Since 2000, the number of seabirds breeding around the UK has
declined by over 600,000 or 9%, a report by the Joint Nature
Conservation Committee (JNCC), the Government’s advisers on UK
nature conservation, has revealed.
The recent decline follows years of poor breeding performance
that have occurred with greater frequency since the mid 1990s and
have been widely reported in the press. “These latest figures
on breeding numbers demonstrate the magnitude of the effect these
poor seasons have had on the UK seabird population” said Dr Matt
Parsons, one of the reports authors. “They represent a ‘turning of
the tide’ for seabirds breeding in the UK, which increased in
number from around 4.5 million in the late 1960s to 7 million by
the end of the 1990s”.
Recent declines have tended to be greater in species that feed
on shoals of small fish, such as lesser sandeels. For instance,
there are now 40% fewer black-legged kittiwake and 33% fewer
European shags breeding in the UK than in the late 1960s.
Even greater declines have been seen at some of Scotland’s
largest seabird colonies; Deryk Shaw, Warden of the Fair Isle Bird
Observatory in Shetland said “Breeding kittiwake numbers have been
falling for many years now and there was no reprieve in 2008. A
whole island count found that the number of nests is only half of
that counted as recently as 2005 with many birds just standing on
bare ledges”.
The cause of these declines is almost certainly a shortage of
food that has led to lower numbers of adults surviving from one
year to the next, and not enough chicks being produced and
surviving to replace them.
The reasons for the shortages of sandeels in recent years are
complex and not fully understood. Over-fishing off eastern
Scotland did have a significant detrimental effect on the
productivity of kittiwakes at nearby colonies during the 1990s, but
little fishing has occurred within foraging range of these colonies
since then. Fishing may be affecting the distribution and
abundance of sandeels across the entire North Sea, but it is not
clear whether this has affected the availability of sandeels to
seabirds feeding closer inshore. There is a growing body of
evidence that sandeel shortages are also caused by increasing sea
temperatures as a result of climate change. Sea temperatures
around the UK have been rising since the 1980s by around 0.2-0.9˚C
per decade. These rises are thought to have been responsible
for striking changes in the abundance of plankton – the tiny
floating organisms that sandeels and other small fish feed on.
Long-term declines in numbers of black-legged kittiwakes and
other species that rely on sandeels, are expected to continue
unless the recent rises in sea-surface temperature are reversed.
Reversing the recent warming of the oceans is reliant on the
success of global efforts to combat climate change. However, in
their report, JNCC identified two other man-made pressures – from
fishing and from the introduction of non-native mammals to island
seabird colonies - that could be managed in the short-term to
mitigate the impacts of climate change.
For instance, the maintenance of an existing ban on sandeel
fishing off eastern Scotland appears to have been effective by not
exacerbating the existing impacts of climate change.
The eradication of non-native mammals that eat seabird eggs and
chicks, from seabird islands has resulted in the expansion of
existing seabird colonies and in the re-colonisation by seabird
species that previously nested there. On Lundy, in the Bristol
Channel, rats were eradicated in 2004. Since then the seabirds have
increased into new nesting areas. David Appleton of Natural
England, said “Since we removed the rats, burrow-nesting species
such as Manx shearwater and Atlantic puffin now have a safe home in
which to raise their young.” The Manx shearwater population on
Lundy increased from 166 pairs prior to the eradication to 1000
pairs in 2008.
As the 2009 breeding season gets underway, seabird biologists
and amateur birdwatchers are currently monitoring events as part of
the Seabird Monitoring Programme, eager to see what is in store for
seabirds this year.
- ENDS -
Notes for Editors:
- UK Seabirds in 2008 is a booklet summarising the
results of the UK Seabird Monitoring Programme (SMP). Led by
JNCC, the programme co-ordinates the monitoring of seabird breeding
numbers and breeding success throughout the UK. Data from the
Republic of Ireland is also collated, to set the results in a wider
geographical context. Download UK Seabirds in 2008 booklet.
- The following organisations are partners with
JNCC in the SMP: Scottish Natural Heritage, Countryside Council for
Wales, Natural England, Environment Agency - Northern Ireland,
Royal Society for the Protection of Birds, Centre for Ecology and
Hydrology, The National Trust for Scotland, The Seabird Group,
Shetland Oil Terminal Environmental Advisory Group, BirdWatch
Ireland, National Parks and Wildlife Service (Dept. of Environment,
Heritage and Local Government – Republic of Ireland).
- Much of the information of the SMP is collected by volunteers,
some of whom are helped with expenses made available via the
Seabird Group (for which, see http://www.seabirdgroup.org.uk/
).
- The Joint Nature Conservation Committee (JNCC) is the
statutory adviser to Government on UK and international nature
conservation. Its work contributes to maintaining and enriching
biological diversity, conserving geological features and sustaining
natural systems. JNCC delivers the UK and international
responsibilities of the Council for Nature Conservation and the
Countryside, the Countryside Council for Wales, Natural England and
Scottish Natural Heritage.
Further information:
General media enquiries should be directed to the
(Peterborough): Tel:
01733 866839
Fax: 01733 555948
For an interview with the project co-ordinator, or answers to
technical questions, please contact
(JNCC, Aberdeen): Tel
01224 655715
Images:
The following digital images may be obtained from JNCC
Communications:
|
Atlantic puffin carrying sandeels
(Photograph by Bob Perry)
|
|
|
European shag
chicks
(Photograph by Ken
Plows)
|
 |
| Northern
gannets
(Photograph by Bob Perry)
|
|
|
Common tern chicks from the cache of an
American mink on an island in Argyll &
Bute
(Photograph by J.C.A. Craik)
|
|
JNCC News Release 11/06/09