| Project data | |
|---|---|
| Project leader: | Prof. Prof. h. c. Dr Ursula Siebert |
| Scientific work: | Dr. Andreas Ruser, Dr. Klaus Lucke |
| Sponsorship: | Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety (funding code 0325117) |
Project description
Construction of offshore wind turbine generators (WTGs) in the German North and Baltic Seas is accompanied by extensive noise input to the marine environment. Sound energy emitted during construction is so high that the hearing of harbor porpoises is impaired or damaged, which may have sustained negative effects on the survival of these animals. Studies on a captive harbor porpoise during the MINOS+ project allowed for the first time to establish a threshold value for the auditory tolerance of the only whale species endemic to German waters.
The current project aims to validate this threshold value both in an additional captive harbor porpoise and several wild harbor porpoises to bolster strength of scientific evidence and thus also legal power. Other important project areas are the acoustic influence of different processes for driving of the foundations on the exposure threshold value for harbor porpoises.
Furthermore, the acoustic characteristics of sounds emitted during each ramming change with increasing distance to the construction site. The acoustic changeability of sound signals may have a significant influence on the exposure threshold value for harbor porpoises. A controlled sound emission experiment will serve to determine this connection quantitatively and to further secure the threshold value accordingly.
Auditory sensitivity is measured using the AEP method, the measuring of acoustic evoked potentials. A temporary threshold shift (TTS) is determined by measuring the normal auditory sensitivity of an animal, then exposing it to an intensive sound impulse (stimulating fatigue) and, afterwards, measuring auditory sensitivity again. If hearing capacity has (temporarily) significantly deteriorated in response to the loud sound, the reaction is called TTS.
