Developing policy and practice for marine net gain.

Policies that require development projects to ensure no net loss (NNL) of biodiversity are becoming common globally. Momentum is increasing to extend this concept to one of net gain, including for the marine environment. While such policies are being formulated it is important to learn the lessons from NNL approaches and consider the wider opportunities presented by a net gain strategy. The vehicle for NNL is typically the mitigation hierarchy, which is applied through planning consents and licensing to projects expected to have significant environmental impact. However, it becomes clear that significant marine net gain is unlikely to be achieved by following this approach. Attempting site-based like-for-like compensation, restoration and enhancement is likely to result in only a minimal contribution towards aspirations for environmental recovery and addressing the climate and biodiversity crises. Moving forward with an effective net gain strategy will be a complex process, with challenges that range from a lack of data to the limitations presented by existing governance frameworks. In particular, the inadequate treatment of cumulative effects within the Environmental Impact Assessment process, and how regional marine planning can be better used to translate strategic objectives to the site level, need to be addressed. Taking the broader perspective of environmental (as opposed to biodiversity-only) net gain, and linking this to the natural capital approach offers advantages, and it is also essential that marine net gain considers species as well as habitats. Widespread marine net gain cannot occur independently of fisheries management, and extensive public engagement and stakeholder co-production is required to develop the necessary collaborative solutions.

Using stated preference valuation in the offshore environment to support marine planning.

This study presents valuations of components of marine natural capital that have hitherto been overlooked by the valuation literature. Using a discrete choice experiment, it values a set of ecosystem services linked to seabed natural capital in the UK section of the North Sea. The study focuses on offshore seabed habitats, using Good Environmental Status as a measure of seabed health, thus linking directly to management targets under the EU Marine Strategy Framework Directive. It considers how changing pressures on seabed habitats could affect marine industries and other ecosystems through trade-offs with (1) the contribution that exploitation of these habitats makes to the maritime cultural heritage; and (2) changes to the health of seabird populations. For seabed habitats and seabirds, the elicited values mainly represent non-use values for changes in the condition of natural capital assets. For maritime cultural heritage the valuation refers to the changed provision of this cultural ecosystem service. Results show that the public in England hold significant, strongly correlated, values for changes in the condition of offshore seabeds and seabird populations. Projected losses in maritime cultural heritage are found to lead to expected welfare decreases. Implications of these findings for marine planning and decision-making are discussed.

Global ecological, social and economic impacts of marine plastic.

This research takes a holistic approach to considering the consequences of marine plastic pollution. A semi-systematic literature review of 1191 data points provides the basis to determine the global ecological, social and economic impacts. An ecosystem impact analysis demonstrates that there is global evidence of impact with medium to high frequency on all subjects, with a medium to high degree of irreversibility. A novel translation of these ecological impacts into ecosystem service impacts provides evidence that all ecosystem services are impacted to some extent by the presence of marine plastic, with a reduction in provision predicted for all except one. This reduction in ecosystem service provision is evidenced to have implications for human health and wellbeing, linked particularly to fisheries, heritage and charismatic species, and recreation.

Developing conceptual models that link multiple ecosystem services to ecological research to aid management and policy, the UK marine example.

Our understanding of ecological processes that lead to ecosystem services is still evolving but ecological research aims to understand the linkages between the ecosystem and services. These linkages can affect trade-offs between different ecosystem services. Understanding these linkages, by considering multiple ecosystem services simultaneously supports management of the environment and sustainable use of resources. The UK marine environment is relatively data rich, yet the links between ecosystem and several ecosystem services and linkages between services are poorly described. A workshop with 35 marine scientists was used to create a conceptual model that links ecosystem components and key processes to four services they provide and to highlight trade-offs between them. The model was subsequently further developed to include pressures and mitigating management measures. The models are discussed in terms of their application to marine data to facilitate evidence-based marine management and their usefulness to communicate management measures with managers and stakeholders.