130925-studie-wildlife-comeback-in-europe

% change
1500
1200
900
600
300
0
Figure 2.
Change in Grey
seal population
abundance by
decade and overall
change between
1977 and 2005. Please
note that due to the
way change was
calculated, decadal
change does not sum
to overall change.
Table 3.
Major reasons for
change in the status
of the Grey seal in
Europe.
to continue. Increases have also been detected in
Norway [32] , and the Baltic [42] , where the species has
not yet reclaimed all of its natural area of occurrence
[29] . There are, however, signs that growth is
levelling off in some areas. For example in the UK,
pup production has not increased in the north and
west of Scotland, which is believed to be the result
of a combination of reductions in the reproduction
and the survival of pups, juveniles or adults [7] . New
breeding colonies in the southeast of the country
are, however, expanding rapidly [7] , and further
research should attempt to identify the different
factors that are affecting seal colonies in these areas.
In addition, the species continues to be affected
by a number of threats, all of which are of anthropogenic
origin. For example, entanglement in nets
may be a larger issue than previously thought
and a considerable source of mortality in some
populations [43] . Environmental contaminants,
and chemical and oil spills will also continue to
be problematic [4] , and seals may also experience
increasing disturbance through a surge in coastal
recreation activities and ecotourism, especially at
haul-out and breeding sites [28] . In the Baltic Sea, for
example, recolonisation of former haul-out sites has
been hampered by increasing human activities [29] .
Rank Reason for change Description
1 Legislation The Grey seal became protected throughout its
European range in the 20th century [14] .
2 Species management –
Reduced exploitation and
persecution
3 Land/water protection
& management – Site
protection and ban of
DDTs/PCBs
1960s 1970s 1980s 1990s 2000–05 1977–2005
The species is listed on the Habitats Directive
Annexes II and V [19] and the Bern Convention [18] .
In the UK, an early hunting ban (as early as 1914)
resulted in increase in numbers [13] , which meant
that the Grey seal could recolonise the North Sea [13] .
There are protective measures in place to limit
harvest, culls, disturbance and by-catch in many
countries [3] .
Many seal conservation areas have been set up
throughout the species’ range, and the Grey seal
is protected within these sites, e.g. in the UK in
Sites of Special Scientific Interest (SSSIs) [40] and
Special Areas of Conservation designated under the
Habitats Directive [19] .
A decline in pollutant loads in the Baltic following
the ban on DDTs and PCBs in the 1970s [1] led to an
increase in Grey seal numbers [29] .
There are also novel threats emerging for
the Grey seal. For example, climate change is
believed to play an important role in the future
of the species. A worst-case-scenario prediction
of an 80% reduction in ice cover in the Baltic Sea
will negatively affect breeding conditions and
reproductive output of the seal population [4, 29] .
But climatic changes also have more immediate
consequences, as pup mortality rates are likely
to be affected by extreme weather events. For
example, pupping cave systems collapsed during
the pupping season in Cornwall in the UK in 2011,
and storm surges on pupping beaches and ledges
have washed large numbers of pups out to sea in
the Farne Islands [28] . In addition, the species may
be increasingly driven from sites through developments
in marine renewables such as coastal
and off-shore wind farms, as has been observed
at Scroby Sands in the UK [44] . Across Europe,
an increasing number of seals are found with
corkscrew lacerations, i.e. single cuts spiralling
down the body from the head, and often detaching
skin and blubber from the underlying tissue [7, 45] .
These are caused by being drawn through a new
type of ducted propeller, and although the level of
mortality is negligible in large populations, it may
well exacerbate declines in smaller colonies [7, 45] .
Despite the current and future threats described
above, the European population of Grey seal is
likely to grow further, especially as legislation
is strengthened. This will undoubtedly lead to
greater conflicts with fisheries, as many fishermen
continue to regard seals as the single biggest threat
to their livelihood [4] . The species is often killed
because of its reputation for feeding on commercially
important fish, damaging nets and traps,
and acting as vectors for parasites that can impact
fisheries [1] . In Finland, the majority of fishermen
consider the seal population too large, arguing that
the species is harmful to their livelihoods [4] . Despite
this animosity, many do recognise its importance
as an indicator species for the Baltic and an
important component of biodiversity [4] . Indeed,
there is little scientific or direct evidence of seals
damaging nets [28] , and the spatial overlap between
fisheries and seals is not as great as once thought [46] .
As a top marine predator, the seal may, in fact, play a
key role in the maintenance of healthy ecosystems
and thus commercially viable fish stocks [47] . If the
seal is to continue its recolonisation of the European
continent, these on-going conflicts will need to be
mitigated by the further development of seal-proof
fishing gear (which may also reduce by-catch
mortality), as well as the continued protection of the
species and its sites. In a landmark case in Scotland,
the first custodial sentence of 80 days for killing 21
seals was issued in 2009 to a local fisherman [48] .
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