130925-studie-wildlife-comeback-in-europe

3.15. Grey seal
Halichoerus grypus
Summary
With a formerly continuous distribution along
the European coast, the Grey seal started to
decline in abundance and range from the late
middle ages due to human pressures, particularly
overexploitation. Over the past 50 years,
the species has been able to recover in much
of its former range because of legal protection.
However, anthropogenic threats such as conflicts
with fisheries continue to be a problem, and the
species is also likely to be increasingly affected by
climate change in the future.
Background
General description of the species
The Grey seal (Halichoerus grypus) is divided
into two subspecies (H. g. grypus in the Atlantic,
H. g. macrorynchus in the Baltic Sea) [1] . There are
three populations – West Atlantic (North America),
East Atlantic (Europe) and Baltic – that differ
in size [2] , breeding habitat [3, 4] , pupping dates [1] ,
weaning mass and lactation duration [2] . Seals
are generalist feeders, often foraging hundreds
of kilometres offshore [5] , and their diet varies
with location and age. In Europe, Grey seals feed
demersally [6] , mainly from the seabed to depths
of 100 m [7] . Sandeels are the main prey, but
other species such as gadids (white fish) are also
consumed [8] . The species is active day and night
on land [9] , and may travel very long distances [10]
between haul-out sites, where it rests and moults,
and specific breeding colonies, which are used
considerably less frequently at other times of the
year [11] . During the breeding season, males defend
territories in these colonies in order to mate with
oestrous females [9] . Pup mortality may be as
much as 15%, but can increase to 40 to 60% up to
the age of 12 to 18 months [12] depending on habitat
quality, birth site, maternal care, predation and the
amount of male-male aggression [1] .
Distribution in Europe
The Grey seal was historically much more
widespread than today [13] , with a continuous distribution
along mainland Europe [14] . Gradual declines
due to human interference [14] , particularly intense
hunting pressure [13] , started in the late Middle
Ages in the Wadden Sea and late 19 th century in
the Kattegat-Skagerrak. At present, the Eastern
Atlantic population is centred around the UK and
Ireland. Grey seals also occur in Iceland, the Faroe
Islands, along the European mainland coast from
the Kola peninsula to the south of Norway, and
from Denmark to Brittany [1] . The Baltic population
resides in the Baltic Sea only [1] , and has been reproductively
isolated since at least the Last Glacial
Maximum [15, 16] .
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