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2021, Strategic Net Gain Task and Finish Group, Offshore Wind Evidence and Change Programme,  Strategic Net Gain Targets for Coastal  and Marine Environments

2021, Strategic Net Gain Task and Finish Group, Offshore Wind Evidence and Change Programme, Strategic Net Gain Targets for Coastal and Marine Environments

Topic categories:

Benthic Ecology


Epifauna and Fish

Marine Mammals


Last series update:

October 2021

MEDIN approved



Collection date:



Offshore Wind Evidence and Change Programme (OWEC)

Publication date:

Oct 2021


The Crown Estate




There is increasing recognition of the need for greater action to restore the marine  environment in the face of a continued decline in marine biodiversity. Net gain has been identified as a potential approach to development which can contribute to halting and reversing biodiversity loss by leaving the natural environment in a measurably better state than before. Developments which adopt Biodiversity Net Gain (BNG) aim to have positive impact by delivering an overall increase in biodiversity.

Currently, there is no formal requirement for Net Gain as part of marine development or Nationally Significant Infrastructure Projects in the marine environment. However, it is understood that both are likely to become mandatory in the near future. Introducing a system of Net Gain in the marine environment is recognised as being particularly challenging owing to the dynamic nature of the marine environment and the complex interactions with marine development. It is therefore important that there are clear objectives and targets for Marine Net Gain (MNG) which provide a focus for developer action.

Defra’s Offshore Wind Enabling Actions (OWEAP) Programme is working to increase understanding of the environmental impacts of offshore wind and find strategic solutions to manage and mitigate impacts in order to reduce barriers to the expansion of offshore wind in English waters. One of the key areas being addressed under OWEAP is MNG. 

In order to help inform the development of Defra policy in relation to MNG and its implementation, the Offshore Wind Evidence and Change Strategic Net Gain Task and Finish Group (T&F Group) was established to work closely with OWEAP to identify suitable targets for marine and intertidal Net Gain. The T&F Group comprised a range of organisations including Defra, Energy UK, Natural England, Renewable UK, RSPB, SUDG, The Crown Estate, The Wildlife Trusts and UK Major Ports Group, supported by an experienced consultancy, ABPmer. 

The Group aimed to identify a set of strategic targets for the delivery of MNG and, through consultation, achieve agreement for these targets from all sectors. The T&F Group began by undertaking a gap analysis of existing legal and policy objectives and targets, to inform and support discussion around possible priorities for MNG. Following this, two on-line stakeholder surveys were conducted to gather views from marine stakeholders about MNG opportunities and priorities. The findings from these surveys informed the suggested recommendations for MNG priorities.

In addition, to ensure that the T&F Group was operating with a common understanding the Group defined a set of assumptions that would guide the work discussions. The assumptions outlined were central to the Group’s determination of targets whilst also informing their application and deliverability by industry to meet potential future MNG obligations. The development of these assumptions was supported by the information gathered through the stakeholder surveys. It is also important to stress that all discussions of the T&F Group on MNG were based on the foundation that the mitigation hierarchy will still apply to development.

The outcome of the work carried out by the T&F Group is a robust set of suggested strategic targets for MNG, which have strong consensus and agreement from all sectors; industry, regulators and conservation bodies. The targets set a clear direction for how developments could contribute towards MNG to restore and improve the marine environment, linked to national strategic priorities. On a national and regional level, the T&F Group considers that MNG should be a strategically managed process led by the government to which funding and delivery of projects is contributed to by industry. 

Importantly, MNG should not just encompass habitat restoration but also include species restoration and human activity pressure reduction, as important measures to support restoration and enhancement of the marine environment.