Notes from the field – 30th June 2025
In early March almost half of the St. Andrews-based Sea Mammal Research Unit (SMRU) Consulting team were away from the office on field-related work. In one effort we had a team of four in Cromarty setting up 30 passive acoustic monitoring (PAM) moorings that were deployed later that month as part of the Dogger Bank Wind Farm (DBWF) initiative for a passive acoustic monitoring (PAM) study. The DBWF Project is located between 125 and 290km off the east coast of Yorkshire, extends over approximately 8660km² and water depths range from 18m to 63m.
1. The SMRU Consulting team in Cromarty preparing C-PODs for deployment
The aim of the DBWF PAM study is to collect data on porpoise acoustic presence and underwater noise levels at various distances from piling locations to build on existing work on this topic (e.g., Benhemma-Le Gall et al. (2024), Graham et al. (2019)). The primary objective is to provide scientific data to validate the PrePARED project work of Benhemma-Le Gall et al. (2024) by gathering data, specific to the UK-portion of the southern North Sea, around the development of Effective Deterrence Ranges (EDRs) for unabated piling in relation to noise management within harbour porpoise Special Areas of Conservation.
Additionally, the data will measure underwater noise levels during piling activities and investigate changes in porpoise acoustic presence concurrent with impact piling as a function of distance, received noise levels, and other covariates (e.g. vessel presence). This will be used to assess how porpoise respond as a function of received noise level, i.e. to estimate dose-response functions for porpoise to piling.
The PAM moorings were prepared in Cromarty and shipped to Middlesborough for mobilisation. Alongside a team from SMRU Consulting with assistance from Hughes SubSea Services and Subacoustech all 30 moorings were deployed in 3 days in mid-March from the vessel Wind Evolution.
2. One of the DBWF PAM study moorings being deployed
All moorings are now collecting baseline data ahead of piling at the DBWF wind farm site and during the piling. The instruments will remain in the water until recovery in August, with a plan to publish the results in a project specific report and scientific paper.
This initiative is funded by Dogger Bank Wind Farm with additional support from Defra and the Crown Estate as part of their Piloting of Offshore Wind Environmental Mitigation (POWEM) project, part of the Offshore Wind Evidence and Change Programme. We are grateful for support of PrePARED project colleagues from the University of Aberdeen’s Lighthouse Field Station in Cromarty and the Marine Directorate’s Marine Lab in Aberdeen.
Check back for updates on the planned mooring recoveries at the end of August and data analysis later this year.