Abstract
This document has been prepared by APEM on behalf of Beatrice Offshore Windfarm Ltd (BOWL). It outlines the methods and locations for the ongoing programme of benthic monitoring at Beatrice Offshore Windfarm (OWF) designed in accordance with the Conditions of the Beatrice OWF Section 36 consent (Condition 27) and the Marine Licence for the Offshore Transmission Works (OfTW), (Condition 3.2.1.1). The benthic monitoring strategy has been informed by a comprehensive review of monitoring requirements undertaken by RPS Energy, on behalf of BOWL in consultation with various stakeholders. This method statement covers the methods that will be used for the 2021 post-construction habitat survey and inspection of marine growth on, and in the vicinity of turbines of the Beatrice OWF.
To test the predictions of the BOWL Environmental Statement and Supplementary Environmental Information Statement (SEIS) and to facilitate an assessment of the timescales for the recovery of the MoeVen biotope in deeper water (i.e. the number, type and distribution of functions performed by organisms), grab sampling will be undertaken. The grab sampling for this post-construction survey will be conducted at the same locations sampled during the pre-construction surveys (10 locations within the OWF site and the two reference locations), (Appendix A: Figure A1) and will be an exact repeat of the 2020 post-construction grab survey. Samples will be collected for benthic infaunal analysis (i.e. species identification, enumeration and biomass determination) and for Particle Size Analysis (PSA). These data will be used to determine species community data and substrate types and allocate biotopes to each of the stations.
In addition, an underwater video survey will be carried out by a Remote Operated Vehicle (ROV) to provide a visual inspection of the four turbine foundations (each one comprised of a four legged jacket structure) which were surveyed in 2020. A Drop Down Video (DDV) survey also provided a visual inspection of the seabed extending hundreds of metres from these foundations during the 2020 campaign but these DDV transects are not proposed for the 2021 survey, with coverage up to a distance of 50 m proposed instead via the ROV. As faunal colonisation patterns may be different between foundations in the centre and along the border of the OWF, the four foundations were selected (during planning of the 2020 survey) in consultation with Marine Scotland to cover different areas of the OWF.
The underwater footage will be analysed to describe the epibiota communities associated with the turbine foundations, and to characterise the seabed habitat types and epibiota in the vicinity of the four turbine locations.