BATMOVE

To date there has been a lack of information about bat migration over the sea needed to reliably estimate the possible impacts of offshore wind turbines. The project aims to create a framework for developing suitable measures to reduce and prevent collisions with offshore wind turbines by bats migrating over the sea. In particular this includes improved knowledge of the spatial and temporal distribution and the migration paths of bats across the North and Baltic Seas as well as assessing recording methods and developing an evaluation methodology.

Methods

Assessment of existing data on bat migration over the North and Baltic Sea region should supply an initial overview of phenology, spatial distribution, weather dependency, predictive capability, behaviour around anthropogenic structures and the incidence of collisions. As there is little experience so far with suitable methods for the offshore recording of bats, potential methods will be tested and evaluated.
Building on these results, a research concept will be developed that is adapted to the situation in the German North and Baltic Seas, and a study of bat migration undertaken in selected areas in the North and Baltic Seas. This includes research on the origins and routes of migrating bats.

The information obtained will serve as an initial basis for developing an evaluation method for bat migration.

At onshore wind turbines measures have been established for reducing collisions such as switch-off algorithms. An evaluation will be made as to whether methods like these can be transferred to offshore wind turbines.
The results will be presented at regional and interregional conferences and made available to an expert audience at an international expert event towards the end of the project term. A final report will be produced.

The project enabled the testing of methods for acoustic recoding of bats at offshore sites. Initial results from the bioacoustic recordings confirm that bats regularly migrate across the sea. The presence of bats was confirmed during the migration periods in spring and late summer at almost all the offshore sites fitted with recording devices. High activity levels were recorded, especially above the Baltic Sea north of Rostock in the Kadet Trench and the Arkona Basin as well as over the North Sea on Heligoland.