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While many studies have considered the ability of eDNA to assess animal communities in lacustrine settings, fewer have considered riverine systems, particularly those spanning the environmental gradients present in large river basins. Such dynamic systems are challenging for eDNA biomonitoring due to differing eDNA transport distances in rivers and the effects of river chemistry. To address this challenge, we focused on the Thames River system, UK, which has exceptional historical fish records providing a baseline to test the accuracy of eDNA metabarcoding in recovering fish community structure across both fresh and tidal zones. Two primer sets targeting 12S and CO1 regions were used to capture fish communities across the Thames catchment, from the upper freshwaters to the mid estuary. eDNA was collected at 35 sites, 14 of which were simultaneously paired with traditional fish surveys for direct comparison. We demonstrated that eDNA metabarcoding consistently detected more freshwater species than traditional methods, despite extensive sampling effort using the latter. In contrast, metabarcoding did not perform as well as traditional approaches in estuarine waters, although results included the novel detection of the protected sea lamprey. We further demonstrated that minor variations in the recovery of all approaches would not impact on the assessment of simple ecological models of community structure and, thus, some variability between approaches should not be viewed as a serious hindrance to uptake. Rather, our findings support a growing consensus that eDNA can reliably detect fish communities across dynamic freshwater habitats.

Monitoring the condition (water quality, biodiversity, hydromorphology) of small water bodies presents a challenge for the relevant authorities in terms of time and resources (labour and financial) due to the extensive length of the stream network or the sheer number of small standing water bodies. Citizen science can help address information gaps, but the effort required should not be underestimated if such projects are to generate reliable and sustained data collection. The overall aim of this paper is to propose a framework for operationalisation of citizen science targeting collection of data from small water bodies. We first consider the data gaps and the elements (water chemistry, ecology, hydromorphology) to be addressed, in order to define where citizen science could best make an impact. We review examples of tools and methods that are appropriate for small water bodies, based on experience from a selection of freshwater citizen science projects, and the support that is needed for effective and sustained small water body projects across Europe.

Leading organisations recommend follow-up of acute kidney injury (AKI) survivors, as these patients are at risk of long-term complications and increased mortality. Information transfer between specialties and from tertiary to primary care is essential to ensure timely and appropriate follow-up. Our aim was to examine the association between completeness of discharge documentation and subsequent follow-up of AKI survivors who received kidney replacement therapy (KRT) in the Intensive Care Unit (ICU). We retrospectively analysed the data of 433 patients who had KRT for AKI during ICU admission in a tertiary care centre in the UK between June 2017 and May 2018 and identified patients who were discharged from hospital alive. Patients with pre-existing end-stage kidney disease and patients who were transferred from hospitals outside the catchment area were excluded. The primary objective was to assess the completeness of discharge documentation from critical care and hospital; secondary objectives were to determine cardiovascular medications reconciliation after AKI, and to investigate kidney care and outcomes at 1 year. The development of AKI and the need for KRT were mentioned in 85 and 82% of critical care discharge letters, respectively. Monitoring of kidney function post-discharge was recommended in 51.6% of critical care and 36.3% of hospital discharge summaries. Among 35 patients who were prescribed renin-angiotensin-aldosterone system inhibitors before hospitalisation, 15 (42.9%) were not re-started before discharge from hospital. At 3 months, creatinine and urine protein were measured in 88.2 and 11.8% of survivors, respectively. The prevalence of chronic kidney disease stage III or worse increased from 27.2% pre-hospitalisation to 54.9% at 1 year (p < 0.001). Our data demonstrate that discharge summaries of patients with AKI who received KRT lacked essential information. Furthermore, even in patients with appropriate documentation, renal follow-up was poor suggesting the need for more education and streamlined care pathways.

Biological invasions represent a complex phenomenon driven by multiple factors. In this study, a real-time invasion process between a native (Pontastacus leptodactylus) and an invasive (Faxonius limosus) crayfish species was investigated in the Lower Danube (South-East Europe) through an interdisciplinary approach, by measuring various ecological, genetic, physiological and biometric endpoints. The results revealed that the prolonged competition in old invaded sites of the river (at least a decade) either drove the native species to extinction, or, unexpectedly, allowed its survival as highly fragmented populations. However, for the latter situation, several biological and ecological traits differed in the remnant populations: increased trophic position and elemental imbalance for two major macronutrients (C:N molar ratio), low growth, as strongly contracted trophic niche widths and low overlap degree with the invasive crayfish. The data suggest that the prolonged competition induced potential resource partitioning between species, potentially driving their coexistence, as the development of larger and heavier claws within the native males’ population. On the contrary, in more recently invaded sectors of the Lower Danube (3 years), the trophic niche of the native species was significantly larger compared to old invaded sites and characterised by high level of niche overlap, indicating almost identical diet with the invasive crayfish, but characterised by the lowest trophic position compared to other invasion sectors. The genetic diversity of the native crayfish populations was strongly reduced in the invaded sectors of the river, but without signs of genetic bottleneck, which may be explained by a drift-mutational equilibrium reached as a consequence of diminishing population size. Our findings suggest strong coexistence potential in the future for both species in the Lower Danube.

Despite growing interest in the environmental impact of microplastics, a standardized characterization method is not available. We carried out a systematic analysis of reliable global data detailing the relative abundance of polymers in freshwaters and estuaries. The polymers were identified according to seven main categories: polyethylene terephthalate, polyethylene, polyvinyl chloride, polypropylene, polystyrene, polyurethane and a final category of miscellaneous plastic. The results show that microplastics comprised of polyvinyl chloride and polyurethane are significantly less abundant than would be expected based on global production, possibly due to their use. This has implications for models of microplastic release into the environment based on production and fate. When analysed by matrix (water, sediment or biota) distinct profiles were obtained for each category. Polyethylene, polypropylene and polystyrene were more abundant in sediment than in biota, while miscellaneous plastics was more frequent in biota. The data suggest that environmental sorting of microplastic particles, influenced by physical, chemical and biological processes, may play a key role in environmental impact, although partitioning among matrices based on density was not realized. The distinct profile of microplastics in biota raises an important question regarding potential selectivity in uptake by organisms, highlighting the priority for more and better-informed laboratory exposure studies.

We used the systematic review procedure to assess the evidence available on the analysis, prevalence and impact of microplastics in freshwater and estuarine environments. As the study of microplastics in freshwaters is relatively new, measurement methods are yet to be standardized, and a wide variety of methods of variable robustness have been used. Critically, the sampling methodology used in the literature had a systematic influence on the concentration of microplastic particles returned. The volume of water sampled varied over many orders of magnitude, and there was a direct relationship between the size of the smallest particles studied and the volume of water sampled in both freshwater and estuaries: large volumes of water can only be sampled using nets of relatively coarse mesh, which in turn do not capture smaller particles. Consequently, the mean abundance of microplastic particles reported was inversely correlated with both the volume of water sampled and the size of particles studied.The size of microplastic particles had a substantial and overriding effect on threshold concentrations above which microplastics affect freshwater and estuarine biota. For the ecotoxicological endpoints of feeding, behaviour, growth and survival there was a clear relationship between the size of the particles used in the test and the threshold concentration at which an effect was seen. Although the taxonomic coverage of test organisms was limited, there were sufficient data to test the influence of taxonomic group used on size-specific thresholds for Crustacea, fish and algae. There was no significant effect of either the endpoint measured or the taxonomic group used, suggesting that there might not be any difference in sensitivity among different taxa.In order to establish a threshold concentration where microplastics present a hazard to a limited number of taxa, quantile regression was used to determine the size-specific concentration of microplastics that was lower than 90% of the thresholds identified for survival and, as a more conservative limit, across all endpoints tested including sublethal effects. By comparing these thresholds with the data on concentrations of microplastics reported by field studies, it was apparent that the calculated size specific threshold concentration for lethal effects was considerably higher than 99% of reported environmental concentrations. Lethal effects of microplastics on freshwater and estuarine biota are likely to be limited to exceptional circumstances. Over certain size ranges the calculated size specific threshold concentration for sublethal effects was exceeded by the highest 10% of concentrations reported from environmental samples, suggesting that there is a risk of sublethal effects in a small proportion of sites.

To develop and validate an improved risk model to predict acute hospital mortality for admissions to adult critical care units in the UK.155,239 admissions to 232 adult critical care units in England, Wales and Northern Ireland between January and December 2012 were used to develop a risk model from a set of 38 candidate predictors. The model was validated using 90,017 admissions between January and September 2013.The final model incorporated 15 physiological predictors (modelled with continuous nonlinear models), age, dependency prior to hospital admission, chronic liver disease, metastatic disease, haematological malignancy, CPR prior to admission, location prior to admission/urgency of admission, primary reason for admission and interaction terms. The model was well calibrated and outperformed the current ICNARC model on measures of discrimination (area under the receiver operating characteristic curve 0.885 versus 0.869) and model fit (Brier's score 0.108 versus 0.115). On average, the new model reclassified patients into more appropriate risk categories (net reclassification improvement 19.9; P0.0001). The model performed well across patient subgroups and in specialist critical care units.The risk model developed in this study showed excellent discrimination and calibration and when validated on a different period of time and across different types of critical care unit. This in turn allows improved accuracy of comparisons between UK critical care providers.

Diffuse water pollution from agriculture (DWPA) is a major environmental concern, with significant adverse impacts on both human and ecosystem health. However, without an appropriate understanding of the multiple factors impacting on water, mitigation measures cannot be targeted. Therefore, this paper addresses this gap in understanding, reporting the hydrochemical monitoring evidence collected from the UK Government's Demonstration Test Catchments (DTC) programme including contrasting chalk and clay/mudstone catchments. We use data collected at daily and sub-daily frequency over multiple sites to address: (1) How does the behaviour of the full range of nitrogen (N) species and phosphorus (P) fractions vary? (2) How do N species and P fractions vary inter- and intra-annually? (3) What do these data indicate about the primary pollution sources? And (4) which diffuse pollution mitigation measures are appropriate in our study landscapes?Key differences in the rates of flux of nutrients were identified, dependent on catchment characteristics. Full N speciation and P fractionation, together with dissolved organic carbon (DOC) enabled identification of the most likely contributing sources in each catchment. Nitrate (NO3-N) was the dominant N fraction in the chalk whereas organic and particulate N comprised the majority of the load in the clay/mudstone catchments. Despite current legislation, orthophosphate (PO4-P) was not found to be the dominant form of P in any of the catchments monitored. The chalk sub-catchments had the largest proportion of inorganic/dissolved organic P (DOP), accompanied by episodic delivery of particulate P (PP). Contrastingly, the clay/mudstone sub-catchments loads were dominated by PP and DOP. Thus, our results show that by monitoring both the inorganic and organic fractions a more complete picture of catchment nutrient fluxes can be determined, and sources of pollution pin-pointed. Ultimately, policy and management to bring nutrient impacts under control will only be successful if a multi-stressor approach is adopted.

Purpose The purpose was to describe clinical pharmacist interventions across a range of critical care units (CCUs) throughout the United Kingdom, to identify CCU medication error rate and prescription optimization, and to identify the type and impact of each intervention in the prevention of harm and improvement of patient therapy. Materials and methods A prospective observational study was undertaken in 21 UK CCUs from November 5 to 18, 2012. A data collection web portal was designed where the specialist critical care pharmacist reported all interventions at their site. Each intervention was classified as medication error, optimization, or consult. In addition, a clinical impact scale was used to code the interventions. Interventions were scored as low impact, moderate impact, high impact, and life saving. The final coding was moderated by blinded independent multidisciplinary trialists. Results A total of 20 517 prescriptions were reviewed with 3294 interventions recorded during the weekdays. This resulted in an overall intervention rate of 16.1%: 6.8% were classified as medication errors, 8.3% optimizations, and 1.0% consults. The interventions were classified as low impact (34.0%), moderate impact (46.7%), and high impact (19.3%); and 1 case was life saving. Almost three quarters of interventions were to optimize the effectiveness of and improve safety of pharmacotherapy. Conclusions This observational study demonstrated that both medication error resolution and pharmacist-led optimization rates were substantial. Almost 1 in 6 prescriptions required an intervention from the clinical pharmacist. The error rate was slightly lower than an earlier UK prescribing error study (EQUIP). Two thirds of the interventions were of moderate to high impact.

International audience; Perennial rivers and streams make a disproportionate contribution to global carbon (C) cycling. However, the contribution of intermittent rivers and ephemeral streams (IRES), which sometimes cease to flow and can dry completely, is largely ignored although they represent over half the global river network. Substantial amounts of terrestrial plant litter (TPL) accumulate in dry riverbeds and, upon rewetting, this material can undergo rapid microbial processing. We present the results of a global research collaboration that collected and analysed TPL from 212 dry riverbeds across major environmental gradients and climate zones. We assessed litter decomposability by quantifying the litter carbon-to-nitrogen ratio and oxygen (O2) consumption in standardized assays and estimated the potential short-term CO2 emissions during rewetting events. Aridity, cover of riparian vegetation, channel width and dry-phase duration explained most variability in the quantity and decomposability of plant litter in IRES. Our estimates indicate that a single pulse of CO2 emission upon litter rewetting contributes up to 10% of the daily CO2 emission from perennial rivers and stream, particularly in temperate climates. This indicates that the contributions of IRES should be included in global C-cycling assessments.

Metal-rich sediments have the potential to impair life in freshwater streams and rivers and, thereby, to inhibit recovery of ecological conditions after any remediation of mine water discharges. Sediments remain metal-rich over long time periods and have long-term potential ecotoxicological interactions with local biota, unless the sediments themselves are physically removed or replaced by less metal-rich sediment. Laboratory-derived environmental quality standards are difficult to apply to the field situation, as many complicating factors exist in the real world. Therefore, there is a strong case to consider other, field-relevant, measures of toxic effects as alternatives to laboratory-derived standards and to seek better biological tools to detect, diagnose and ideally predict community-level ecotoxicological impairment. Hence, this review concentrated on field measures of toxic effects of metal-rich sediment in freshwater streams, with less emphasis on laboratory-based toxicity testing approaches. To this end, this review provides an overview of the impact of metal-rich sediments on freshwater stream life, focusing on biological impacts linked to metal contamination.

Excessive inputs of fine‐grained sediment can damage aquatic ecosystems both by degrading habitat condition and by directly impairing biota. Recent research has improved our understanding of how benthic macroinvertebrates respond to fine‐grained sediment stress, leading to the development of a variety of bioassessment indices based on changes in taxonomic composition and biological trait composition. Use of biological traits as indicators of stress has been advocated on the basis of a better mechanistic understanding of the biotic and abiotic factors acting on benthic communities. We quantified changes in the macroinvertebrate biological trait assemblage from a large number of river reaches spanning a national‐scale gradient of increasing agricultural fine sediment delivery and retention, having first factored out variation associated with the natural environmental gradient, with the aim of robustly testing predictions of trait response. We found strong support for 2 of 18 predictions of how macroinvertebrate traits would respond to fine sediment stress. Furthermore, using an independent dataset, we were able to confirm the response of 5 of 6 trait classes that partial RLQ‐fourth corner analysis found to be significantly associated with the fine sediment gradient. Prevalence of eggs as a resistant form, in combination with either an adult aquatic life stage or crawling, provided the best indication of fine sediment conditions in streams, approaching the performance of taxonomic composition‐based sediment indices, CoFSIsp and EPSImtl. This study has robustly confirmed the potential of macroinvertebrate biological traits as indicators of fine sediment impacts. 1 INTRODUCTION

Mitigation of diffuse water pollution from agriculture is a key national environmental policy objective in England. With the recent introduction of the new agri-environment scheme, Countryside Stewardship, there is an increased emphasis on the macro-spatial targeting of on-farm mitigation measures to reduce pollutant pressures, and a concomitant need to forecast the technically feasible impacts of on-farm measures detailed in current policy and their associated costs and benefits. This paper reports the results of a modelling application to test these limits in the context of the associated costs and benefits for the reduction of diffuse water pollution from agriculture for each Water Framework Directive (WFD) water management catchment (WMC) and nationally. Four mitigation scenarios were modelled, including pollutant source control measures only (SC), mobilisation control measures only (MC), delivery control measures only (DC) and measures for source, mobilisation and delivery control (SMDC) combined. Projected impacts on nitrate, phosphorus and sediment export to water, ammonia, methane and nitrous oxide emissions to the atmosphere, together with the associated costs to the agricultural sector were estimated for each WFD WMC and nationally. Median WMC-scale reductions (with uncertainty ranges represented by 5th–95th percentiles) in current agricultural emissions, were predicted to be highest for the SMDC scenario; nitrate (18%, 11–23%), phosphorus (28%, 22–37%), sediment (25%, 18–43%), ammonia (26%, 17–32%), methane (13%, 7–18%) and nitrous oxide (18%, 16–20%). The median benefit-to-cost ratios (with uncertainty ranges represented by 5th–95th percentiles) were predicted to be in the following order; DC (0.15, 0.09–0.65), MC (0.19, 0.09–0.95), SMDC (0.31, 0.20–1.39) and SC (0.44, 0.19–2.48). Of the four scenarios simulated, the SC and SMDC suites of measures have the greatest potential to deliver reductions in BAU emissions from agriculture, and the best benefit:cost ratio.

It has been suggested that submerged aquatic plants can influence the nutritional quality of the periphyton which grows on their surfaces, making it more nutritious for grazing invertebrates, particularly snails. In return, these grazers might preferentially feed on the periphyton and clear the plants of a potential competitor, with the plants and grazers both gaining from this mutualistic relationship. A highly replicated experiment was conducted, in which the nature of the plant (isoetid and elodeid types compared with similar-shaped inert substrata), the nutrient loading, and the influence of periphyton grazers (the bladder snail, Physa fontinalis) of similar size and history were controlled. Plant growth and survival significantly increased in the presence of the periphyton grazer. Whilst the presence of the grazers had the largest influence on periphyton abundance, nutrient availability and plant type also had effects. Plant type had little influence on the nutritional quality of the periphyton measured as carbohydrate, protein and C:N. Effects of treatment on snail growth, and the timing and extent of snail reproduction disappeared when they were compared with the quantity of periphyton available. There was no evidence of enhanced grazer success in the presence of the live plants compared with inert substrata. Although submerged plants affect the growth and reproduction of the grazers which feed on their surfaces, through differences in the amount of periphyton which grows there, we found no evidence that they manipulate the periphyton to encourage such grazers.

The biodegradation of organic matter ingressing spawning gravels in rivers exerts an oxygen demand which is believed to contribute to detrimental impacts on aquatic ecology including salmonids. Catchment management strategies therefore require reliable information on the key sources of sediment-bound organic matter. Accordingly, a novel source fingerprinting procedure based on analyses of bulk stable 13C and 15N isotope values and organic molecular structures detected using near infrared reflectance (NIR) spectroscopy was tested for assessing the primary sources of sediment-bound organic matter infiltrating artificial Atlantic salmon spawning redds in five rivers across England and Wales. Statistically-verified source fingerprints were identified using a combination of the Kruskal–Wallis H-test, principal component analysis and GA-driven discriminant function analysis. Interstitial sediment samples were obtained from artificial redds using retrievable basket traps inserted at the start of the salmonid spawning season and extracted subsequently in conjunction with critical juvenile phases (eyeing, hatch, emergence, late spawning) of fish development associated with incubation and emergence. Over the duration of these four basket extractions, the overall relative frequency-weighted average median source contributions to the interstitial sediment-bound organic matter sampled in the study rivers ranged between 26% (full uncertainty range 0–100%) and 44% (full uncertainty range 0–100%) for farm yard manures/slurries, 11% (full uncertainty range 0–75%) and 48% (full uncertainty range 0–99%) for damaged road verges, 16% (full uncertainty range (0–78%) and 52% (full uncertainty range (0–100%) for decaying instream vegetation and 4% (full uncertainty range 0–31%) and 10% (full uncertainty range (0–44%) for human septic waste. The results of mass conservation tests suggest that the procedure combining bulk 13C and 15N isotope values and NIR spectroscopy data on organic molecular structures is sensitive to the risks of significant non-conservative tracer behaviour in the fluvial environment and will therefore not necessarily work at all in-channel sites in all catchments.