High Ecological Status Research Articles

An experimental approach to estimate uncertainty of diatom community analysis in the accreditation process

Diatoms, belonging to the class Bacillariophyceae, are one of the biological elements required for ecological quality status (EQS) assessment according to the Water Frame Directive.Italy has adopted the Intercalibration Common Metric index (ICMi) to evaluate the EQS using diatoms. Developed through the InterCalibration exercise and validated at the European level, the ICMi still presents uncertainty elements related to ecological, spatial and temporal heterogeneities.Quality control assurance has become necessary for ecological tests due to their importance in data acquisition during monitoring activities.The aim of this work was to describe the approach used for the measurement of sampling and/or laboratory phase uncertainty associated with ICMI according to ISO/IEC 17025. Following ISO recommendations, we adopted the “top-down” approach to evaluate uncertainty from repeatability using experimental data.The study was designed to determine the variability of the method in relation to both the sampling and laboratory phases. The approach consisted of analyzing three samples, each with Bad, Moderate or High ecological quality status, ten times, plus ten replicates of sampling from the Moderate status site. Sampling, treatment, analysis, identification and counting were performed according to standard procedures. The ICMi was calculated for all samples.The experiment was performed under the following repeatability conditions: same operator, microscope and iconographic guides. We obtained a standard deviation of repeatability in each series. This study is an attempt to quantify, for the first time, the variability of the diatom analysis process through the value of the ICMi, trying to reduce at least the main sources of errors (identification and counting). It represents an approach to be followed for the accreditation process of a diatom-based laboratory test method according to ISO/IEC 17025.

Ecosystem Service Assessments in Water Policy Implementation: An Analysis in Urban and Rural Estuaries

Coastal waters provide a wide range of ecosystem services (ES), but are under intensive human use, face fast degradation and are subject to increasing pressures and changes in near future. As consequence, European Union (EU) water policies try to protect, restore and manage coastal and marine systems in a sustainable way. The most important EU directive in this respect is the Water Framework Directive (WFD) (2000/60/EC). Objective is to reach a 'good status' in EU waters, following a stepwise and guided process. Our major objective is to test how an ecosystem service assessment can support WFD implementation in practice. We use the Marine Ecosystem Service Assessment Tool (MESAT) that utilizes spatial definitions, reference conditions and the good status according to the WFD as well as data and information gained during the implementation process. The data-based tool allows comparative analyses between different ecological states and an evaluation of relative changes in ES provision. We apply MESAT to two contrasting systems in the German Baltic Sea region, the rural Schlei and the urban/industrialized Warnow Estuary. These data-based assessments show how the ES provision has changed between the historic, pre-industrial state around 1880 (reference conditions with high ecological status), the situation around 1960 (good ecological status), and today. The analysis separates the estuaries into water bodies. A complementary expert-based ES assessment compares the situation today with a future scenario ‘Warnow 2040’ assuming a good ecological status as consequence of a successful WFD implementation. Strengths and weaknesses of the approaches and their utilization in the WFD are discussed. ES assessments can be regarded as suitable to support public relation activities and to increase the acceptance of measures. Further, they are promising tools in participation and stakeholder processes within the planning of measures. However an ES assessment not only supports the WFD implementation, but the WFD provides a frame for ES assessments larger scale assessments in seascapes, increases the acceptance of the ES approach and the readiness of stakeholders to get involved.

Limno-ecological assessment of Aras River surface waters in Turkey: application of diatom indices.

This study is the first attempt to evaluate the limno-ecological status of freshwater ecosystems in Aras River system (Turkey) using diatom metrics and multivariate analyses according to the European Union Water Framework Directive requirements. Samples were collected using the standard protocols from 17 sampling stations in August and October of 2014, and June of 2015. Deterioration of water quality in the Aras River catchment was remarked from the downstream of Karakoyunlu, Sarısu, and Bozkuş creeks, which showed higher values of trophic index Turkey (TIT), trophic index (TI), and eutrophication and/or pollution index-diatom (EPI-D). These sites were also characterized by pollution tolerant taxa e.g., Cocconeis placentula, Gomphonema parvulum, Navicula cryptocephala, Navicula trivialis, and Tryblionella angustata. Sites S14-S17 had high ecological status according to TIT, supported by the score of EPI-D which indicated a good ecological condition for S14. The occurrence of pollution-sensitive species (e.g., Hannaea arcus, Cymbella affinis, Didymosphenia geminata, Meridion circulare, and Encyonema silesiacum) and the low nutrients like total phosphorus, orthophosphate and nitrate, conductivity, and BOD5 supported the high ecological status of S14-S17. The relationships between diatom assemblages and environmental variables were also illustrated by multivariate analyses. Spearman correlation analysis revealed that TIT had positive important correlations with total phosphorus (p < 0.01, r = 0.768). Trophic index and EPI-D had also significant correlations with environmental variables, but they had lower correlation coefficient than that of TIT. It seems that TIT could be a suitable diatom metric for assessing the ecological status of sampling stations in Aras River system and Mediterranean region. Our findings showed also that ecological statuses of surface waters should be evaluated due to the indices developed in their ecoregions.

Bio-assessment of surface waters in the south-east of Gaziantep (Turkey) using diatom metrics

Diatom metrics can be used to identify the ecological status of water bodies due to their good responses to anthropogenic disturbances. Our study is aimed to use diatom metrics developed from different ecoregions for assessing the ecological status of 11 surface waters in the south-east of the Gaziantep catchment (Turkey). Ecological characterizations of the sampling stations were introduced by Trophic Index Turkey (TIT), Trophic Index (TI), and Eutrophication and/or Pollution Index-Diatom (EPI-D). According to TIT and TI, Karkamış Reservoir had a good ecological condition while it had high ecological status based on EPI-D. This good ecological condition was approved by the presence of pollution sensitive species (e.g.,Cymbella affinis,Encyonema minutum,E. silesiacum,Cymbopleura amphicephala, andNavicula radiosa) and relatively low nutrients. Kayacık (TIT ranging 3.15–3.23) and Hancağız (TIT = 3.35) reservoirs had poor and bad ecological conditions, respectively. High nutrient, conductivity, and pollution-tolerant species (e.g.,Nitzschia amphibia,N. palea,N. umbonata,N. linearis,N. phyllepta,Tryblionella calida, andPinnularia brebissonii) supported the ecological statuses of the Hancağız and Kayacık reservoirs. The first two axes of canonical correspondence analysis explained 0.943 of relationships between diatom species and explanatory variables. Explanatory variables,e.g., calcium, conductivity, orthophosphate, nitrate, nitrite, sodium, pH, and sulfur, had strong impacts on the distribution of diatom assemblages among the sampling stations. TIT and TI separated ecological statuses of sampling stations in the south-east of the Gaziantep catchment, which correlated well with the evidence of water chemistry and response of diatom assemblages.

A BIOLOGICAL WATER QUALITY ASSESSMENT BASED ON PHYTOBENTHOS AND MACROINVERTEBRATES AT THREE STATIONS ON THE RIVER NERETVA

UDK: 556.115:574.587(282.249 Neretva)&#x0D; This paper presents the research results of benthos community (phytobenthos and macroinvertebrates) on three locations of the Neretva River: Glavatičevo, Žitomislići and Višići. According to typology of rivers, the site Glavatičevo belongs undertype 10a, while sites Žitomislići and Višići are undertype JIVT (heavily modified water bodies). Research of the benthos community has been done in December 2016 with the simultaneous monitoring chemical parameters of water. All research states showed a great number and a high diversity of benthic taxa, although sampling was spent in December. The saprobic values of benthos community at the site Glavatičevo indicates to oligosaprobic level, the water unloaded with organic substances. The site Žitomislići points to oligo/betamesosaprobic level, the water a bit loaded with organic substances. The site Višići according to phytobenthos demonstrates to oligo/betamesosaprobic level, while according to benthic macroinvertebrates point to betamesosaprobic level (the water loaded with organic substances). Based on saprobic values and chemical parameters of water in keeping with The decision on the characterization of the surface and underground water, reference conditions and parameters for the detection of water state and water monitoring (Official newspapers FBiH, No. 1/14), a maximum ecological potential has been registered on sites Žitomislići and Višići, while a high ecological status has been registered on the site Glavatičevo.

Ecological quality assessment of running waters in the North Aegean catchment with diatom metrics and multivariate approach

Assessing ecological quality of surface waters is getting more important to achieve environmental sustainability since the implementation of EU Water Framework Directive. This study was designed to assess ecological quality of freshwater bodies in the North Aegean catchment using the trophic index Turkey (TIT), recently developed for Turkish running water assessment. This first work attempts to evaluate rivers water quality in the Northern Aegean catchment, a touristic region based on the diatom index dedicated to the Anatolia region. Data were taken from 18 sampling stations in the Northern Aegean catchment (Turkey) from August 2014 to August 2015. A canonical correspondence analysis (CCA) performed to evaluate the relationship between diatom assemblages and environmental variables especially nutrients, temperature, electrical conductivity, and biochemical oxygen demand played important roles in the distribution of diatom species. CCA explained 12.5% of the cumulative percentage variance of diatom assemblage’s data with 92.8% of the species-environment correlations. In related to the water ecological status, the lowest TIT (1.57) values was recorded in Geyikli creek, whereas the highest TIT (2.82) was calculated in Bakırçay stream. The ecological quality ratio changed between 0.58 (Bakırçay stream with moderate status) and 0.99 (Geyikli, Kar and Kemer creeks with high status). Pollution tolerant species such as Gomphonema parvulum, Navicula recens, Navicula cryptocephala, Navicula cryptotenella, Navicula trivialis, and Cyclotella meneghiniana characterized the moderate ecological status water bodies were, while the high and good ecological status sites were characterized by nutrient sensitive species such Navicula radiosa, Didymosphenia geminata, Cymbella excisa, and Hannaea arcus. The ecological status the water bodies indicated exactly the state of deterioration of these watercourses due to human activities in the catchment. A significant positive correlation between TIT values and logTP confirmed that this index as a metric is a useful biological tool for the bioassessment of regional water quality.

Contrasting yield responses to phosphorus applications on mineral and organic soils from extensively managed grasslands: Implications for P management in high ecological status catchments

AbstractPhosphorus (P) loss from grassland production is one of the main causes affecting high status water bodies in Europe. Soils with a high content in organic matter (OM), even if extensively managed, are particularly vulnerable to P losses due to their poor P sorption capacities, and can affect the water quality of high status catchments if the dynamics of applied P in these soils is not well understood. The aim of this study was to assess dry matter yield, herbage P content, and P use efficiency in six soils deficient in P and ranging in OM content from 8.7% to 76.4% in a pot experiment under increasing P applications using the Mitscherlich equation. Of the six soils investigated, there was a better response in dry matter yield and greater P use efficiency in the soils with greater OM content than the mineral soils. The Mitscherlich model described grass response precisely in organic soils due to the higher plant availability of applied P as a consequence of the poor P sorption capacities of these soils. Despite the higher availability of applied P for plants in organic soils, the P requirements to meet the threshold herbage P content for dietary P supply to ruminants were still very high, which may pose a risk of P loss to the environment if P fertiliser is applied based on recommendations obtained from plant analysis. These results indicate that P fertilisation of organic soils in sensitive catchments poses a potentially high risk of P transfer to water bodies.

Baseline tissue levels of trace metals and metalloids to approach ecological threshold concentrations in aquatic macroinvertebrates

Within the framework of the European Environmental Quality Standards Directive, the biota was recognized as a suitable matrix for monitoring water quality. In the Nalón River basin (North Spain), a catchment subject to historical mining activities, ten macroinvertebrate taxa (4 mayflies, 1 perlid stonefly, 2 caddisflies, 2 oligochaete worms, and 1 blackfly) were collected from unpolluted reference sites in the study area, and the sites were assessed as having High or Good ecological status based on their macroinvertebrate communities to establish a metal bioaccumulation reference condition. For each taxon, tissue concentrations of seven metals (Cd, Cr, Cu, Hg, Ni, Hg, and Zn) and two metalloids (As and Se) were measured and interpreted as natural baseline tissue concentrations that reflected the natural variability of the region. The taxa selected as biomonitors represented 5 different feeding styles in the benthic community: deposit-feeders, scrapers, filterers, generalists and predators, and bioaccumulation was analyzed both by taxon and feeding style as well as general habits (endo- vs epi-benthic) and river type. For each taxon, ecological threshold tissue concentrations (ETTC) were calculated as the 90th percentile (P90) of the baseline data distribution. In most instances, the deposit-feeders (aquatic lumbricid and microdrile oligochaetes) showed the highest ETTCs, except for Cu and Zn, which were mainly bioaccumulated by generalist Ephemerellidae, followed by scraper Heptageniidae in the case of Cu. The P90 values were derived from organisms in unaltered reference conditions as estimates of the no-observed-effect concentrations (NOEC), and should provide an approach to ETTCs for the field macroinvertebrate taxa of the region below which the alteration of the benthic community is unlikely. For each metal and metalloid, the P90s for the 10 taxa were entered in a species-sensitivity-distribution model, and the median hazard concentration (HC50) for the macroinvertebrate community was calculated. The ecological threshold concentrations in the biota calculated in this study are proposed for use as a screening tool in the environmental risk assessment of the Nalón River basin and the Cantabrian region, allowing metal exceedance in the selected biomonitors to further research using other lines of evidence under the European Water Framework directive.

A participatory approach for comparing stakeholders’ evaluation of P loss mitigation options in a high ecological status river catchment

Phosphorus (P) transfer from land to water is a source of diffuse pollution that contributes to the decline in ecological status of river bodies in the European Union. The Water Framework Directive (2000/60/EC) provides for the protection of water bodies that represent pristine or near-pristine condition, classified as high ecological status through the adoption of an agri-environmental decision making process that promotes stakeholder participation. However, successful implementation of agri-environmental policies can prove challenging when faced with uncertainties and diverging opinions due to the variety of actors involved. This study adopted a participatory approach including stakeholders with conflicting interests in the selection of P transfer mitigation policies. Fifteen P transfer mitigation options were shortlisted based on agronomic and environmental data from a case-study agricultural catchment and presented to a group of experts and farmers. Results showed significant disparities between perceived effectiveness by farmers and experts groups, with experts prioritizing problems related to connectivity issues, while farmers to soil compaction and erosion. In addition, measured agronomic and environmental variables were used to model effectiveness from a decision support tool (FARMSCOPER) and compared with stakeholder groups’ perceived effectiveness. This approach combined the scientific research with the empirical knowledge of farmers and the modelling of quantified field and farm data. This study showed that stakeholders are diverse, and perceive effectiveness based on group-specific operational and social factors. Experts identified effectiveness at catchment scale, whilst farmers identified field scale effectiveness. For decision support tools and simulation models to be beneficial for policy makers, they need to be calibrated to local conditions and farm typologies to select the right measure at farm scale. The study recommends improved knowledge transfer between interested actors and the need for integration of conflicting opinions in policy design. A bottom-up approach to decision making is suggested, to assist in the decentralization of the procedures towards more effectively implemented P transfer mitigation policies.

A river vegetation quality metric in the eco‐hydromorphology philosophy

AbstractVegetation is a key biological element used to assess the ecological status of rivers, for example, under the EU Water Framework Directive. Current macrophyte‐based river vegetation metrics may not accurately reflect overall ecological state, particularly when plant community components are weakly related to broader hydromorphological context. A more holistic River Vegetation Quality Metric (RVQM) is proposed. The RVQM applies an eco‐hydromorphic approach to assessment of vegetation integrity, with a focus on lowland (low–moderate energy) rivers. The concepts underlying the RVQM and the methods for applying this new metric are presented and discussed. A pilot study then explores relationships between the RVQM and recorded physical variables in 119 sites (river reaches) within 27 rivers across Ireland. Statistical models suggest that the RVQM score for these study sites was most strongly related to physical components (assessed under the River Hydromorphology Assessment Technique). Water quality (assessed using a benthic invertebrate metric, Q‐value) also had a positive effect on RVQM score, but high ecological status was only recorded in sample sites with natural morphology and hydraulics, irrespective of water quality. Results indicate that interactions between vegetation and hydromorphological descriptors within the river corridor deserve greater consideration when assigning ecological status to lowland rivers.

Zooplankton communities in three adjacent softwater lobelia lakes of slightly differentiated morphology and trophic state

Abstract The paper presents the results of an investigation of physical-chemical features of water as well as rotifer and crustacean abundance and diversity measures, relating to the taxonomic richness and species diversity index, in three lobelia lakes differing in trophic status and morphometric features. The main purpose of this study was to establish the diversity of zooplankton communities in the open water area of lobelia lakes, including extracting species common for each lake and also to find environmental predictors which are responsible for the development of zooplankton communities. Despite the fact that the three studied lakes are of the same origin, located in the same vicinity and have generally similar environmental factors, zooplankton community structure revealed a great variation in reference to species diversity (only ca. 20% of the species were common for all lakes) and particularly in inhabiting species. Obrowo Lake had the most diverse assemblages of both rotifers and crustaceans compared to Modre and Pomysko lakes. In the taxonomic structure species that are rare for the Polish fauna, such as e.g. Holopedium gibberum and Heterocope appendiculata, occurred. Even though the examined lobelia lakes are ecosystems that undergo varying human-induced impacts, they still remain taxonomically very variable aquatic ecosystems, containing rare species of very high ecological status. The observed symptoms of deterioration of water quality, reflected in the zooplankton biocoenotic features, showed that the best conditions were attributed to Obrowo Lake in comparison with the two remaining lakes – Modre and Pomysko. Total nitrogen and chlorophyll a concentration were decisive for the distribution of zooplankton species in Pomysko and Obrowo lakes, while in case of Modre lake water reactivity and conductivity were of higher impact.

A pilot macroinvertebrate-based multimetric index (MMI-CS) for assessing the ecological status of the Chishui River basin, China

As the only undammed river in the Yangtze River basin and an important rare fish reserve, the Chishui River has attracted the world's attention. It was recently selected as a reference river for a pilot biomonitoring assessment within the European Union-China River Basin Management Programme. As the outcome of the project, a pilot multimetric index (MMI-CS) was developed for future assessment of the ecological status of the Chishui River basin. In this study, eight core metrics were selected and used to build the multimetric system. These metrics included the total number of taxa (TotalTax), the number of taxa of sprawlers (SprwlTax), the number of intolerant taxa (IntolTax), the Hilsenhoff biotic index (HBI), the percentage of Ephemeroptera, Trichoptera and Plecoptera (EPTPct), the number of Ephemeroptera taxa (EphemTax), the percentage of collectors (CllctPct) and the average score per taxon (ASPT). Five ecological status ratings (“Excellent”, “Good”, “Fair”, “Poor” and “Very Poor”) were established. The results of the evaluation showed that the index was reasonable and effective. The results of the assessment showed that sites with higher ecological status were distributed mainly in the upper and middle reaches of the region and that sites with lower ecological status were centrally distributed in the lower reaches. Moreover, the index should be refined and validated using additional datasets obtained in different seasons in the future for routine bioassessment within the framework of sustainable management.

Taxa-specific eco-sensitivity in relation to phytoplankton bloom stability and ecologically relevant lake state

Phytoplankton (including plant-like, animal-like algae and Cyanobacteria) blooms have recently become a serious global threat to the sustenance of ecosystems, to human and animal health and to economy. This study focused on the composition and stability of blooms as well as their taxa-specific ecological sensitivity to the main causal factors (especially phosphorus and nitrogen) in degraded urban lakes. The analyzed lakes were assessed with respect to the trophic state as well as ecological status. Total phytoplankton biomass (ranging from 1.5 to 181.3 mg dm−3) was typical of blooms of different intensity, which can appear during a whole growing season but are the most severe in early or late summer. Our results suggested that steady-state and non-steady-state bloom assemblages including mono-, bi- and multi-species or heterogeneous blooms may occur in urban lakes. The most intense blooms were formed by the genera of Cyanobacteria: Microcystis, Limnothrix, Pseudanabaena, Planktothrix, Bacillariophyta: Cyclotella and Dinophyta mainly Ceratium and Peridinium. Considering the sensitivity of phytoplankton assemblages, a new eco-sensitivity factor was proposed (E-SF), based on the concept of Phytoplankton Trophic Index composed of trophic scores of phytoplankton taxa along the eutrophication gradient. The E-SF values of 0.5, 1.3, 6.7 and 15.1 were recognized in lakes having a high, good, moderate or poor ecological status, respectively. For lake restoration, each type of bloom should be considered separately because of different sensitivities of taxa and relationships with environmental variables. Proper recognition of the taxa-specific response to abiotic (especially to N and P enrichment) and biotic factors could have significant implications for further water protection and management.

Assessing the risk of phosphorus transfer to high ecological status rivers: Integration of nutrient management with soil geochemical and hydrological conditions

Agriculture has been implicated in the loss of pristine conditions and ecology at river sites classified as at ‘high ecological status’ across Europe. Although the exact causes remain unclear, diffuse phosphorus (P) transfer warrants consideration because of its wider importance for the ecological quality of rivers. This study assessed the risk of P loss at field scale from farms under contrasting soil conditions within three case-study catchments upstream of near-pristine river sites. Data from 39 farms showed P surpluses were common on extensive farm enterprises despite a lower P requirement and level of intensity. At field scale, data from 520 fields showed that Histic topsoils with elevated organic matter contents had low P reserves due to poor sorption capacities, and received applications of P in excess of recommended rates. On this soil type 67% of fields recorded a field P surplus of between 1 and 31kgha−1, accounting for 46% of fields surveyed across 10 farms in a pressured high status catchment. A P risk assessment combined nutrient management, soil biogeochemical and hydrological data at field scale, across 3 catchments and the relative risks of P transfer were highest when fertilizer quantities that exceeded current recommendations on soils with a high risk of mobilization and high risk of transport as indicated by topographic wetness index values. This situation occurred on 21% of fields surveyed in the least intensively managed catchment with no on-farm nutrient management planning and soil testing. In contrast, the two intensively managed catchments presented a risk of P transfer in only 3% and 1% of fields surveyed across 29 farms. Future agri-environmental measures should be administered at field scale, not farm scale, and based on soil analysis that is inclusive of OM values on a field-by-field basis.

Assessment and Characterisation of Ireland's Green Tides (Ulva Species).

Enrichment of nutrients and metals in seawater associated with anthropogenic activities can threaten aquatic ecosystems. Consequently, nutrient and metal concentrations are parameters used to define water quality. The European Union’s Water Framework Directive (WFD) goes further than a contaminant-based approach and utilises indices to assess the Ecological Status (ES) of transitional water bodies (e.g. estuaries and lagoons). One assessment is based upon the abundance of opportunistic Ulva species, as an indication of eutrophication. The objective of this study was to characterise Ireland’s Ulva blooms through the use of WFD assessment, metal concentrations and taxonomic identity. Furthermore, the study assessed whether the ecological assessment is related to the metal composition in the Ulva. WFD algal bloom assessment revealed that the largest surveyed blooms had an estimated biomass of 2164 metric tonnes (w/w). DNA sequences identified biomass from all locations as Ulva rigida, with the exception of New Quay, which was Ulva rotundata. Some blooms contained significant amounts of As, Cu, Cr, Pb and Sn. The results showed that all metal concentrations had a negative relationship (except Se) with the Ecological Quality Ratio (EQR). However, only in the case of Mn were these differences significant (p = 0.038). Overall, the metal composition and concentrations found in Ulva were site dependent, and not clearly related to the ES. Nevertheless, sites with a moderate or poor ES had a higher variability in the metals levels than in estuaries with a high ES.

External nutrient loading from land, sea and atmosphere to all 656 Swedish coastal water bodies

Identifying the main sources of nutrient loading is a key factor for efficient mitigation of eutrophication. This study has investigated the pathways of external nutrient loading to 656 coastal water bodies along the entire Swedish coastline. The studied water bodies have been delineated to meet requirements in the European Union's Water Framework Directive, and recent status assessments have shown that 57% of them fail to attain good or high ecological status with respect to nutrients. The analysis in the study was performed on data from mass-balance based nutrient budgets computed using the modelling framework Vattenwebb. The external nutrient contribution from the sea to the water bodies was highly variable, ranging from about 1% to nearly 100%, but the median contribution was >99% of the total external loading regarding both nitrogen and phosphorus. External loading from the atmosphere and local catchment area played a minor role in general. However, 45 coastal water bodies received >25% of the external nitrogen and phosphorus from their catchments. Loading from land typically peaked in April following ice-break and snow melting and was comparatively low during summer. The results indicate that for many eutrophicated Swedish coastal water bodies, nutrient abatement is likely to be optimally effective when potential measures in all of the catchment area of the concerned sea basin are considered. Local-scale mitigation in single water bodies will likely be locally effective only in the small proportion of areas where water and thereby also nutrient input from the catchment is high compared to the influx from the sea. Future studies should include nutrient reduction scenarios in order to refine these conclusions and to identify relevant spatial scales for coastal eutrophication mitigation measures from a water body perspective.

Structuring factors of the spatio-temporal variability of macrozoobenthos assemblages in a southern Mediterranean lagoon: How useful for bioindication is a multi-biotic indices approach?

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.

Accumulation of metals relevant for agricultural contamination in gills of European chub (Squalius cephalus).

The study of metal bioaccumulation in the gills of European chub (Squalius cephalus) was conducted in September 2009 at the medium-sized rural river Sutla, characterized by agricultural and municipal type of water contamination. The concentration ranges were established for the first time in the soluble, metabolically available fractions of chub gills for 12 metals, which are environmentally extremely relevant and yet only seldom studied, as follows in a decreasing order: K, 225-895mgL(-1); Na, 78-366mgL(-1); Ca, 19-62mgL(-1); Mg, 13-47mgL(-1); Rb, 164-1762μgL(-1); Sr, 24-81μgL(-1); Ba, 13-67μgL(-1); Mo, 1.3-16μgL(-1); Co, 0.7-2.7μgL(-1); Li, 0.4-2.2μgL(-1); Cs, 0.2-1.9μgL(-1); and V, 0.1-1.8μgL(-1). The concentrations of Fe (1.6-6.4mgL(-1)) and Mn (16-69μgL(-1)) were also determined and were in agreement with previous reports. By application of general linear modelling, the influence of different abiotic (metal exposure level) and biotic parameters (fish sex, age, size and condition) on metal bioaccumulation was tested. It was established that bioaccumulation of many metals in fish depended on various physiological conditions, wherein Ba could be singled out as metal exhibiting the strongest association with one of biotic parameters, being significantly higher in smaller fish. However, it was also undoubtedly demonstrated that the concentrations of three metals can be applied as reliable indicators of metal exposure even in the conditions of low or moderate water contamination, such as observed in the Sutla River, and those were nonessential elements Li and Cs and essential element Fe. The results of our study present an important contribution to maintenance of high ecological status of European freshwaters, through enrichment of knowledge on the bioaccumulation of various metals in gills of European chub as frequently applied bioindicator species in monitoring of water pollution.

Water quality and recreational angling demand in Ireland

Using on-site survey data from sea, coarse and game angling sites in Ireland this paper estimates count data models of recreational angling demand. The models are used to investigate the extent to which anglers are responsive to differences in water quality, with the water quality metric defined by the EU's Water Framework Directive. The analysis shows that angling demand is greater where water quality has a higher ecological status, particularly for anglers targeting game species. However, for coarse anglers we find the reverse, angling demand is greater in waters with lower ecological status. On average across the different target species surveyed anglers have a willingness to pay of € 371 for a day's fishing. The estimated additional benefit of fishing in waters with high versus low ecological status is € 122/day for game anglers but there is a decline in benefit of € 93/day for coarse anglers. Management implicationsWhile one of the objectives of the Water Framework Directive (WFD) is to attain and retain good status in water bodies, the diversity in angler preferences means that not all anglers may be affected similarly by efforts that seek to improve water quality. Achieving good water status closely aligns with the interests of game anglers. However, we find that coarse angling demand is higher at sites with poor or bad ecological status. Therefore, what might be considered an improvement in water quality from a WFD perspective may be considered otherwise by coarse anglers, though, further research is required to rule out coincidental correlation between water quality and site specific characteristics important to coarse anglers.

Estimating the effects of land use at different scales on high ecological status in Irish rivers

High ecological status at river sites is an indicator of minimal disturbance from anthropogenic activities and the presence of ecologically important species and communities. However, a lack of clarity on what factors cause sites to lose high ecological status is limiting the ability to maintain the quality of these sites. Examination of ecological status records at 508 high status river sites throughout the Republic of Ireland revealed that 337 had fallen below high status at some point between 2001 and 2012 due to changes in invertebrate communities. A geographical information system was used to characterise land use and environmental variables in the catchment, riparian and reach areas upstream of the sites. The relationships between these variables at the three spatial scales and whether or not river sites had maintained high ecological status were then estimated by multiple logistic regression and propensity modelling. The results indicated that grassland at either catchment or riparian scales had a greater negative impact on high ecological status than at the reach scale. This effect appeared to be strongest for upland, steeply sloping rivers that are subject to high rainfall, possibly due to the presence of sensitive biota and/or a greater potential for erosion. These results highlighted the need for better management of grassland upstream of the high status sites, with a focus on river alterations and critical source areas of nutrients, sediments and pesticides that are hydrologically connected to the river. Sustainable management practices and land use planning in those areas will need to be considered carefully if the aim of maintaining high ecological status at river sites is to be achieved.