Feasibility assessment of bioclimate vulnerability approaches for priority marine migratory species in the Caribbean and Pacific UK Overseas Territories

Project Aims To assess the feasibility of applying bioclimate vulnerability assessment approaches to priority marine migratory species within the Caribbean UK Overseas Territories and the Pitcairn Islands. Building on previous work undertaken for JNCC, the study will evaluate the suitability of the proposed bioclimate vulnerability approach, consider relevant alternative approaches where appropriate, and determine whether sufficient evidence, data and expertise exist to support future implementation. 4. Project Background Climate change is increasingly affecting marine migratory species through changes in sea temperature, ocean productivity, habitat availability, ocean circulation patterns, species interactions and the frequency and intensity of extreme weather events (IPCC, 2022; Martay et al., 2023). These pressures may alter species distributions, abundance, migration routes and ecological relationships, with potentially significant consequences for biodiversity, ecosystem services and economies across the Caribbean Overseas Territories (OTs) and the Pitcairn Islands (IPCC, 2022; Martay et al., 2023). Evidence from marine vertebrates indicates that climate-driven changes in ocean conditions can alter migration timing, migratory routes, species distributions and access to suitable feeding and breeding habitats through changes in environmental conditions and prey availability (Kuletz et al., 2024). However, considerable uncertainty remains regarding how priority marine migratory species are likely to respond to future climate conditions and what these changes may mean for conservation and management (Martay et al., 2023). Previous JNCC work has reviewed available evidence on climate impacts affecting marine migratory species and identified a suite of priority species for further investigation. This work also highlighted the potential application of bioclimate vulnerability assessment approaches, which seek to combine information on species ecology, environmental change and climate pressures to better understand species vulnerability under future climate scenarios. However, uncertainty remains regarding the suitability of these approaches for the priority species and Territories, the data required to support their application, and whether resulting outputs would be sufficiently robust to inform management and decision-making. Previous work undertaken for St Helena, by Strathclyde University, explored ecosystem-based bioclimate vulnerability assessment approaches to project biomass declines in the marine protected area food web due to climate change (Olher et al., 2026). This study should consider the extent to which this and similar approaches may be applicable to priority species within the Caribbean Overseas Territories and Pitcairn. Consideration of alternative approaches should therefore be targeted and proportionate, focusing on whether an alternative method would offer a materially stronger basis for future implementation. The next phase of work is therefore to undertake a feasibility assessment that builds on previous work while critically evaluating the suitability of the proposed approach in comparison with other relevant assessment methods. This will include reviewing methodological requirements, assessing the availability and suitability of biological, ecological, environmental and climate datasets, identifying key evidence gaps and technical constraints, and determining the level of confidence that could be achieved through future assessments. The study will provide an evidence-based assessment of the most appropriate approach or approaches for application to priority marine migratory species, what analyses could be undertaken using currently available information, and what additional data, expertise or investment would be required to support future implementation. The findings will inform future implementation decisions and provide a roadmap for any subsequent climate vulnerability or bioclimate vulnerability assessment programme, supporting climate adaptation, marine conservation and environmental decision-making across the Caribbean Overseas Territories and the Pitcairn Islands. 5. Project Objectives To meet the overall aims of this project (Section 2), the objectives are: Objective 1 Review the proposed bioclimate vulnerability assessment approach and assess its suitability for application to priority marine migratory species within the Caribbean Overseas Territories and the Pitcairn Islands. Objective 2 Compare the proposed approach against a limited number of relevant alternative assessment approaches and identify the most appropriate option(s) for future implementation. Objective 3 Assess the feasibility of implementing the recommended approach for a priority list of marine migratory species supplied by JNCC. Objective 4 Identify key evidence gaps, data limitations, uncertainties and resource requirements associated with future implementation. Objective 5 Develop recommendations and an implementation roadmap for any future climate vulnerability or bioclimate vulnerability assessment programme. 6. Project Objectives: Detailed Tasks Objective 1: Review of the Proposed Assessment Approach The Contractor shall review the bioclimate vulnerability assessment approach identified through previous scoping. This shall include: • Review of the methodology and underlying assumptions. • Identification of biological, ecological, environmental and climate data requirements. • Assessment of technical and resource requirements. • Review of expected outputs and potential management applications. • Identification of strengths, limitations and uncertainties. Output: Review of proposed assessment approach. Objective 2: Comparison with Alternative Approaches The Contractor shall undertake a targeted review of alternative approaches that may be applicable to modelling climate impacts on marine migratory species. Relevant approaches may include: • Exposure-Sensitivity-Adaptive Capacity (ESA) assessments. • Trait-based vulnerability assessments. • Species distribution modelling approaches. • Climate envelope approaches. • Expert elicitation approaches. • Other approaches considered relevant by the Contractor. The Contractor shall: • Compare the approaches against the proposed bioclimate vulnerability assessment. • Assess relative strengths, weaknesses and data requirements. • Consider applicability to Caribbean Overseas Territory and the Pitcairn Islands contexts. • Recommend the most suitable approach or combination of approaches. Output: Assessment options comparison and recommendation. Note: The review of alternative approaches should be targeted and proportionate. It is anticipated that approximately 20% of overall project effort will be allocated to this task, with the majority of effort focused on feasibility assessment, species readiness, data availability, implementation requirements and decision-making utility. Objective 3: Species Feasibility and Data Readiness Assessment Using a priority species list supplied by JNCC, the Contractor shall: • Assess how the recommended approach would identify, infer or quantify the impacts of climate change on priority marine migratory species, including the pathways through which environmental and climatic change are expected to influence species vulnerability, distribution, abundance, behaviour or other relevant ecological responses. • Assess whether available data meet the minimum requirements of the recommended approach. • Review available ecological, occurrence, monitoring and climate information. • Determine whether sufficient evidence exists to support these linkages and identify key assumptions, uncertainties and evidence gaps. • Evaluate likely confidence levels achievable for each species. • Identify species suitable for immediate assessment. • Identify species requiring additional evidence or data mobilisation. • Identify species for which implementation is currently unlikely to be feasible. • Findings should be summarised in a species feasibility matrix. Output: Species feasibility and readiness assessment. Objective 4: Gap Analysis and Implementation Requirements The Contractor shall: • Identify critical evidence gaps. • Assess barriers to implementation. • Identify priority data collection and monitoring needs. • Determine resource, expertise and infrastructure requirements. • Identify opportunities for collaboration and data mobilisation. The Contractor should describe: • What could be delivered immediately using available evidence. • What could be delivered with targeted investment. • What could be delivered through a fully resourced future assessment programme. Output: Gap analysis and implementation roadmap. Objective 5: Decision-Making Utility Assessment The Contractor shall assess the likely value of future assessment outputs for conservation, adaptation and policy decision-making. This shall include consideration of: • Marine conservation planning. • Climate adaptation planning. • Environmental decision-making within the Territories. • Identification of outputs likely to support future ecological, social and economic impact assessments. Output: Decision-making utility assessment. Final Deliverables The Contractor shall provide: • Review of proposed assessment approach. • Assessment options comparison and recommendation. • Species feasibility and readiness assessment. • Gap analysis and implementation roadmap. • Decision-making utility assessment. Final feasibility assessment report including: • Recommended approach. • Applicability to priority species. • Implementation requirements. • Key evidence gaps. • Assessment confidence and limitations. • Recommendations for future assessment.