Quantifying harbour porpoise disturbance by offshore windfarm piling activities ...

• Main Authors: Haelters, Jan, Vigin, Laurence, Degraer, Steven
• Format: Conference Object
• Language: unknown
• Published: ASC 2012 - Theme session O 2024
• Subjects: Technologies and data; Pressures, impacts, conservation, and management; Harbour porpoise
• Online Access: https://dx.doi.org/10.17895/ices.pub.24974715.v1; https://ices-library.figshare.com/articles/conference_contribution/Quantifying_harbour_porpoise_disturbance_by_offshore_windfarm_piling_activities/24974715/1

No abstracts are to be cited without prior reference to the author.The impact of pile driving on marine mammals is one of the major environmental concerns in offshore windfarm construction. We assessed the impact of pile driving on the spatiotemporal distribution of harbour porpoises during the season of maximum abundance in Belgian waters. We combined data collected by a small number of passive acoustic monitoring (PAM) devices, moored inside and outside the project area, and five standardized aerial surveys, covering the Belgian part of the North Sea (±3600 km²). The combination and integration of both techniques proved very useful as PAM results in low spatial but high temporal resolution data, while aerial surveys have a complementary low temporal but high spatial resolution. Just before construction activities started, aerial surveys yielded an estimate of 2.5 harbour porpoises per km², while after the start of the construction (piling) activities density estimates had decreased to 1.3 animals per km². ...