Evaluating Consequences of Alternative Harvest Policies for Atlantic Menhaden and the Impacts on their Predator Atlantic Striped Bass
Genevieve M. Nesslage
2020 - 2022
University of Maryland Center for Environmental Science
Michael Wilberg, University of Maryland Center for Environmental Science, Chesapeake Biological Laboratory
Strategic focus area:
Sustainable fisheries and aquaculture
Atlantic menhaden (Brevoortia tyrannus) is a migratory forage fish that plays a vital role in Chesapeake Bay and Mid-Atlantic marine ecosystems by linking production at lower trophic levels with piscivorous predators. Given the critical ecosystem services menhaden provide as forage, the Atlantic States Marine Fisheries Commission is currently developing an Ecosystem-Based Fisheries Management (EBFM) approach to stewardship of the menhaden resource. Managers and stakeholders are particularly interested in potential impacts of menhaden management on its primary predator, Atlantic striped bass (Morone saxatilis).
Our research will provide scientific guidance on best practices for setting menhaden harvest policies that meet EBFM goals for the stock. For this project, we will conduct a performance evaluation of a suite of alternative harvest control rules (HCRs) for menhaden using a linked, age-structured, predator-prey simulation model of menhaden and striped bass. HCRs provide quantitative guidelines for changing fishery quotas in response to stock conditions and fishery performance. Our simulation study will examine both the direct effects of alternative menhaden HCRs on the menhaden stock and fishery performance as well as the indirect effects of menhaden HCRs on the striped bass stock and fishery, including striped bass body condition.
This project will provide fisheries managers with scientific guidance on best practices for adopting the HCR policy that will most likely achieve their EBFM objectives for the menhaden fishery. Our modeling tool will assist managers in evaluating tradeoffs among fishery objectives such as stability in menhaden and striped bass biomass, risk of overfishing menhaden and striped bass, stability in striped bass fisheries catch, and striped bass health. Our project is novel in that it will consider the impact of both predation mortality and stochasticity in recruitment on the performance of alternative harvest control rules for Atlantic menhaden and its impact on the striped bass stock and fishery.