Selective harvesting under a changing climate

Feedback mechanisms between fishing decisions and reproductive dynamics pose a challenge for effective fisheries management. Size-dependent pricing is common in fisheries and can result in the selective harvesting of a population subset, often differentiated by size or sex. In the mid-Atlantic blue crab fisheries, research suggests that market incentives to harvest large male crabs may negatively affect population dynamics. The temperature dependence of blue crab biology and the broader impacts of climate change introduce further complexities in managing this fishery. In this paper, we simulate the effect of selective harvesting on the Delaware Bay blue crab population and compare the behavioral response of fishers to various policy and warming scenarios.
We develop a unique bioeconomic model that links size-dependent market incentives to population productivity to assess how policies and warming scenarios could affect the sustainability of the fishery. Temperature dependent crab growth is simulated using an individual-based population model, which we link to an economic model in which fishers maximize the net present value of harvest by choosing levels of effort for each market category distinguished by shell status, size, and sex. Our model captures intra-seasonal dynamics by incorporating different marginal costs of fishing, prices, and gears used at different points in the season. This approach allows us to evaluate the potential long-term impacts of different management strategies under varying warming conditions, ensuring that both the economic viability and ecological health of the blue crab fishery are considered.