Birds in southern Öresund in relation to the wind farm at ... - Vattenfall

Introduction
Southern Öresund is an important staging and wintering area for a large number of waterfowl
species. Therefore Saltholm (on the Danish side) and Foteviken-Falsterbo (in Sweden) have
been appointed as ”Special Bird Protection Areas” (SPA) under the bird’s directive of the
European Union (79/409/EEG). Both these areas are also appointed as areas of international
importance under the Ramsar convention (www.ramsar.org). Other parts of the southern
Öresund, e.g. Lommabukten and Lundåkrabukten are also important for different wetland
species and show bird numbers higher than the criteria for international importance.
The southern part of Öresund is also an area where large numbers of migrating birds of
different species are passing both during spring and autumn. These parts probably hold the
largest concentrations of migrants in Scandinavia (Alerstam 1978, 1990) as this is where the
over-water passage over the Baltic between Scandinavia and the Danish islands (and in the
longer perspective the European continent) is shortest. This means that large numbers of
migrants arrive to Scandinavia from southerly and southwesterly winter quarters here in
spring, and that even higher numbers depart from Scandinavia over this area in autumn. The
migratory bird movements over the area have been studied for many years at Falsterbo Bird
Observatory (http://www.falsterbofagelstation.se/ ).
Based on this background, avian studies formed an important part of the Environmental
Impact Assessment when the Lillgrund Wind farm was planned in southern Öresund (Fig. 1).
A desktop study of the possible effects on the bird fauna of the planned wind farm was
published by Nilsson (2001). As a part of the conditions for the wind farm a monitoring
program was established to study the possible impact of the wind farm on the bird fauna.
The monitoring program included studies both on staging/wintering birds in the area and the
bird migration through the area. For staging/wintering water birds the study aimed to establish
whether the wind farm had any effects on their possibilities to utilize their feeding areas. For
actively migrating birds the program aimed at looking at if the wind farm affected the
migratory movements over the area, if there was any avoidance behavior that could lead to
increased costs for the birds or if there were any large risks for collisions with the turbines.
These questions were analyzed through studies performed before the construction and during
the first years of operation of the wind farm. Staging/wintering birds were counted from both
boat and aircraft both in the possible impact area, here defined as the area between the
Öresund Bridge between Sweden and Denmark and the Falsterbo peninsula and a reference
area south of Falsterbo (aerial surveys only), where we did not expect any risks for effects.
This latter part of the study was important to get background information on fluctuations in
numbers of staging/wintering water birds in the area.
Bird migration over the area was studied using data from two surveillance radar stations.
During the base-line studies visual observations of bird migration was conducted from a
neighboring vantage point (Green & Nilsson 2006). Background information of the general
bird migration over the area was also obtained from studies in connection with the Öresund
Bridge, just north of the wind farm area (Nilsson et al. 2009, 2010).
The first phase of the monitoring program (before the building of the wind farm) was
undertaken during 2001 – 2006 (Green & Nilsson 2006). There was no field work during the
construction period as it is clear that this work would lead to large disturbances on the birds
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