Inorganic elements in the livers of Eurasian otters, Lutra lutra, from England and Wales in 2007 & 2008: a Predatory Bird Monitoring Scheme (PBMS) report

This is a report on the initial findings of a collaborative study between the Predatory Bird Monitoring Scheme (PBMS) and the Cardiff University Otter Project (CUOP). The study analysed the concentrations of 16 metals and semi-metals in the livers of 107 Eurasian otters (Lutra lutra) that had been found dead in 2007 and 2008 and collected by the CUOP. This aim of this work was to determine the current concentrations of inorganic elements accumulated by otters and whether exposure to heavy metals (lead, mercury, cadmium) in particular is likely to be associated with adverse effects. This is the first study of inorganic elements in otter livers from Europe for nearly 10 years. The otters that were analysed were from England and Wales and included adult and subadult males and females. Liver tissue was analysed using Inductively Coupled Plasma mass spectrometry (ICP-MS) techniques. The concentrations of inorganic elements measured in the present study were within the range previously reported for Eurasian otters in Britain and elsewhere in Europe. Concentrations varied with age and/or sex for some elements. For the heavy metals mercury and cadmium, liver concentrations generally increased with age whereas for lead, juveniles generally had higher liver lead concentrations than adults although for lead these difference were not statistically significant. Aluminium and chromium were the only elements that varied significantly in concentrations between years. It is unclear whether the inter-year variation in aluminium and chromium represent significant inter-year changes in exposure and/or accumulation or may simply reflect local-scale variation in the provenance of otters and their associated exposure. The liver concentrations of heavy metals (mercury, cadmium and lead) in all the otters analysed were below those associated with toxic effects in mammals, although liver lead concentrations in a small number of otters were close to the level of concern

Lead (Pb) concentrations in predatory bird livers 2010 and 2011: a Predatory Bird Monitoring Scheme (PBMS) report

The Predatory Bird Monitoring Scheme (PBMS; http://pbms.ceh.ac.uk/) is the umbrella project that encompasses the Centre for Ecology & Hydrology’s National Capability contaminant monitoring and surveillance work on avian predators. By monitoring sentinel vertebrate species, the PBMS aims to detect and quantify current and emerging chemical threats to the environment and in particular to vertebrate wildlife. Lead (Pb) is a highly toxic metal that acts as a non-specific poison affecting all body systems and has no known biological requirement. Sources of Pb in the environment include lead mining, the refining and smelting of lead and other metals, the manufacture and use of alkyl lead fuel additives, and the use of lead ammunition. The present study is the first two years of a PBMS monitoring programme to quantify the scale of exposure to [and associated risk from] Pb in predatory birds. The aim is to quantify the extent of exposure to lead [as assessed from liver residues] in two predatory bird species, the red kite (Mivus milvus) and the sparrowhawk (Accipiter nisus). The red kite is a scavenger and, as such, is particularly at risk from consumption of Pb ammunition in unretrieved game. Sparrowhawks prey predominantly upon live passerine birds that are unlikely to be shot in the UK; likely sources of exposure are diffuse Pb contamination although some individuals may also be exposed to Pb particles ingested by their prey. We also examined the liver Pb isotope ratios in to explore whether they can be used to ascribe likely sources of any Pb detected in the birds. Red kites had significantly higher Pb concentration than those measured in sparrowhawks but the majority of sparrowhawks and all the red kites had liver Pb concentrations below those thought to cause clinical and sub-clinical adverse effects in Falconiforme species. There was overlap in the liver Pb isotope ratios of red kites and sparrowhawks yet there was evidence of separation between the two species. There was also evidence of overlap with the isotope signature for coal and for Pb shot but the isotope signatures in the bird livers were distinct from that of petrol Pb. The Pb isotope pattern observed in the red kites and sparrowhawks in the current study may reflect the fact that liver Pb concentrations were low in the small sample of birds that were analysed and may have been a result of exposure to low-level, diffuse contamination.birds. Red kites had significantly higher Pb concentration than those measured in sparrowhawks but the majority of sparrowhawks and all the red kites had liver Pb concentrations below those thought to cause clinical and sub-clinical adverse effects in Falconiforme species. There was overlap in the liver Pb isotope ratios of red kites and sparrowhawks yet there was evidence of separation between the two species. There was also evidence of overlap with the isotope signature for coal and for Pb shot but the isotope signatures in the bird livers were distinct from that of petrol Pb. The Pb isotope pattern observed in the red kites and sparrowhawks in the current study may reflect the fact that liver Pb concentrations were low in the small sample of birds that were analysed and may have been a result of exposure to low-level, diffuse contamination

Persistent Organic Pollutants (POPs) and inorganic elements in predatory bird livers and eggs 2007 to 2009: a Predatory Bird Monitoring Scheme (PBMS) Report

The Predatory Bird Monitoring Scheme (PBMS; http://pbms.ceh.ac.uk/) is the umbrella project that encompasses the Centre for Ecology & Hydrology’s National Capability contaminant monitoring and surveillance work on avian predators. By monitoring sentinel vertebrate species, the PBMS aims to detect and quantify current and emerging chemical threats to the environment and in particular to vertebrate wildlife. Sparrowhawk livers were analysed for a range of persistent organic pollutants (POPs) and heavy metals. Sparrowhawks are studied because they have a wide distribution across the Britain and can be used as a sentinel species for the terrestrial environment. Mean PCB and mercury liver concentrations were below those thought to have an adverse effect on individual birds. Pollutants, such as mercury and PCBs, can affect development and hatchability. Therefore, the PBMS also monitors the levels of contaminants in the eggs of a range of species including those of conservation concern, such as golden eagle and the re-introduced white-tailed sea eagle. Other species that are monitored are the northern gannet, which is used as a monitor of the marine environment, and merlin that hunts in upland habitats. The residues measured in the eggs of golden eagle and gannets collected between 2007 and 2009 were below those thought to have an adverse effect, but some residues in individual merlin eggs were above concentrations suggested to be indicative of no effect concentrations for birds generally. Few white-tailed see eagle eggs are received for analysis by the PBMS but many of the eggs that have been analysed, including one of the eggs analysed for this report, have DDE, PCB and/or mercury concentrations above levels associated with adverse effects on bird embryos and hatching success. In terms of long-term trends, there has been a decline in congener sum PCB contamination in the eggs of most of the species that have been monitored, except for coastal nesting golden eagles. In contrast however, there has been no significant decline over time in PCB concentrations in sparrowhawk livers and concentrations of ‘Paris 10’ congener sum and PCB-TEQ concentrations have also largely remained unchanged in both livers and eggs since monitoring began in 1996. Evidence for changes over time in mercury concentrations in predatory birds or their eggs is inconsistent across the species monitored. Where a decline has been detected, it has occurred before approximately 1990 and remained largely unchanged since then

The Predatory Bird Monitoring Scheme (PBMS) Report 2006-7

The Predatory Bird Monitoring Scheme (PBMS) examines the levels of certain pollutants in selected wildlife species in Britain. It started in the 1960s to assess the impact of organochlorine pesticides on raptor populations, and the scheme is now the longest-running of its kind in the world. The aims of the PBMS are to monitor the levels of contaminants to determine how and why they vary between species and regions, how they are changing over time, and the risks they may have on individual birds and on their populations. Dead predatory birds are submitted to the PBMS by the public and by wildlife hospitals, veterinarian and zoological organisations. Eggs are collected, under licence, from a range of nests. The majority of these eggs are addled or deserted, although for some species, e.g. northern gannets, fresh egg are sampled. Second generation anticoagulant rodenticides (SGARs) are potentially toxic to all mammals and birds, and predators that feed upon rodents are particularly likely to be exposed to these compounds. Since 1983 the PBMS has monitored SGAR residues in barn owls, while kestrels have been monitored since 2001. The proportion of barn owls which have one or more SGARs in their liver increased from less than 10% in the 1980s to approximately 40% in the early 2000s. However, there has been a small decrease in this percentage in the last few years. A higher proportion of kestrels have detectable residues of SGARs in their liver than barn owls with 60% of birds received in the years 2001 to 2006 having one or more SGAR in their liver. There is no evidence of a change over time in the proportion ok kestrels with detectable liver SGAR residues. Overall, the high incidence of exposure amongst monitored species remains of concern. Sparrowhawk livers are analysed for a range of persistent organic pollutants (POPs) and heavy metals. Sparrowhawks are studied because they have a wide distribution across the Britain and can be used as a sentinel species for the terrestrial environment. Following restrictions on its use as an agricultural pesticide, mercury concentrations have declined in sparrowhawks. However, despite PCBs being banned in 1981, there has not been any long-term change in polychlorinated biphenyl (PCB) liver concentrations in sparrowhawks during the period 1968-2006. In herons, used as a sentinel species for freshwater habitats, both PCB and mercury concentrations have declined. In 2006, mean PCB and mercury concentrations in both species were below those thought to have an adverse effect on individual birds. Pollutants, such as mercury and PCBs, can affect development and hatchability.. Therefore, the PBMS monitors the levels of contaminants in the eggs of a range of species including those of conservation concern such as golden eagle and the re-introduced white-tailed sea eagle. Other species that are monitored are the northern gannet, which are used as a monitor of the marine environment, and merlin that hunt in upland habitats. In general, and specifically in 2006, the residues measured in the eggs of golden eagle and gannets are below those thought to have an adverse effect on bird eggs, but some residues in individual merlin eggs were at concentrations associated with effects in other species. Few white-tailed see eagle eggs are received for analysis by the PBMS but a large proportion of those eggs that have been analysed, including the egg collected in 2006, have DDE, PCB and mercury concentrations above levels associated with adverse effects on bird embryos and the hatching success of eggs. Despite the withdrawal of PCBs from manufacturing over 20 years ago, the evidence for declining PCB concentrations in predatory birds is equivocal, with declines in liver or egg residues in some species but not in others. Mercury concentrations in most species have not significantly changed during the monitoring period

PBMS archive holdings: a Predatory Bird Monitoring Scheme (PBMS) report

The Predatory Bird Monitoring Scheme (PBMS; http://pbms.ceh.ac.uk/) is the umbrella project that encompasses the Centre for Ecology & Hydrology’s National Capability contaminant monitoring and surveillance work on avian predators. By monitoring sentinel vertebrate species, the PBMS aims to detect and quantify current and emerging chemical threats to the environment and in particular to vertebrate wildlife. As part of its chemical monitoring studies the PBMS receives and carries out post-mortem examinations on approximately 300 birds or prey each year. A range of tissues are taken from the carcasses. Around 100 addled and deserted eggs from various species are also submitted to the PBMS. The eggs are cracked open and the contents collected. The shells are retained for two years prior to being donated to the National Museums Scotland for cataloguing and archiving. The main purpose for collecting tissues and egg contents is for use in annual monitoring of pollutant concentrations by the PBMS. However, not all samples are used each year for chemical analyses and, even when samples are used, typically only a sub-sample is analysed. Samples that are not analysed or for which only a sub-sample is analysed are retained in the PBMS archive. Overall, the number of samples in the PBMS archive is approaching 50,000 tissue and egg content samples. The material in the archive is used for research studies investigating chemical fate and behaviour, to trial new monitoring, and for a wide range of other studies, some of which are unrelated to pollutants. The purpose of this short report is to summarise the main holdings in the PBMS archive. This is done for the seven species for which we currently or used to obtain relatively large numbers of carcasses. We also draw attention to holdings of a small number of other species which may be of priority conservation concern. The information is broken down by type of sample that is held, the decade in which it was collected, and provenance as to whether samples were from England and Wales, or Scotland. In addition to information on numbers of samples from carcasses, we provide a description on the holdings for the number of egg contents for various species, again broken down by decade and provenance

Concentrations of perfluorinated compounds (PFCs) in northern gannet, Morus bassanus, eggs: a Predatory Bird Monitoring Scheme (PBMS) report

The Predatory Bird Monitoring Scheme (PBMS; http://pbms.ceh.ac.uk/) is the umbrella project that encompasses the Centre for Ecology & Hydrology’s National Capability contaminant monitoring and surveillance work on avian predators. By monitoring sentinel vertebrate species, the PBMS aims to detect and quantify current and emerging chemical threats to the environment and in particular to vertebrate wildlife. This report presents the results of a pilot study to quantify the concentrations of perfluorinated compounds (PFCs) in the eggs of the northern gannet, Morus bassanus, from the Ailsa Craig and Bass Rock colonies off the UK coast. The principle aim of this work determine the concentrations of PFCs that are accumulated in the eggs of gannets and whether there was any evidence of differences in accumulation between eggs from the two colonies studied. The egg contents were analysed by Liquid Chromatograph – Mass Spectrometry (LC-MS) techniques. Compounds from both the perfluorinated carboxylate and perfluorinated sulfonate groups of PFCs were quantified. PFCs were detected in all of the ten eggs analysed, with both carboxylate and sulfonate compounds present. Perfluorobutanoate (PFBA) and perfluorononanoate (PFNA) concentrations were both significantly higher in eggs from Ailsa Craig compared to those from Bass Rock but there was no difference between colonies in egg concentrations of sum PFC, sum carboxylate or sum sulphonate concengtrations. Overall data from this limited one year of sampling suggests that gannet eggs from both Ailsa Craig and Bass Rock contain relatively low concentrations compared to eggs from some other species that have been examined. Concentrations of perfluorooctane sulfonate (PFOS) were with an order of magnitude of residues associated with adverse effects [and for one egg from Bass Rock these levels were exceeded] but the majority of eggs from both colonies contained PFOS residues that exceeded a suggested predicted no effect concentration (PNEC) for this compound

Anticoagulant rodenticides in predatory birds 2012: a Predatory Bird Monitoring Scheme (PBMS) report

The Predatory Bird Monitoring Scheme (PBMS; http://pbms.ceh.ac.uk/) is the umbrella project that encompasses the Centre for Ecology & Hydrology’s National Capability contaminant monitoring and surveillance work on avian predators. By monitoring sentinel vertebrate species, the PBMS aims to detect and quantify current and emerging chemical threats to the environment and in particular to vertebrate wildlife. Anticoagulant rodenticides, and in particular second generation anticoagulant rodenticides (SGARs), can be toxic to all mammals and birds. Predators that feed upon rodents are particularly likely to be exposed to these compounds. The PBMS, together with other studies, has shown that there is widespread exposure to SGARs of a diverse range of predators in Britain and that some mortalities occur as a result. This report describes the PBMS monitoring for SGARs in barn owls (Tyto alba) found dead in 2012, summarises long term trends in exposure in this species, and compares the relative prevalence of SGARs in barn owls in England and Scotland. We also report the results of an initial investigation into SGAR contamination in 42 sparrowhawks (Accipiter nisus) found dead between 2010 and 2012. Sparrowhawks normally feed on birds and the aim of this investigation was to assess the potential importance of avian foodwebs in exposure of predators to SGARs. SGARs were detected in 87% of the 63 barn owls that were collected in 2012. The most prevalent compounds were difenacoum, bromadiolone and brodifacoum. The majority of the residues were low (< 0.1 µg/g wet weight). One owl was diagnosed as likely to have been poisoned by SGARs. Most of the sparrowhawk livers that were analysed had detectable liver SGAR concentrations, again mainly difenacoum, bromadiolone and brodifacoum (79%, 55% and 64% of birds, respectively). The proportion of sparrowhawks with detectable residues of one or more SGAR (93%) did not differ significantly from that for barn owls (86%) collected over the same time 2010-12 time period. Co-occurrence of multiple residues in the liver was common in barn owls and sparrowhawks (70% and 74% of birds respectively). Sparrowhawks had significantly lower liver sum SGAR concentrations than barn owls in those birds that had detectable residues. SGARs have been monitored in barn owls since 1983. Data on long-term trends have been adjusted to account for changes over time in sensitivity of analytical methods. This has meant that very low residues (<0.025 µg/g wet weight), which are now detectable, are not included in the time trend analysis. Overall, the proportion of both adult and juvenile barn owls with detectable liver concentrations of one or more SGAR has increased significantly over the course of monitoring. The proportion of barn owls with detectable SGAR residues over the period 1990-2012 was two-fold higher in England than in Scotland but residue magnitude did not differ between birds from the two areas