OFFSHORE BIODIVERSITY IMPACTS OF ENERGY PROJECTS

1. Introduction

Offshore energy projects—including offshore wind farms, tidal-stream installations, offshore oil and gas facilities, subsea cables and carbon-storage infrastructure—can create significant interactions with marine biodiversity. Potential effects include seabed disturbance, underwater noise, habitat loss, collision or displacement of birds, disturbance of marine mammals, changes to sediment movement, electromagnetic effects from cables, and cumulative impacts from multiple developments. UK law therefore requires biodiversity considerations to be integrated into environmental assessment and marine consenting. Offshore energy projects may require a marine licence, Electricity Act 1989 consent, Development Consent Order (DCO), Habitats Regulations assessment and species or habitat licences, depending upon the project and location.

2. Environmental Impact Assessment and Biodiversity

The Environmental Impact Assessment (EIA) process requires decision-makers to identify and assess significant environmental effects. Biodiversity is expressly included within the environmental factors that must be considered. For offshore projects, baseline surveys can cover benthic communities, fish, seabirds, marine mammals, protected habitats and ecological processes. Assessment should consider construction, operation, maintenance and decommissioning.

The Supreme Court's reasoning in R (Finch) v Surrey County Council [2024] UKSC 20 reinforces the importance of assessing legally relevant indirect effects within an EIA rather than artificially restricting the assessment to immediate physical effects. The judgment also recognises that environmental assessment legislation requires consideration of cumulative effects, biodiversity and reasonable alternatives.

3. Habitats Regulations and Protected Marine Sites

Where an offshore project may significantly affect a protected site, the Habitats Regulations impose additional safeguards. The Conservation of Offshore Marine Habitats and Species Regulations 2017 provide protection for offshore Special Areas of Conservation (SACs) and Special Protection Areas (SPAs) and establish assessment and licensing requirements for protected species. Where appropriate assessment is required, the competent authority must examine the implications of the project in light of the site's conservation objectives.

The precautionary principle is particularly important: uncertainty concerning ecological effects cannot simply be ignored when statutory protected-site requirements apply.

4. Cumulative and Ecosystem-Level Effects

Offshore biodiversity impacts frequently arise from several projects operating within the same marine ecosystem. Offshore wind farms, shipping, fishing, cables, oil and gas activities and other infrastructure may collectively affect the same species or habitat. Consequently, environmental assessment must consider in-combination and cumulative effects, rather than assessing every project entirely in isolation.

Current UK policy for renewable energy infrastructure specifically requires the Secretary of State to consider effects on marine ecology and biodiversity and permits monitoring requirements where available evidence is insufficient.

5. Case Law

Case Name/Citation

RSPB v Scottish Ministers [2017] CSIH 31, following the Outer House decisions concerning the Inch Cape, Neart na Gaoithe and Seagreen offshore wind projects.

Facts

The RSPB challenged consents for several offshore wind farms in the Forth and Tay region, raising concerns about impacts upon protected bird populations and the adequacy of environmental decision-making. The projects were authorised under the Electricity Act 1989 and marine environmental legislation.

Legal Issue

Whether the Scottish Ministers had lawfully discharged their environmental assessment obligations when granting consent.

Judgment

The Outer House granted the petitions and reduced the relevant consents. The Inner House subsequently considered the appeals and reinstated the consents, illustrating the importance of properly identifying the legal requirements governing environmental decision-making and the limits of judicial review.

Legal Principle/Ratio Decidendi

Environmental information must be properly integrated into statutory decision-making. Offshore renewable development remains subject to environmental and biodiversity safeguards despite its contribution to energy policy.

Significance

The litigation demonstrates that marine biodiversity, protected birds and environmental assessment are legally material considerations in offshore energy consenting.

6. Modern Biodiversity Governance

The UK is increasingly moving beyond harm avoidance towards restoration and compensation. The 2026 offshore-wind compensation framework addresses compensatory measures where protected sites are adversely affected. For energy NSIPs in England, biodiversity net gain becomes mandatory from 2 November 2026, although the current BNG regime for NSIPs does not extend to project components beyond the intertidal zone.

7. Conclusion

Offshore biodiversity regulation represents a balance between energy security, renewable-energy development and marine conservation. Effective legal governance requires robust baseline evidence, EIA, Habitats Regulations assessment, protected-species controls, cumulative-impact analysis, mitigation, monitoring and, where legally required, compensation. The central principle is that offshore energy development must be authorised through a decision-making process capable of identifying and addressing its ecological consequences.