Climate-fisheries dynamics: Individual-based end-to-end sea scallop model with socio-economic feedbacks

Introduction/rationale — Climate-ocean physical-biological models have great potential for advancing ecosystem-based fisheries management, but they have yet to be fully applied in this context. Science input to fisheries management for the NESLME remains largely based on individual species stock assessments, but a deeper understanding of the underlying ecological processes is critical for developing adaptive management strategies in a variable and changing climate. The proposed modeling study will implement a new ecologically based approach with adaptive fisheries management in the NESLME, providing insights into how scenarios of future climate change could impact fisheries in this region. The proposed study focuses on the sea scallop Placopecten magellanicus fishery, in economic terms one of the most important fisheries in the region. The biological characteristics and ecological role of the sea scallop make it a logical species for testing the capabilities of our proposed approach.

Objectives/work summary — The overall objective of this proposal is to gain insights into the impacts of climate change on the NESLME sea scallop fishery and to characterize adaptive management strategies that are robust to climate variability and change. The proposed end-to-end scallop model will be built on an existing modeling system, in which concentration-based lower food-web and individual-based larval transport models have been incorporated a high-resolution 3D hydrodynamic model to study climate-forced ecosystem dynamics, plankton production, connectivity, and recruitment success in the NESLME. The proposed study will extend our individual-based full-life-cycle model of sea scallops to examine multi-scale forcing on system productivity, recruitment, and adult stock size. This biological-physical model will be coupled with a socioeconomic model to assess the potential for adaptive management strategies to achieve reference points comprising measures of fishery performance, such as yield, net present value, spawning biomass, or employment, among others. The regional physical model is contained within a global ocean model, which provides boundary conditions and multi-scale physical forcing. A physical hindcast has been completed for the period 1978-present and is currently used in ocean forecasting. An existing hindcast of lower-food web dynamics will be extended to cover the period 1978-present. An individual-based, full-life-cycle model of sea scallops will be used together with historical data on sea scallop distributions to develop a 40-yr hindcast for this species. The coupled model will be used to examine effects of temperature, food, and ocean acidification on scallop dynamics and stock size. Scenarios of future climate change (IPCC RPC2.6 and RPC8.5) will be used to develop probabilistic forecasts of the ecosystem and sea scallop stocks in the NESLME from the present out to 2100. A bioeconomic model framework, including adaptive management strategies of the sea scallop fishery, will be implemented to evaluate the effects of climate and stock changes on the achievement of alternative measures of fishery performance, including fishing location, revenue and cost, fishing port geography, and fishing community vulnerability.

Relevance – The proposed study directly addresses the six priorities of this NESLME competition and the objectives of NOAA’s Next Generation Strategic Plan and Fisheries Climate Science Strategy. The comprehensive modeling approach, linking climate to ecosystem-based fisheries management and socioeconomics, is the top priority for the Northeast Regional Action Plan. The project advances the integration of climate impacts into NOAA fisheries stewardship.