Response of harbor porpoises (Phocoena phocoena) to different types of acoustic harassment devices and subsequent piling during the construction of offshore wind farms
Before piling of offshore wind farm foundations, acoustic harassment devices (AHDs) are used to drive harbor porpoises out of the area where they could suffer injuries. Until 2017, a combination of pingers and seal scarer devices (usually SPL = 174-193 dB re 1 μPa (rms) @ 1m at 1 to 20 kHz depending...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Frontiers Media S.A.
2023-03-01
|
| Series: | Frontiers in Marine Science |
| Subjects: | |
| Online Access: | https://www.frontiersin.org/articles/10.3389/fmars.2023.1128322/full |
| _version_ | 1797865945292603392 |
|---|---|
| author | Julika Voß Armin Rose Vladislav Kosarev Raúl Vílela Ilse Catharina van Opzeeland Ilse Catharina van Opzeeland Ansgar Diederichs |
| author_facet | Julika Voß Armin Rose Vladislav Kosarev Raúl Vílela Ilse Catharina van Opzeeland Ilse Catharina van Opzeeland Ansgar Diederichs |
| author_sort | Julika Voß |
| collection | DOAJ |
| description | Before piling of offshore wind farm foundations, acoustic harassment devices (AHDs) are used to drive harbor porpoises out of the area where they could suffer injuries. Until 2017, a combination of pingers and seal scarer devices (usually SPL = 174-193 dB re 1 μPa (rms) @ 1m at 1 to 20 kHz depending on the device) was prescribed for mitigation purposes in Germany. However, seal scarers led to decreased porpoise detection rates in much larger distances than intended, when 750 m is usually rendered sufficient to avoid injuries. Therefore, devices specifically designed for mitigation purposes were developed and are prescribed since then. These acoustic porpoise deterrents (APDs; e.g. FaunaGuard Porpoise Module; SPL = 172 dB re 1 μPa (rms) @ 1m at 60 to 150 kHz) aim to keep the animals away from offshore construction sites but should not lead to large-scale disturbance as caused by a seal scarer. Although project-specific evaluations indicated that APDs are effective, a cross-project analysis and a comparison with data from previous piling procedures employing seal scarers were still pending. The present study aimed to fill this gap. Between March 2018 and April 2019, harbor porpoise detection rates were monitored acoustically in four offshore wind farm projects using CPODs before, during and after piling at different distances up to 10 km from piling. APD operation led to a significant decrease in detection rates in the vicinity of the device, indicating the displacement of the animals from a small-scale area. Depending on the wind farm, detection rates during APD operation decreased by 30 to 100% at 750 m distance compared to 6 hours before APD operation. Furthermore, reduced detection rates during APD operation were only observed up to about 2.5 km distance even when the APD was switched on for over 40 minutes. Given that the extent of disturbance to harbor porpoises is lower when using an acoustic porpoise deterrent compared to the seal scarer, we consider that preferential use of an acoustic porpoise deterrent is an improvement to mitigation strategies and an important step forward to a less harmful piling procedure. |
| first_indexed | 2024-04-09T23:17:26Z |
| format | Article |
| id | doaj.art-54b5dd6d8e904b93ba856f32dee5f84d |
| institution | Directory Open Access Journal |
| issn | 2296-7745 |
| language | English |
| last_indexed | 2024-04-09T23:17:26Z |
| publishDate | 2023-03-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Marine Science |
| spelling | doaj.art-54b5dd6d8e904b93ba856f32dee5f84d2023-03-22T05:56:53ZengFrontiers Media S.A.Frontiers in Marine Science2296-77452023-03-011010.3389/fmars.2023.11283221128322Response of harbor porpoises (Phocoena phocoena) to different types of acoustic harassment devices and subsequent piling during the construction of offshore wind farmsJulika Voß0Armin Rose1Vladislav Kosarev2Raúl Vílela3Ilse Catharina van Opzeeland4Ilse Catharina van Opzeeland5Ansgar Diederichs6BioConsult SH GmbH & Co. KG, Husum, GermanyBioConsult SH GmbH & Co. KG, Husum, GermanyBioConsult SH GmbH & Co. KG, Husum, GermanyBioConsult SH GmbH & Co. KG, Husum, GermanyOcean Acoustics Group, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, GermanyHelmholtz Institute for Functional Marine Biodiversity, Carl Von Ossietzky University Oldenburg, Oldenburg, GermanyBioConsult SH GmbH & Co. KG, Husum, GermanyBefore piling of offshore wind farm foundations, acoustic harassment devices (AHDs) are used to drive harbor porpoises out of the area where they could suffer injuries. Until 2017, a combination of pingers and seal scarer devices (usually SPL = 174-193 dB re 1 μPa (rms) @ 1m at 1 to 20 kHz depending on the device) was prescribed for mitigation purposes in Germany. However, seal scarers led to decreased porpoise detection rates in much larger distances than intended, when 750 m is usually rendered sufficient to avoid injuries. Therefore, devices specifically designed for mitigation purposes were developed and are prescribed since then. These acoustic porpoise deterrents (APDs; e.g. FaunaGuard Porpoise Module; SPL = 172 dB re 1 μPa (rms) @ 1m at 60 to 150 kHz) aim to keep the animals away from offshore construction sites but should not lead to large-scale disturbance as caused by a seal scarer. Although project-specific evaluations indicated that APDs are effective, a cross-project analysis and a comparison with data from previous piling procedures employing seal scarers were still pending. The present study aimed to fill this gap. Between March 2018 and April 2019, harbor porpoise detection rates were monitored acoustically in four offshore wind farm projects using CPODs before, during and after piling at different distances up to 10 km from piling. APD operation led to a significant decrease in detection rates in the vicinity of the device, indicating the displacement of the animals from a small-scale area. Depending on the wind farm, detection rates during APD operation decreased by 30 to 100% at 750 m distance compared to 6 hours before APD operation. Furthermore, reduced detection rates during APD operation were only observed up to about 2.5 km distance even when the APD was switched on for over 40 minutes. Given that the extent of disturbance to harbor porpoises is lower when using an acoustic porpoise deterrent compared to the seal scarer, we consider that preferential use of an acoustic porpoise deterrent is an improvement to mitigation strategies and an important step forward to a less harmful piling procedure.https://www.frontiersin.org/articles/10.3389/fmars.2023.1128322/fullPhocoena phocoenaGerman North Seaoffshore wind farmPassive Acoustic Monitoringdeterrencebehavior |
| spellingShingle | Julika Voß Armin Rose Vladislav Kosarev Raúl Vílela Ilse Catharina van Opzeeland Ilse Catharina van Opzeeland Ansgar Diederichs Response of harbor porpoises (Phocoena phocoena) to different types of acoustic harassment devices and subsequent piling during the construction of offshore wind farms Frontiers in Marine Science Phocoena phocoena German North Sea offshore wind farm Passive Acoustic Monitoring deterrence behavior |
| title | Response of harbor porpoises (Phocoena phocoena) to different types of acoustic harassment devices and subsequent piling during the construction of offshore wind farms |
| title_full | Response of harbor porpoises (Phocoena phocoena) to different types of acoustic harassment devices and subsequent piling during the construction of offshore wind farms |
| title_fullStr | Response of harbor porpoises (Phocoena phocoena) to different types of acoustic harassment devices and subsequent piling during the construction of offshore wind farms |
| title_full_unstemmed | Response of harbor porpoises (Phocoena phocoena) to different types of acoustic harassment devices and subsequent piling during the construction of offshore wind farms |
| title_short | Response of harbor porpoises (Phocoena phocoena) to different types of acoustic harassment devices and subsequent piling during the construction of offshore wind farms |
| title_sort | response of harbor porpoises phocoena phocoena to different types of acoustic harassment devices and subsequent piling during the construction of offshore wind farms |
| topic | Phocoena phocoena German North Sea offshore wind farm Passive Acoustic Monitoring deterrence behavior |
| url | https://www.frontiersin.org/articles/10.3389/fmars.2023.1128322/full |
| work_keys_str_mv | AT julikavoß responseofharborporpoisesphocoenaphocoenatodifferenttypesofacousticharassmentdevicesandsubsequentpilingduringtheconstructionofoffshorewindfarms AT arminrose responseofharborporpoisesphocoenaphocoenatodifferenttypesofacousticharassmentdevicesandsubsequentpilingduringtheconstructionofoffshorewindfarms AT vladislavkosarev responseofharborporpoisesphocoenaphocoenatodifferenttypesofacousticharassmentdevicesandsubsequentpilingduringtheconstructionofoffshorewindfarms AT raulvilela responseofharborporpoisesphocoenaphocoenatodifferenttypesofacousticharassmentdevicesandsubsequentpilingduringtheconstructionofoffshorewindfarms AT ilsecatharinavanopzeeland responseofharborporpoisesphocoenaphocoenatodifferenttypesofacousticharassmentdevicesandsubsequentpilingduringtheconstructionofoffshorewindfarms AT ilsecatharinavanopzeeland responseofharborporpoisesphocoenaphocoenatodifferenttypesofacousticharassmentdevicesandsubsequentpilingduringtheconstructionofoffshorewindfarms AT ansgardiederichs responseofharborporpoisesphocoenaphocoenatodifferenttypesofacousticharassmentdevicesandsubsequentpilingduringtheconstructionofoffshorewindfarms |