Spatial and temporal variation in the prevalence of illegal lead shot in reared and wild mallards harvested in England.

The use of lead shotgun ammunition for shooting wildfowl has been restricted in England since 1999, but surveys finding lead shot in harvested birds show compliance with regulations has been low. Following the announcement in 2020 of a voluntary transition from lead to non-lead shot by UK shooting organizations, we investigated spatiotemporal variation in the composition of ammunition used for shooting mallards Anas platyrhynchos. We collected 176 harvested mallards during the 2021/22 shooting season and analyzed recent shot extracted from carcasses to determine shot composition. Using a separate collection of ducks of known provenance, we used stable isotope analysis as a means of differentiating captive-reared from wild mallards. This allowed us to understand how compliance might vary between driven game shooters, characterized by shooting birds that are flushed over a stationary line of shooters, and who primarily harvest captive-reared and released ducks, and wild duck shooters. Of 133 mallards containing recent shot, 92 (69%) had been illegally shot with lead. Analysis of this and five comparable surveys between 2001 and 2019 indicates regional and temporal variation in lead shot presence in England. In the North West and West Midlands, the likelihood of mallards containing lead shot decreased significantly over time, but no other regions showed significant changes. The use of non-lead shot types varied over time, with increases in steel shot use approximately matched by declines in bismuth shot. Mallards likely to be reared were more likely to have been shot with lead (75%) than those likely to be wild (48%). This suggests the use of lead shot is more frequent among driven game shooters than wild duck shooters. In England in 2021/22, most mallards continued to be shot with lead, suggesting that neither legislation nor voluntary approaches have been effective in substantially reducing illegal use of lead shot.

Protect wildlife from livestock diseases.

This summer, seabirds in Europe, North America, and Africa suffered unprecedented high mortality as highly pathogenic avian influenza (HPAI) swept through their breeding colonies. Given that the potential for HPAI-which originated in farmed poultry-to affect wild birds has been known for more than a decade, how were these continents caught off guard? Nations must assume responsibility for protecting wildlife from anthropogenic diseases, particularly those originating from ever-increasing livestock populations.

European mammal exposure to lead from ammunition and fishing weight sources.

Ammunition and fishing weight usage is the greatest largely unregulated contributor of lead (Pb) deposition to the European environment. While the range of negative impacts of Pb exposure to humans and avian wildlife are relatively well documented, little is known about risks to wild mammals despite recent scientific interest and publications. A qualitative risk assessment of the potential Source-Pathway-Receptor linkages for European mammal exposure was conducted, based on literature reviews and existing evidence and discussions with experts from the fields of wild mammal feeding ecology, behaviour and health. The assessment identified 11 pathways for mammal exposure to Pb, with all 243 European species likely to be potentially exposed via one or more of these. All species were identified as potentially exposed via ingestion of water with elevated Pb from degraded ammunition/fishing weights. Ingestion of vegetation with elevated Pb from degraded ammunition/fishing weights potentially exposed many species (158), 78% of which had a potentially high risk of exposure when feeding in areas of high Pb deposition. Ingestion of retained ammunition in previously shot prey and/or discarded kill/gut piles with embedded ammunition was another significant pathway, contributing to predatory and scavenging carnivorous mammal exposure where an individual exposure event would be expected to be high. The mechanisms by which Pb from ammunition and fishing weight sources are moved up trophic levels and 'transferred' from areas of high deposition into wider food chains e.g. via water, flying invertebrates and herbivores being subsequently preyed upon requires further investigation. In conclusion, there are multiple and diverse Source-Pathway-Receptors linkages for European mammal exposures to Pb and evidence of exposure, from Europe and elsewhere, exists for some herbivores, carnivores, omnivores and insectivores. Both fatal but more likely non-fatal chronic and acute exposures may be expected to occur in wild European mammalian species, including those in poor conservation status.

Sarcocystis rileyi in UK free-living wildfowl (Anatidae): surveillance, histopathology and first molecular characterisation.

BACKGROUND: Reports from UK hunters of 'rice grains' in muscles of shot wildfowl (Anatidae) coincided temporally with the finding of sarcocystosis in a number of ducks found as part of the Wildfowl & Wetlands Trust long-term general surveillance of found dead waterbirds. Sarcocystis rileyi has also been relatively recently confirmed in wildfowl in north-eastern Europe. METHODS: This study uses four approaches to investigate UK wildfowl sarcocystosis: first, through a hunter questionnaire that captured historical case data; secondly, through an online reporting system; thirdly, DNA sequencing to characterise UK cases; and fourthly, histological myopathy assessment of infected pectoral muscle. RESULTS: Our questionnaire results suggest Sarcocystis infection is widely distributed throughout the UK and observed in 10 Anatidae species, reported cases increased since the 2010/2011 shooting season, with the online reporting system reflecting this increase. DNA sequencing (18S rRNA gene and internal transcribed spacer-1 region) of UK isolates confirmed S rileyi in the five dabbling duck host species tested and the associated histopathological myopathy is described. CONCLUSION: This work highlights an emerging issue to European wildfowl species and provides much opportunity for further research, including the impacts of S rileyi and the described myopathy on host health, fitness and survival.

Wetlands for Wellbeing: Piloting a Nature-Based Health Intervention for the Management of Anxiety and Depression.

Nature-based health interventions (NBIs) for the treatment of poor mental health are becoming increasingly common, yet evidence to support their effectiveness is lacking. We conduct a pilot study of a six-week intervention, aiming to engage individuals with wetland nature for the treatment of anxiety and/or depression. We employed a mixed methods design, using questionnaires, focus groups and semi-structured interviews to evaluate the intervention from the perspective of participants (n = 16) and healthcare professionals (n = 2). Results demonstrate significant improvements in mental health across a range of indicators, including mental wellbeing (Warwick and Edinburgh Mental Wellbeing Scale), anxiety (Generalised Anxiety Disorder-7), stress (Perceived Stress Scale) and emotional wellbeing (Positive and Negative Affect Schedule). Participants and healthcare professionals cited additional outcomes including improved physical health and reduced social isolation. The wetland site provided a sense of escape from participants' everyday environments, facilitating relaxation and reductions in stress. Wetland staff knowledge of the natural world, transportation and group organisation also played a considerable role in the intervention's success. These aspects should be considered in future and existing NBIs to maximise benefits to participants. We propose NBIs based in wetlands are an effective therapy option for individuals diagnosed with anxiety and/or depression.

The Application of Wearable Technology to Quantify Health and Wellbeing Co-benefits From Urban Wetlands.

Improved nature provision in urban environments offers great potential for achieving both biodiversity conservation and public health objectives. Yet there are few experimental studies that address links between specific natural environments and physiological and/or psychological changes that could contribute to the health and wellbeing co-benefits of urban nature. In addition, relative to green space, the salutogenic impact of aquatic environments are understudied. Here, we present a feasibility study examining the use of low-cost wearable technology to quantify the psychophysiological effects of short-term exposure to urban wetlands. The study took place at the WWT London Wetland Centre, which is characterized by its contrasting biodiverse wetland habitat and surrounding urban setting. Thirty-six healthy participants experienced counterbalanced exposures to an indoor space, a wetland, an urban site. We continuously recorded electroencephalographic (EEG) data and real-time physiological stress responses; with additional monitoring of post-exposure self-reported mood states. We found a significant effect of site on mean resting heart rate (HR), with increased HR in the urban setting, although this was only observed in participants with pre-existing high stress. We found no significant differences in other measures of physiological stress responses (heart rate variability and electrodermal activity). The EEG data showed modulation of high beta band activity only in the wetland setting, potentially related to changes in attention. However, the EEG findings were confounded by low quality signals and artifacts caused by movement and environmental interference. Assessments of self-reported mood states demonstrated an increase in positive feelings in the wetland setting. A pronounced decrease in negative feelings in the wetland setting was observed in stressed individuals only. Our results suggest that pre-existing stress levels may be an important modulator of the salutogenic effect of blue-green space. We provide partial support for the hypothesis that exposure to blue-green space promotes stress recovery and for the use of low-cost psychophysiological measurements to quantify the potential stress-reducing effects of blue-green space exposure in urban dwellers. Further technological refinement is required for this approach to become a viable tool to support evidence-based decision-making for public health and green/blue space provision.

Transitioning to non-toxic ammunition: Making change happen.

If the multiple negative health impacts associated with lead ammunition are to be mitigated, a transition to the non-toxic alternatives is needed. This paper aims to map out the pathways to such a transition via a modification of Kotter's eight step theory of change, identifying key stakeholders, exploring options for those of us advocating change and the relationships between policy and persuasion. The focus is primarily on the UK, but it is of direct relevance to the rest of Europe and beyond. The theory of change model involves (1) creating urgency, (2) building coalitions, (3) creating a vision for change, (4) communicating that vision, (5) removing barriers to enable action, (6) creating short-term or geospatial wins, (7) building on the change and (8) embedding change in culture and regulation. The paper reflects on good progress to date in initial steps, but throughout subsequent steps creative engagement and other disciplines which appreciate the human dimensions such as mediation and psychology of behaviour change have been lacking. Although significant barriers remain for Step 5, the paper identifies the central vision of sustainability of hunting as a shared value around which most stakeholders can engage. The paper concludes that, given the growing momentum surrounding this issue in recent years, the phasing out of lead ammunition is at a tipping point.

Wildlife, human and environmental costs of using lead ammunition: An economic review and analysis.

A proposed European Union (EU)-wide restriction on the use of lead gunshot for shooting in and over wetlands estimated that the societal benefits of a restriction outweighed costs, despite few identified benefits being quantified economically. A subsequent Annex XV Investigation Report on the evidence of impacts of lead ammunition in terrestrial environments concluded that additional measures to control its use are warranted, although to date this has not been further evaluated. To help inform this process, we review the literature and undertake new analyses to estimate the costs of continued use of lead ammunition associated with impacts on wildlife, people and the environment. We estimate minimum annual direct costs across the EU and Europe of c. €383 million-€960 million and €444 million-€1.3 thousand million respectively. The value that society places on being able to avoid these losses, estimated using a 'willingness to pay' approach, was c. €2.2 thousand million for wildfowl alone. Our estimated costs of the continued use of lead ammunition across the EU appear to be considerably greater than the likely costs of switching to non-toxic alternative ammunition types, although these have not been formally estimated in full.

The Evolution of Innate Immune Genes: Purifying and Balancing Selection on ß-Defensins in Waterfowl.

In disease dynamics, high immune gene diversity can confer a selective advantage to hosts in the face of a rapidly evolving and diverse pathogen fauna. This is supported empirically for genes involved in pathogen recognition and signalling. In contrast, effector genes involved in pathogen clearance may be more constrained. ß-Defensins are innate immune effector genes; their main mode of action is via disruption of microbial membranes. Here, five ß-defensin genes were characterized in mallards (Anas platyrhynchos) and other waterfowl; key reservoir species for many zoonotic diseases. All five genes showed remarkably low diversity at the individual-, population-, and species-level. Furthermore, there was widespread sharing of identical alleles across species divides. Thus, specific ß-defensin alleles were maintained not only spatially but also over long temporal scales, with many amino acid residues being fixed across all species investigated. Purifying selection to maintain individual, highly efficacious alleles was the primary evolutionary driver of these genes in waterfowl. However, we also found evidence for balancing selection acting on the most recently duplicated ß-defensin gene (AvBD3b). For this gene, we found that amino acid replacements were more likely to be radical changes, suggesting that duplication of ß-defensin genes allows exploration of wider functional space. Structural conservation to maintain function appears to be crucial for avian ß-defensin effector molecules, resulting in low tolerance for new allelic variants. This contrasts with other types of innate immune genes, such as receptor and signalling molecules, where balancing selection to maintain allelic diversity has been shown to be a strong evolutionary force.

ASSESSMENT OF THE RATES OF INJURY AND MORTALITY IN WATERFOWL CAPTURED WITH FIVE METHODS OF CAPTURE AND TECHNIQUES FOR MINIMIZING RISKS.

Swan pipes, duck decoys, cage traps, cannon netting, and roundups are widely used to capture waterfowl in order to monitor populations. These methods are often regulated in countries with national ringing or banding programs and are considered to be safe, and thus justifiable given the benefits to conservation. However, few published studies have addressed how frequently injuries and mortalities occur, or the nature of any injuries. In the present study, rates of mortality and injury during captures with the use of these methods carried out by the Wildfowl & Wetlands Trust as part of conservation programs were assessed. The total rate of injury (including mild dermal abrasions) was 0.42% across all species groups, whereas total mortality was 0.1% across all capture methods. Incidence of injury varied among species groups (ducks, geese, swans, and rails), with some, for example, dabbling ducks, at greater risk than others. We also describe techniques used before, during, and after a capture to reduce stress and injury in captured waterfowl. Projects using these or other capture methods should monitor and publish their performance to allow sharing of experience and to reduce risks further.

Potential hazard to human health from exposure to fragments of lead bullets and shot in the tissues of game animals.

BACKGROUND: Lead is highly toxic to animals. Humans eating game killed using lead ammunition generally avoid swallowing shot or bullets and dietary lead exposure from this source has been considered low. Recent evidence illustrates that lead bullets fragment on impact, leaving small lead particles widely distributed in game tissues. Our paper asks whether lead gunshot pellets also fragment upon impact, and whether lead derived from spent gunshot and bullets in the tissues of game animals could pose a threat to human health. METHODOLOGY/PRINCIPAL FINDINGS: Wild-shot gamebirds (6 species) obtained in the UK were X-rayed to determine the number of shot and shot fragments present, and cooked using typical methods. Shot were then removed to simulate realistic practice before consumption, and lead concentrations determined. Data from the Veterinary Medicines Directorate Statutory Surveillance Programme documenting lead levels in raw tissues of wild gamebirds and deer, without shot being removed, are also presented. Gamebirds containing > or =5 shot had high tissue lead concentrations, but some with fewer or no shot also had high lead concentrations, confirming X-ray results indicating that small lead fragments remain in the flesh of birds even when the shot exits the body. A high proportion of samples from both surveys had lead concentrations exceeding the European Union Maximum Level of 100 ppb w.w. (0.1 mg kg(-1) w.w.) for meat from bovine animals, sheep, pigs and poultry (no level is set for game meat), some by several orders of magnitude. High, but feasible, levels of consumption of some species could result in the current FAO/WHO Provisional Weekly Tolerable Intake of lead being exceeded. CONCLUSIONS/SIGNIFICANCE: The potential health hazard from lead ingested in the meat of game animals may be larger than previous risk assessments indicated, especially for vulnerable groups, such as children, and those consuming large amounts of game.

PCR analysis of the presence and location of Mycobacterium avium in a constructed reed bed, with implications for avian tuberculosis control.

The potential of reed beds to act as biofilters of pathogenic and environmental mycobacteria was investigated through examination of the fate of mycobacteria in a constructed reed bed filtering effluent from a large captive wildfowl collection. Particular emphasis was placed on the presence and location of Mycobacterium avium--the causal agent of avian tuberculosis (ATB)--in an effort to clarify the potential role of reed beds in the control of this disease. Water, sediment, and stems and roots of common reed (Phragmites australis) and greater reedmace (Typha latifolia) were taken from 15 locations within the reed bed plus sites upstream and downstream. Samples were analysed for mycobacteria using PCR and specifically for M. avium using nested PCR. Environmental mycobacteria were found throughout the entire reed bed but M. avium was not found downstream of the first vegetation growth. The reed bed was found to effectively remove M. avium from the water through a combination of sedimentation and adsorption onto vegetation stems. The results of this study show that constructed reed beds composed of a settlement lagoon and one or more vegetation beds can act as valuable and ecologically friendly tools in the environmental control of ATB.