BSEP116B Biodiversity in the Baltic Sea - Helcom

of the Gulf of Finland (from 1 400 bp in 1994 to
3 800 in 2006), in Lithuania (from 900 bp in 1995
to 3 700 in 2006), and in Kaliningrad (from 120 bp
in 1991 to 8 500 in 2005). No increase has been
recorded in Latvia, where only 200–300 bp have
been nesting since the mid-1990s.
Population size
600000
500000
400000
300000
Flyway population
Estonia spring population
The total number of breeding pairs of great cormorants
in the Baltic Sea littoral countries amounted
to about 157 000 bp in 410 colonies in 2006, with
almost 80% of the birds breeding in Denmark,
Germany, Poland and Sweden 4 . All large colonies
in the Baltic Sea area are located near to the coast.
The largest colonies are found around the highly
eutrophic estuaries of the large rivers: Vistula
Lagoon (11 500 bp in 2006 in a colony on Vistula
Spit, Poland), Odra lagoon (10 750 bp in 2006 in
five colonies in Mecklenburg-Western Pomerania
and Poland), and Curonian Lagoon (11 300 bp in
2006 in two colonies on the Lithuanian and the
Kaliningrad side of the lagoon).
Some Baltic countries have initiated management
actions to control breeding numbers in order to
reduce conflicts with fisheries or to protect salmon
smolts. These actions include oiling or pricking of
eggs in ground-nesting colonies, scaring of birds
attempting to found new colonies, and shooting
of cormorants around fish ponds, lakes or fishing
devices. Illegal persecution is also reported from
several countries.
200000
100000
0
1958 1963 1968 1973 1978 1983 1988 1993 1998 2003 2008
Figure 4.3.3. Development of the flyway population and Estonian spring
population of the barnacle goose 1959–2008 (Eichhorn et al. 2009).
Number of breeding pairs
6000
5000
4000
3000
2000
1000
0
1971
Öland
Gotland
1974
1977
1980
1983
1986
Figure 4.3.4. Number of breeding pairs of barnacle goose in the main Baltic
colonies on Gotland and Öland, Sweden. The first breeding pair in the Baltic
Sea was recorded in 1971. Reductions in the number of breeding pairs in
2003 and 2006 are due to the presence of foxes on major breeding islands.
1989
1992
1995
1998
2001
2004
2007
Barnacle goose (Branta leucopsis)
During past decades, the East Atlantic flyway
population of barnacle geese, which consists of
the Arctic Russian population, the temperate Baltic
population and the temperate North Sea population,
increased in numbers from about 20 000
birds in 1959/1960 to about 550 000 birds in
2005/2006 (Ganter et al. 1999, Eichhorn et al.
2009, Figure 4.3.3). Birds of the Russian population,
which is by far the largest, use the Baltic
Sea coast for foraging during spring and autumn
migration. Birds belonging to the recently established
Baltic population breed mainly in colonies
along the coasts of Gotland and Öland in Sweden,
Saaremaa in Estonia, and in southern Finland
4
Numbers include inland colonies; for Germany, only the
Baltic Federal States Mecklenburg-Western Pomerania and
Schleswig Holstein are considered, for Russia the St. Petersburg
and Kaliningrad regions.
(Larsson et al. 1988, Black et al. 2007, Mikkola-
Roos et al. 2008). Smaller breeding colonies are
also found in mainland Sweden, Denmark, and
Germany.
The Baltic breeding population was established
naturally in 1971 on Laus holmar off the eastern
coast of Gotland. During the 1970s, the colony
increased in numbers and consisted of 125 bp in
1982. In 1981, the first breeding pair was observed
at the coast of Saaremaa, and in 1982 the first
breeding was recorded on Öland. During the
1990s, the number of colonies increased considerably
along the coasts of Gotland, Öland, Saaremaa
and southern Finland. In 2002, about 5 300 pairs
bred on more than 20 different small islands off
Gotland and Öland. Since then the overall number
of breeding pairs has decreased owing to the presence
of red foxes on some of the breeding islands
in some years (Figure 4.3.4). In addition to fox
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