Last year there were over 700 wind turbines in the Baltic Sea, the majority of them in German and Danish waters, and according to the prepare for wind energy production in the future years, the location of wind farms will be increased to more than 27,000 square kilometers, Marko Mägi, a bird ecologist at the institute of ecology and geosciences of the University of Tartu and senior professional at the Environmental Board (Keskonnaamet), composed in his blog (link in Estonian).
Each of the wind farms covers a big location and has a considerable eco-friendly effect, particularly on types’ environments. Therefore, overseas wind farm preparation needs info on types incident, migration and environment usage, he said.
In addition to changing feeding and nesting environments, wind turbines likewise block bird migration. Due to the problem of acquiring appropriate information, which needs precise tracking of migratory bird habits, the death rate in crashes with overseas wind turbines is just a price quote.
A more precise representation would require an extensive understanding of migration rate, instructions and elevation, in addition to per hour and seasonal variations. Scientists began to gather this info utilizing GSP transmitters.
Due to massive and long-lasting population losses throughout the whole East Atlantic Flyway, the curlew is a near-threatened types. Even though breeding curlews prevent encounters with onshore wind farms, they are amongst the most threatened moving birds due to the danger of hitting onshore wind farms.
Between 2018 and 2021, the migration of the Eurasian curlew, whose population has actually drastically decreased, was kept track of utilizing GPS transmitters as the types passed overseas wind farms. The birds were tagged in 4 various nations: Germany (Wadden Sea), France (Atlantic coast), Estonia and Finland.
The information collected from 51 people, consisting of 6 birds that embedded in Estonia, showed that their migration path generally passes through the Baltic Sea. When returning from wintering premises in western Europe in the spring, a considerable part of the migration occurs over the sea and just 6 percent over land.
Specifically in the western part of the Baltic Sea, the course of the the curlew goes through wind farms, and most of wind farms that have actually been already built are located along the curlew’s main migration path.
The Eurasian curlew moves usually at elevations listed below 250 meters: lower over the sea than on land, and greater in the spring than in the fall. Consequently, an accident with a wind turbine, within the rotor’s working radius, is extremely possible. The blade of the highest wind turbine at the minute reaches 188 meters; the most affordable height is just 20 meters above water level.
The scientists argued that as innovation advances and brand-new turbines end up being progressively more powerful, the blades of future turbines will reach 150 to 300 meters in height, while mean of migration height was 60 meters in fall and 150 meters in spring.
Overall, this recommends that in between 65 and 75 percent of the Eurasian curlew’s fall migration happens at elevations where there is a risk of crash with a wind turbine.
In the spring, the figures are in between 50 and 62 percent, and even lower, at 27 to 37 percent, if migration listed below the rotor’s working radius is omitted.
The greatest peak of the Eurasian curlew’s spring migration happens in between April 16 and April 25, representing 59 percent of the spring migration.
From mid-June to mid-July is the peak of fall migration. It is likewise understood that the migratory Eurasian curlew is most active in the late night, in the evening and early in the early morning, when the bird flies at a typical speed of 56 kilometers per hour and somewhat quicker in the evening than throughout the day.
In the exact same method, the scientists understand that the spring migration happens at specific very same time and does not alter for many years, due to the fact that it is mainly identified by genes. Therefore, they argue it is possible to shut off wind turbines throughout the peak migration duration and minimize the danger of crashes.
Nevertheless, the fall migration is more distributed in time, making bird-friendly management of wind turbines an uphill struggle.
The issue is likewise appropriate to other shorebirds that utilize the Wadden Sea to refuel prior to moving throughout the Baltic Sea to their north-eastern breeding premises.
Most overseas wind farms are presently found within the 25 percent and half core home-variety, in which curlews invested high percentages of their time moving at turbine height, and a considerable boost in this overlap can be anticipated if prepared future wind farm situations are recognized.
Sensitive sea locations for curlews lie especially in the nearshore south-western Baltic Sea and the surrounding mainland, although the latter might be of less issue offered the substantially greater flight elevations throughout the land.
At the conclusion of the research study the investigates desire that especially delicate and condensed migration durations throughout spring need to be urgently thought about in relation to possible limitations to turbine operation times.
Given the big locations reserved for overseas wind power generation in the Baltic Sea, the present research study recommends that marine spatial preparation for overseas wind farms should take into consideration the possible loss of bird biodiversity.
The research study is released in Animal Conservation.
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