restore freshwater ecosystems. The use of aquatic biota to detect, measure and track changes in the environment is often known as freshwater biomonitoring and is based on the premise that the presence or absence of biotic assemblages at a given site reflects its degree of environmental quality. For over a century, since the early pollution-oriented indicators, freshwater monitoring has been developing and testing progressively more complex indicator systems, and increasing the plethora of pressures addressed, using different biological groups, such as benthic macroinvertebrates, macrophytes, fish, phytoplankton and phytobenthos. There is an increasing demand for precision and accuracy in bioassessment. In this Special Issue, five high-quality papers were selected and are briefly presented herein, that cover a wide range of issues and spatial contexts relevant to freshwater biomonitoring.

The monitoring of impacts of anthropic activities in marine environments, such as aquaculture, oil-drilling platforms or deep-sea mining, relies on Benthic Biotic Indices (BBI). Several indices have been formalised to reduce the multivariate composition data into a single continuous value that is ascribed to a discrete ecological quality status. Such composition data is traditionally obtained from macrofaunal inventories, which is time-consuming and expertise-demanding. Important efforts are ongoing towards using High-Throughput Sequencing of environmental DNA (eDNA metabarcoding) to replace or complement morpho-taxonomic surveys for routine biomonitoring. The computation of BBI from such composition data is usually being undertaken by practitioners with excel spreadsheets or through custom script. Hence, the updating of reference morpho-taxonomic tables and cross studies comparison could be hampered. Here we introduce the R package BBI for the computation of BBI from composition data, either obtained from traditional morpho-taxonomic inventories or from metabarcoding data. Its aim is to provide an open-source, transparent and centralised method to compute BBI for routine biomonitoring.

The present study performed in Horten Inner Harbor (southern Norway) shows that foraminifera link the present-day Ecological Quality Status (EcoQS) to EcoQS of former times and, this way, bridge an important knowledge gap concerning determination of reference conditions, even in naturally stressed environments such as transitional waters and oxygen depleted habitats. In Horten Inner Harbor, geochemical data in the oldest deposits showed stable background concentrations for about 200 years (from about 1600 to 1800) before human activity became noteworthy, reflecting ‘good’ to ‘high’ status. Hence, it is reasonable that organisms, which lived in the area during the same nearly un-impacted time interval, represent the biologically defined reference conditions, irrespectively of whether the biotic indices are classified as ‘good’ or ‘bad’. The present paper illustrates, with a conceptual model, how the retrospective foraminiferal biomonitoring method can be used to detect environmental perturbations in estuaries and meet the difficulties of the Estuarine Quality Paradox.

Studies on environmental variables and ecological distribution of ichthyofauna assemblages were conducted in the Calabar River. Surface water and ichthyofauna were sampled in order to provide baseline or reference data on the Calabar River at present as regard its future prospects. Seasonal variation shows significant differences in surface water temperature, pH, DO, BOD, conductivity, TDS and TSS between sampling stations and insignificant differences in heavy metals such as cadmium, chromium, iron and copper between sampling stations. Twenty six species of fish fauna were identified belonging to twenty two families. Mugilidae, Clariidae, Cichlidae, Gobiidae and Sciaenidae were the most abundant for both wet and dry season, while Clupeidae, Bathyclupeidae, Carangidae and Sphyraenidae were low in the wet season but high in the dry season. Chromium, copper, surface water temperature, DO correlate significantly with the presence of E. fimbriata, B. soporator, M. sebae, C. gariepinus, M. loennbergii, C. guentheri and P. babarus. The overall values of biotic diversity indices ranged from 0.0504-0.0745 for Simpson’s Index, 2.770-3.095 for Shannon Index, 2.821-3.105 for Margalef’s Index and 0.8606-0.9498 for equitability. However, the presence of certain fish fauna in polluted and non-polluted parts of the river indicates that they could be used as potential bioindicators in assessment and biomonitoring of the river. The methods used in identifying fish diversity proved their applicability for future studies.

Positive plant interactions have strong effects on plant diversity at several spatial scales, expanding species distribution under stressful conditions. We evaluated the joint effect of climate and grazing on the nurse effect of Croton wagneri, by monitoring several community attributes at two spatial scales: microhabitat and plant community. Two very close locations that only differed in grazing intensity were surveyed in an Ecuadorian dry scrub ecosystem. At each location, two 30 × 30-m plots were established at four altitudinal levels (1500, 2630, 1959 and 2100 m asl) and 40 microsites were surveyed in each plot. Croton wagneri acted as community hubs, increasing species richness and plant cover at both scales. Beneath nurses mean richness and cover values were 3.4 and 21.9%, and in open areas 2.3 and 4.5%, respectively. Magnitude of nurse effect was dependent on climate and grazing conditions. In ungrazed locations, cover increased and diversity reduced with altitude, while grazed locations showed the opposite trend. In ungrazed plots the interactions shifted from positive to negative with altitude, in grazed locations interactions remained positive. We conclude that the nurse effect is a key mechanism regulating community properties not only at microsite but also at the entire community scale.

Potash mining is significantly increasing the salt concentration of rivers and streams due to lixiviates coming from the mine tailings. In the present study, we have focused on the middle Llobregat basin (northeast Spain), where an important potash mining activity exists from the beginning of the XX century. Up to 50 million tonnes of saline waste have been disposed in the area, mainly composed of sodium chloride. We assessed the ecological status of streams adjacent to the mines by studying different physicochemical and hydromorphological variables, as well as aquatic macroinvertebrates. We found extraordinary high values of salinity in the studied streams, reaching conductivities up to 132.4 mS/cm. Salt-polluted streams were characterized by a deterioration of the riparian vegetation and the fluvial habitat. Both macroinvertebrate richness and abundance decreased with increasing salinity. In the most polluted stream only two families of macroinvertebrates were found: Ephydridae and Ceratopogonidae. According to the biotic indices IBMWP and IMMi-T, none of the sites met the requirements of the Water Framework Directive (WFD; i.e., good ecological status). Overall, we can conclude that potash-mining activities have the potential to cause severe ecological damage to their surrounding streams. This is mainly related to an inadequate management of the mine tailings, leading to highly saline runoff and percolates entering surface waters. Thus, we urge water managers and policy makers to take action to prevent, detect and remediate salt pollution of rivers and streams in potash mining areas. © 2017, Page Press Publications All rights reserved.

International audience; The authors investigated the impact of the extension of the El Kantra Channel on the composition and structure of macrobenthic assemblages in Boughrara Lagoon (Gulf of Gabes, Tunisia along with the use of 4 biotic indices (AMBI, BENTIX, M-AMBI and TUBI). Thirteen stations were sampled seasonally in 2012–2013. Forty-one species were found in 2012–2013 not recorded in 2009–2010, including 20 species of polychaetes belonging to the trophic groups of deposit-feeders and carnivores which are expected to increase in areas disturbed by organic pollution. During the survey, we recorded a high fish mortality, essentially caused by the development of harmful algal blooms (HAB) which increased organic matter deposition, thus inducing polychaete development. This seems to weaken the bio-indicating power of biotic indices used here which, paradoxically, classified all sampled stations at a high ecological status. A review of these indices and their applicability to all marine environments is recommended.

According to the Water Framework Directive (Directive 2000/60/CE), assessment methods for the biological quality element benthic invertebrates must include diversity, abundance and proportion of pollution sensitive/indicator taxa as indicative parameters. By one hand, the use of pollution sensitive/indicator taxa (indicator taxa indices) is criticized due to the lack of a reliable methodology to know the level at which indicator species can be well represented in unaffected communities. By the other hand, it is often remarked in the literature that the response of diversity measures may be biased by several methodological constraints. In the last few years, several multimetrics, combining both types of indices, have been proposed with the aim of providing a better picture of the response of benthic communities to disturbance gradients. In order to understand how different responses of diversity measures may affect the responses of multimetric indices, several biotic indices, including diversity measures, indicator taxa indices and multimetrics, were calculated for a set of Mediterranean coastal ecosystems affected by different ranges of organic matter content. Diversity measures did not show monotonic patterns of response to the gradient of organic content, particularly at the low end of its range, while strong correlations were found between indicator taxa indices and this pressure indicator gradient. The multimetric used in the study (M-AMBI) was more correlated with its diversity components (H′ and S) than with its indicator taxa component (AMBI) and, consequently, M-AMBI was always less correlated with the gradient of organic content than AMBI. In Mediterranean coastal water ecosystems naturally poor in sediment organic matter content, indicator taxa indices, such as MEDOCC, BOPA, AMBI or BENTIX, seem to give a more reliable picture of the response of benthic communities to moderate increments of organic content than diversity indices., The authors acknowledge Agència Catalana de L’Aigua, Govern de les Illes Balears, Generalitat Valenciana, Junta de Andalucia, EGMASA (Empresa de Gestión Medioambiental, S.A.), Comunidad Autónoma de la Region de Murcia, Hellenic Centre for Marine Research and the Ministry of Environment and Spatial Planning and the Agency for Environment of the Republic of Slovenia for providing the framework of the case studies and the access to data.

Synthesis indices have been developed in order to implement the Water Framework Directive (WFD) goal of achieving a good ecological status for European waters and so need to be validated and inter-calibrated. This study was conducted in a coastal area under mild organic enrichment from a sewage outfall where no other anthropogenic point source disturbance exists. Results are presented from an integrated assessment in order to test if biotic indices would give a response comparable to that of other descriptors. The study included the analysis of sediment descriptors, stable carbon and nitrogen isotopes in benthic species, benthic community species composition and abundance, and biotic indices. The various groups of descriptors were tested under the null hypothesis of no significant alterations with increasing distance from the outfall. The sediment grain-size, median and total organic matter did not cause rejection of the null hypothesis, in contrast to the sediment redox potential and the stable carbon isotopic composition. The benthic community species composition and abundance and their stable carbon isotopic composition also rejected the null hypothesis. In areas closer to the outfall, the redox potential showed negative values, the macrofauna showed the dominance of opportunistic species and the stable carbon isotope composition showed depletion, in accordance with a terrestrial origin of organic matter. These three independent groups of descriptors diagnosed a coherent alteration scenario associated with organic enrichment. However, the biotic indices failed to reject the null hypothesis. The analysis of the full species composition dataset gave a more reliable picture of the environmental disruption and specific descriptors such as stable isotopes allowed a direct measure of the spatial extent of the organic enrichment. In this study, the biotic indices were not effective in showing benthic alterations associated with the mild organic enrichment despite some being based on species tolerance/sensitivity thresholds to this type of disturbance. Their use caused the loss of essential information and hence impaired the diagnostic capability.

Recently there has been a growing interest and need for sound and robust ecological indices to evaluate ecosystem status and condition, mainly under the scope of the Water Framework Directive implementation. Although the conceptual basis for each index may rely on different assumptions and parameters, they share a common goal: to provide a useful tool that can be used in assessing the system's health and that could be applied in decision making. This paper focuses mainly on benthic community-based, biotic indices. We supply a general overview of several indices premises and assumptions as well as their main advantages and disadvantages. Furthermore, an illustrative example is provided of a straightforward application of benthic index of biotic integrity and benthic condition index. As a reference, their performance is compared to the Portuguese-benthic assessment tool. Limitations of the tested indices are discussed in context of the Mondego estuary (Portugal) case study. http://www.sciencedirect.com/science/article/B6W87-4S38C07-1/1/8a495b1458d35c6ecf614eab10816ca3

The objective of this work was to analyse zoobenthic assemblages in the coastal sector of the Río de La Plata, Argentina, after a petroleum spill. Sampling stations were located in representative sites of various landscapes. Structure, composition, physico-chemical parameters and seasonal changes were recorded in order to assess taxocenosis evolution during the period 1999–2003. Recovery signs were estimated by means of biotic indices and the presence of sensitive species. Tolerant species were dominant in heavily polluted sites, with low diversity and water quality values, according to the biotic indices used. In certain zones, sediment quality remains impoverished, with a visible oil film on the surface. However, during the last sampling, some points showed an increase in biotic indices, pointing to a slight improvement in environmental conditions. Fil: Ocon, Carolina Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología "Dr. Raúl A. Ringuelet". Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología; Argentina Fil: Rodrigues Capitulo, Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología "Dr. Raúl A. Ringuelet". Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología; Argentina Fil: Paggi, Analia Constancia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología "Dr. Raúl A. Ringuelet". Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología; Argentina

1. A large number of ecological indicators have been applied to environmental quality assessment, including taxonomic indices based on one or more biotic elements and eventually environmental variables. Several structural parameters of benthic invertebrate assemblages (i.e. diversity, abundance and proportion of disturbance-sensitive taxa) have been included in the European Water Framework Directive (WFD) to rank the ecological status of the transitional waters. 2. Several macrobenthic biotic indices based on species diversity and sensitivities to anthropogenic disturbance, were proposed as effective tools to answer the requirements of the WFD, however, little is known about the responses of these indices under differing ecological conditions. 3. In the present study patterns of variation of five benthic biotic indices (AMBI, M-AMBI, BENTIX, Engle’s B-IBI, and Paul’s B-IBI) have been compared in eight Mediterranean and Black Sea transitional water ecosystems characterized by different habitat typologies and anthropogenic pressures. 4. Overall, biotic indices provided contrasting responses in terms of environmental quality assessments. Both the Engle and Paul multimetric benthic biotic indices of integrity were developed for North American estuaries and therefore require to be recalibrated for the Mediterranean and Black Sea transitional waters. M-AMBI applied to each habitat typology promises to be more effective, but the high heterogeneity of transitional waters and the lack of reference condition along the European coasts limit its application. Further work is needed to develop a biotic index that provides useful and unambiguous information under different anthropogenic pressures and in different transitional waters.

The Shahid Rajaei Reservoir constructed for various purposes such as drinking water supply. In this context, and also because of the importance of the bloom events and eutrophication process in dams, this paper is to survey the relations between some of physicochemical parameters and phytoplankton composition and density, chlorophyll-a and some water quality indices (Trophic, Saproby, Shannon) using mono and multivariate statistical analysis. Water samples collected from 4 stations during May, June, July, August, September, November and February in 2012-2013. According to the results, the maximum concentration of dissolved inorganic nitrogen, chlorophyll-a, phytoplankton abundance, trophic and saproby indices observed in a month of summer which it was accompanied to the minimum value of species diversity index (Shannon). Pearson analysis revealed direct correlation between abundance of Goniaulax polyedra, Goniaulax digitale and trophic index. In the other words, higher abundance of the two species decreased the water quality. Also based on the PCA analysis, the significant correlation observed between abundance of Cyclotella meneghiniana with Shannon and saproby indices which were negative and positive, respectively. This result indicates to the relation of degradation of water quality with increasing the abundance of Cyclotella meneghiniana. Meanwhile, the presence of the three parameters (abundance of Cyclotella meneghiniana, Shannon and saproby indices) in first component of PCA indicated the important role of Cyclotella meneghiniana and two biological indices in determining of water quality in Shahid Rajaei Reservoir.

12 páginas, 4 tablas, 8 figuras., A comprehensive Mediterranean data set has been used to address 3 questions associated with the use of sensitivity/tolerance based biotic indices to infer the Ecological Quality status (EcoQs) of benthic habitats. Our results showed: (1) a significant effect of the reference database on derived sensitivity/tolerance measure (ES500.05) as well as associated Benthic Quality Index values and derived EcoQs; (2) a lack of correlation neither between BQI and AZTI Marine Biotic Index values nor between BQI and Multivariate-AZTI Marine Biotic Index values; (3) a lack of correlation between the values of the Benthic Habitat Quality Index (index derived from Sediment Profile Imagery) and those of either of the 3 tested biotic indices; and (4) a general agreement between the 3 tested biotic indices in describing the lack of global trend for the EcoQs of the Gulf of Lions despite the occurrence of significant changes in benthic macrofauna composition between 1998 and 2010., This study has been carried out with financial support from the French National Research Agency (ANR) in the frame of the Investments for the future Programme, within the Cluster of Excellence COTE (ANR-10-LABX-45).

International audience; A survey of the macro invertebrates of three brooks harbouring the white-clawed crayfish was conducted in Haute-Vienne department (France). Its aim was to increase our understanding of these ecosystems to help the conservation of A. pallipes. These brooks run through pastoral areas with well-developed riparian vegetation, which offers an important shade. Water temperature, dissolved oxygen concentration, pH, and conductivity fell within the ranges found for this species. A total of 34, 31, 29 taxa and 1502, 1364, 2707 individuals of macrobenthos were collected in Holme, Besque and Bellecombe streams, respectively. Results showed good to very good water quality with IBGN scores ranging from 15 (Bellecombe) to 17 (Holme and Besque), reflecting a limited impact of the anthropogenic disturbances. Taxa diversity were high for Holme and Besque with Shannon index around 3.2, translating a great heterogeneity of habitat and an equilibrated faunal community. Bellecombe showed a limited diversity with Shannon index of 1.42, resulting from the presence of numberous Chironomidae. This brook suffers probably weak organic pollution which could be related to the low water flow observed during the sampling. The similarity test according to Jaccard index showed high percentage of common taxa among ETP (Ephemeroptera-Trichoptera-Plecoptera) between all sites. The high similarity of benthic macroinvertebrate communities could be an useful criteria to identify brooks for restocking purpose.

Legislation obliging the maintenance of ecologically defined quality standards has focused attention on the accuracy of bioassessment metrics. Describing the statistical distribution of ecological indicators, Taylor’s Law (TL) has important relevance to the design and interpretation of bioassessment protocols. Analyzing a detailed UK dataset revealed that most macroinvertebrate indicators were characterized by similar geometric distributions, providing a theoretical imperative to log-transform indicator abundance prior to metric derivation. Evaluating a range of bioassessment metrics revealed a 2–4 fold increase in precision and up to 50% improvement in fidelity compared to standard assessment metrics, based on raw-abundance data. Similar improvement in metric fidelity for North American rivers (up to 60%) indicates the broad biogeographic relevance of this analytical modification. Reducing the risk of misclassifying biological quality for a suite of environmentally contrasting rivers from 80% to 4% emphasizes the benefit that this application of TL could deliver to river management. Requiring no increase in costs and with the potential for retrospective application to historical data, this simple modification is entirely compatible with contemporary assessment practice.

International audience; Biotic indices, which reflect the quality of the environment, are widely used in the marine realm. The Posidonia oceanica seagrass meadow is a benthic sublittoral habitat characteristic of the Mediterranean Sea. The Ecosystem-Based Quality Index (EBQI) is based upon the overall functioning of the Posidonia oceanica ecosystem, from primary producers and the litter to top predators. It is compliant with the Marine Strategy Framework Directive (MSFD) of the European Union (EU). It provides managers with a response that is very different from that of the indices only based upon the key species P. oceanica and a few affiliate species. While the species-based indices are mainly designed for assessing the water quality of a waterbody (e.g. pollution), the EBQI provides a picture of the actual status of the ecosystem functioning, including not only pollution but also the whole range of human impacts, from anchoring to overfishing.

International audience; Lakes can be monitored using different bioindicators, among which phytoplankton and benthic diatoms. We compared these two indicators in Lake Geneva for nutrient assessment. Bimonthly samplings were carried out during one year in the euphotic layer of a pelagic site. In the same time four littoral sites were sampled at 40-50 cm depth. Species compositions and abundances of both bioindicators were analyzed following European standards. Water physico-chemical composition was analyzed at the same time. Seasonal succession of benthic diatom guilds was observed. The dynamics of benthic diatom communities were better correlated to the pelagic chemistry than to the local littoral chemistry. We also observed that in the sampling sites frequently exposed to winds and waves, benthic diatoms showed lower correlations to physico-chemical dynamics, because of an increase of pioneer diatoms abundance adapted to turbulent environment, such sites must be avoided for lake monitoring. Finally, biotic indices calculated with benthic diatoms in wind protected sites showed higher correlations with pelagic nutrient concentration (PO43-) than indices calculated with phytoplankton. This unexpected situation can be explained by differences of temporal variability of chemical and biological compartments. Littoral chemistry changed faster than pelagic chemistry because of rains, diffuse flow from watershed and rivers flowing in the littoral zone whereas pelagic chemistry has a much smoother evolution because it is situated 10 km from the coast. But phytoplankton showed a high temporal variability because of wind influence, which explained the low correlation with the smooth evolution of pelagic chemistry. On the other hand, benthic diatoms from sites protected from the dominant wind, showed a lower temporal variability and were more in synchrony with the smooth evolution of pelagic chemistry. Even if we show that diatom seem to be promising indicator of nutrient level of the lake, we also underline the complementarity of using both indicators: benthic diatom and phytoplankton. Each of them brings different information about temporal variability of the lake and about the functioning of different habitats. Comparing these two bioindicators only on the basis of nutrient correlation ability would be an over-simplification whom managers must be warned.

Aquatic ecosystem biomonitoring tools are largely lacking for many developing countries, resulting in adoption of tools developed from other countries/regions. In many instances, however, the applicability of adopted tools to the new system has not been explicitly evaluated. The objective of this study was to test the applicability of foreign diatom-based water quality assessment indices to urban streams in Zimbabwe, with the view of stimulating research to develop improved approaches for assessing ecological integrity of lotic systems in the country. The study evaluated the relationship between measured water quality variables and diatom index scores. The study found a high degree of concordance between water quality variables and diatom index scores. Thus, the indices proved useful in providing an indication of the quality of the investigated waters. This could be attributed to the occurrence of many widely distributed diatom species that have similar environmental tolerances to those recorded elsewhere. Diatom indices which exhibited consistent classifications and strong correlations with water quality variables such as Trophic Index, Saprobic Index, Pampean Diatom Index, Biological Index of Water Quality and Leclercq Index are recommended for use in the country. However, ecological requirements of some diatom species from Zimbabwe need to be clarified and incorporated in a diatom-based water quality assessment protocol unique to the country. Keywords : biological monitoring, pollution, benthic diatoms, biotic indices

Within the European Water Framework Directive, many studies have been conducted to evaluate the sensitivity/robustness of a variety of indices in relation to natural or anthropogenic disturbance events. However, these indices have rarely been applied to verify the impacts of disturbances in offshore environments, though the Marine Strategy Framework Directive recommends their use for assessing benthic community conditions and functionality. The aim of this paper was to determine which biotic indicator performed the best for detecting the impacts of offshore structures on benthic populations in the Adriatic Sea. The impacts of four rigs were investigated six months after their installation, and the H?, AMBI, m-AMBI, BENTIX, and BOPA indices were assessed. Although these five indices delivered some contradictory results because of the differences in their structure and discrepancies in their assignment of species sensitivity, the BENTIX, H? and BOPA indices appear to evaluate stress levels better than the AMBI and m-AMBI indices, which tend to provide results that are slightly overly optimistic. © 2014 Elsevier Ltd. All rights reserved.

Intertidal off-bottom oyster culture is shown to cause organic enrichment of the shore and although there are two stressors of interest (the presence of a structure, the trestles, and also the sediment and organic waste from the oysters), these can be separated and their relative impacts determined using an appropriate nested experimental design and data treatments. Although no artificial food sources are involved, the oysters feeding activity and intensity of culture enhances biodeposition and significantly increases the sediment fines content and total organic matter. This in general impoverished the benthic community in culture areas rather than a species succession with the installation of opportunists or a resulting increase in the abundance and biomass of benthic species; the findings can be a direct consequence of the intertidal situation which is less-amenable recruitment of species more common to the subtidal environment. Thus the most appropriate biological descriptors to diagnose the effects associated with the organic enrichment were the multispecies abundance data as well as the primary biological variables species richness and abundance. The effects were however spatially and statistically significantly confined to the area located directly underneath the culture bags compared to the corridors located between the trestles, which do not show such enrichment effects. Synthesis biotic indices were much less effective to diagnose the benthic alterations associated with this organic enrichment. These results show that special attention must be paid when using indices in areas where the organic enrichment induces an impoverishment of the benthic community but not necessarily a species replacement with the installation of opportunists.

Without industrial and urban development and their effects on marine ecosystem, due to high biotic potential, Khure-Mussa would be one of the productive coastal areas. Because of sensitivity and vulnerability to environmental changes this area are classified in sensitive ecologic area. This study was conducted to evaluation ecological health status in Khure-Mussa in the Northwest of Persian Gulf by using benthic indices. Twenty creeks in Khure-Mussa area were set up for study and sampling in four seasons from winter 2008 to autumn 2009. Monthly water sampling for physico-chemical parameters was done by bottle sampler and seasonal samples of surface sediment were collected by Peterson grab sampler (0.125m^2) .At each station three samples for macrobenthic study and one sample for grain size analysis and organic matter determination were obtain. Totally, 187589 macrobenthic individual were collected and separated. Among identified groups, Polychaetes with total number108906, Crustacean with total number 46561, Bivalve with total number 14156 and seapen with total number 9841 were the dominant groups and were included 58, 25, 8 and 5 percentage of total number respectively. The highest abundance in the spring and the lowest abundance in the summer were observed. According to mean abundance, Somaily creek and Khure-mussa (3) station showed the highest and the lowest abundance respectively. Seapen is included more than 90 % of total biomass. The range of Shannon diversity index was (1.95-3.58) which the minimum and the maximum values were found in Shipping and Patil station respectively. Significance benthic biological parameters (abundance and richness) in different creeks explained the variation of benthic community structure in studied creeks. In addition, seasonal significant differences were found in these parameters due to seasonal changes in benthic animal s succession. The results of grain size analysis showed that the range of siltclay was (63.6-95.59). According to AMBI index values, all of the studied creeks are classified in slightly pollution level and disturbed condition except for Petrochemical station that placed in moderate pollution level. The BOPA index values in all stations showed more than threshold level (0.19) that means bad and weak ecological condition. The highest and the lowest ITI index values were observed in Oil exporting port station (64.92) and Ghazaleh creek (29.53) respectively. The others were grouped in 30-60 range that means moderate pollution level and disturbed ecological status. The values of ABC (Abundance Biomass Curve) that explained the relation between macrobenthic biomass and abundance, were calculated near zero from 0.1 to -0.1 in all studied creeks that show moderate condition for living animals. In general the studied creeks showed pollution potential and benthic biological parameters indicated downward trend in ecological quality and health status.

Transitional waters (TWs) provide ecosystem goods and services that are essential for the well-being of human populations. These unpredictable aquatic systems, characterised by large environmental fluctuations, are under severe stress due to human activities. Increasing pressures (e.g. over-harvesting, eutrophication, habitat loss) inevitably lead to the degradation of these ecosystems. Analysis of the complexity of species distribution patterns within and among TW habitats is relevant to understanding the underlying processes and promoting appropriate management strategies. Assessment of the trophic status is one of the most critical aspects of TWs. Untangling the relevance of anthropogenic nutrient inputs from internal biogeochemical processes is of primary importance in defining appropriate restoration strategies. Biotic indices have been suggested as an operational tool to assess environmental quality in TWs. However, the application in TWs of indices developed for coastal waters can give distorted results (e.g. low species diversity and high abundance are natural features). The BITS approach provides a rapid assessment of ecological quality, although its sensitivity in reflecting field conditions remains to be assessed. The major challenge to TWs management is to couple long-term conservation with productive activities. This goal can be achieved using an integrated approach, forecasting conservation ofTW ecosystem functioning together with sustainable economic development. North-western Adriatic TW habitats have been exploited for centuries and major shifts in ecological processes have occurred. In this study, knowledge of the ecological features of these habitats is summarised and analysed using recent ecological tools. Based on these findings, possible strategies for conservative management have been discussed.