CEFAS24-06 Contract for Sabellaria spp. monitoring surveys with an ARIS Camera

Background: The Sizewell BEEMS (British EDF Estuarine and Marine Studies) programme is funded by Sizewell C Limited (SZC). Through this programme, Cefas provide authoritative scientific information on the marine and transitional waters in the vicinity of the consented SZC new build nuclear power station and require a competent supplier to deliver the element described below. Overview of Requirement: Cefas require a supplier to conduct a subtidal Adaptive Resolution Imaging Sonar (ARIS) camera survey for the Sizewell C (SZC) Nuclear New Build project to prepare for construction activities. At SZC there are known offshore areas of the reef forming polychaete Sabellaria spp. The turbid waters in the Greater Sizewell Bay preclude the use of traditional underwater camera, however the seabed in the region has previously been successfully imaged with an ARIS camera (Sound Metrics ARIS Explorer 3000). Previous survey work, including ARIS camera imagery acquired at Sizewell is detailed in the SZC Environmental Statement Appendix 22C for further background context. The objective of the proposed survey is to ground-truth an area of the seabed with an ARIS camera (Sound Metrics ARIS Explorer 3000) to confirm the seabed type and the presence or absence of Sabellaria spp. tube aggregations. The specified 'Sound Metrics ARIS Explorer 3000' is required to ensure quality and data consistency with the previous survey, and therefore it is a requirement for the supplier to either own, or be able to hire, the equipment for the survey. The exact survey area will be derived from a preceding (separate) side scan sonar and bathymetry survey (anticipated Spring 2024), and therefore the exact survey area is not known, however the expectation is that it will be in the region of the offshore infrastructure (Figure 1), approximately 3 km offshore off Sizewell, in approximately 10-20m of water. The survey area is likely to be approximately 1.5 km x 1 km (1.5 km2) and is expected to cover a range of habitats including subtidal sand, subtidal rock (Coralline Crag) and subtidal biogenic reefs (Sabellaria). The survey is required in the Summer of 2024.