Macroalgae 2022 - 2023 Participants:
| Organisation | Opportunistic macroalgae cover ring test (OMC-RT) | Opportunistic macroalgae biomass ring test (OMB-RT) | Country |
| Cyfoeth Naturiol Cymru / Natural Resources Wales | 1 | 2 | UK |
| DAERA Environment, Fisheries and Marine Group Laboratory | 1 | 1 | UK |
| Environment Agency | 9 | 8 | UK |