This environmental impact assessment for Kriegers flak ... - Vattenfall

102 PRESENTATION OF THE AREA
tion with studies of staging birds at Kriegers Flak.
These investigations ran for two years between
April 2002 and March 2004. An area of 505km² was
surveyed from ships at 35 occasions with a distance of
four km between the transections. Mammals have also
been surveyed by aeroplanes 21 times within an area of
560 km2, with a distance of two km between transactions.
In order to register possible existence of porpoises,
click-detectors of the type T-POD were at 15 occasions
positioned between one to three days from an anchored
ship during a total of 36 days.
During the whole period only three porpoises and
three grey seals were observed at Kriegers Flak. No
harbour seals were observed during the two year long
survey.
An extensive literature study of grey seal, harbour
seal and porpoises has been made in connection with
the above study by IfAÖ and the result thereof, together
with the investigations, are presented below.
11.6.5.1 Grey Seal
The grey seal is the biggest of the Swedish seal species.
It can reach three metres and weigh 300 kg. Females
are smaller than the males and can reach a length of
2 metres and weigh up to 200 kg. The grey seal gives
a grey impression with a lighter belly. The proÞ le of
the head is the most distinct feature in comparison
with other seals, with a straight line from head to nose,
which is quite long. The grey seal reaches an age of
25-35 years in wild conditions and up to 40 years in
captivity.
The natural habitat of the grey seal is concentrated
to the north-eastern Baltic and at the beginning of the
20th century there were about 100 000 in the area.
Since the grey seal competes with the Þ shermen for
Þ sh, it was pursued early on and the numbers declined
rapidly. In the middle of the 1980s’ the total number
was estimated to 1 500 individuals. The population
thereafter increased largely and was 7500 individuals
in 1999 (Sundberg & Söderman 1999). The population
along the Swedish south coast, Skåne, Småland
and Gotland, is estimated to 200 individuals (Helander
& Häkönen). At Falsterbo, there is a population of
grey seals, which was counted from land in 1996 and
estimated to 50 animals (Tielman & Heide-Jörgensen
2001).
In Danish waters 12 grey seals were observed during
2000 at Rödsand (Tielman & Heide-Jörgensen
2001). During the autumn 2000, also grey seal cubs
were identiÞ ed. It is unclear if they stem from Rödsand
or Falsterbo.
In 1990 grey seals had a resting place at Saltholm
in Öresund but when counting from the air in 2000, no
seals could be detected (Tielman & Heide-Jörgensen
2001).
Along the German Baltic coast there are no colonies
or resting places of grey seal as the grey seal was
extinguished in Germany during the 1920’s.
By monitoring grey seals with an implanted satellite
transmitter, it has been possible to conÞ rm that 95%
of grey seals move within an area with a radius of
36–196 km from the resting place at the western tip of
Rödsand, see red markings in the Þ gure on page 101.
The grey seal wanders in the Baltic were it regularly
crosses the Arcona Basin and is therefore assumed to
move in the waters at Kriegers Flak. The three observed
grey seals at Kriegers Flak probably belong to
the population based at Falsterbo since this is closer to
Kriegers Flak than Rödsand.
Grey seal uses areas close to the cost as well as
areas further out at sea for locating food. Kriegers Flak
could potentially be a food retrieving area for seals
from Falsterbo but as so few seals have been spotted
there, it is not very likely. The reason for this is probably
the intense trafÞ c in the area around Kriegers
Flak (60 000 ships a year, Þ shing and leisure boats not
included).