Howell Marine Consulting (HMC) and Environmental Resources Management (ERM) were contracted by Natural England (NE) to assess potential frameworks that could be used to measure ecological losses and gains from development in the marine environment and in doing so, to support Defra and NE in the development of Marine Net Gain (MNG) policy. Expert advice on market-based approaches was provided by economics for the environment (eftec).
The work has focused on activities below Mean Low Water, but with consideration of how this aligns with the Biodiversity Net Gain (BNG) approach in the intertidal area, particularly for developments that might straddle both the intertidal and subtidal.
The aim of Phase 1 of this project (desk-based review) was to assess how ecological losses and gains could be measured, for habitats and mobile species (birds, fish and mammals), within an MNG regulatory framework and develop options that can be practically delivered. The project has focused on technical constraints for measuring ecological loss and gain and used expert opinion to identity what would be operationally possible. The project has also highlighted where there are further considerations that need to be explored, such as whether options are legally, politically or economically feasible.
Phase 2 of the project (see Section 4 for more details) tested the shortlisted frameworks from Phase 1 against real world scenarios, from a scientific, useability and deliverability perspective. This report details our recommendations for the development of an MNG assessment framework based on the outputs from this testing.