The Wildlife and Pollution contract covers a long-term
monitoring programme, the Predatory Bird Monitoring Scheme (PBMS),
that examines the levels of certain pollutants in selected wildlife
species in Britain. The programme was started in the early 1960s,
when there were serious concerns over the effects of organochlorine
insecticides and organomercury fungicides on various species of
birds and mammals. This early work demonstrated the effects of the
organochlorines and eventually contributed to the ban on their use
in the UK and abroad. The programme has subsequently assessed the
success of these bans by measuring whether there has been a decline
in the concentrations of organochlorine pesticides in the livers
and eggs of predatory and freshwater fish-eating birds.
Investigations have also been made into the levels of industrial
polychlorinated biphenyls (PCBs), following their identification as
pollutants in 1966. Mercury levels, derived from both agricultural
and industrial sources, have also been tracked, although mercury
concentrations were not measured in birds collected in 2001. In
recent years, investigations have been made into the effects of the
newest generation of rodenticides on barn owls
Tyto alba.
Northern gannet
Morus bassanus eggs are also collected
approximately biennially from two colonies and, when available,
from other sites; eggs were last collected in 2002.
This programme is now the longest-running of its kind anywhere
in the world and the findings stimulate considerable interest
internationally, as well as in Britain. Annual reports give an
interim summary of results and every three years these annual
results are gathered together into a more substantial report in
which they are integrated with previous findings. The latest report
of this type covers the period up to and including 2000 (Shore
et al., 2005a). Results are published periodically in the
scientific literature. This current report presents the results of
analyses carried out on material collected in 2002 and the findings
of novel work areas agreed in the 2002/2003 work programme.
The Wildlife and Pollution contract has been subject to
regular scientific assessments within JNCC’s rolling programme of
peer review. As a result of these, some monitoring activities have
been modified, so as to allow the initiation of new studies and
reorientation of the PBMS so that remains focused on current
chemical risks. Most notably, common kestrels Falco
tinnunculus are no longer monitored for organochlorines and
the intensity of monitoring for organochlorines in sparrowhawks has
been reduced. However, kestrels have been monitored for
second-generation anticoagulant rodenticides since 2001. This is
because an individual study, carried out as part of the PBMS
activities, demonstrated that this species may be particularly
vulnerable to exposure to these compounds (Shore et al.,
2001). Furthermore, new studies have been initiated to
investigate potential risks from other chemicals, such as
polycyclic aromatic hydrocarbons (see section 8 of this report),
and these studies draw on the whole range of material submitted by
volunteers to the PBMS.
The core PBMS samples used for chemical monitoring are body
tissues from the carcasses of sparrowhawk Accipiter nisus,
grey heron Ardea cinerea, barn owl Tyto alba,
kestrel Falco tinnunclulus, red kite Milvus
milvus, and the eggs of merlin Falco
columbarius, golden eagle Aquila chrysaetos, sea
eagle Haliaeetus albicilla and gannet Morus
bassanus. Carcasses and eggs of other predatory bird
species (such as peregrine falcon Falco peregrinus, common
buzzard Buteo buteo, long-eared owl Asio otus,
little owl Athene noctua, common kingfisher Alcedo
atthis, great crested grebe Podiceps cristatus, and
great bittern Botaurus stellaris) which do not form the
core part of the PBMS but are sent to the Centre for Ecology &
Hydrology (CEH) by volunteers, are not analysed chemically.
However, post-mortem examinations are carried out the carcasses,
relevant information is recorded and the cause of death is
determined (and reported back to the volunteer who submitted the
carcass). Samples of the egg contents and body organs for these
species, and those that do form part of the core monitoring, are
all archived at -20°C as part of the unique PBMS tissue and egg
sample archive (see section 12 of the current report). This
is an invaluable resource and is often used in specific targeted
research studies (for example, see section 11 of the current
report).
Each section within the Wildlife and Pollution contract is
summarised below. Each is dependent on the provision of material
from amateur naturalists and other interested parties, and it is
not always possible to obtain desired material for analysis,
especially from remote areas. The results from the core
monitoring of organochlorine and mercury concentrations in the
livers and eggs of various species and of second-generation
anticoagulant rodenticides in barn owl and kestrel livers are
summarised in sections 1.2-1.6 and in section 1.7,
respectively. The aims and results of novel areas of work on
polycyclic aromatic hydrocarbon concentrations in eggs, unknown
compounds in liver tissues, and spatial variation in liver PCB
concentrations in terrestrial species are summarised in sections
1.8, 1.9, 1.10, and 1.11, respectively. Updates on the role of the
PBMS in monitoring decabromodiphenylether concentrations in
predatory birds and on the cataloguing of the PBMS tissue and egg
archive are summarised in sections 1.11 and 1.12.