EBFM "prototype" MSE in New England
Gavin Fay, Lisa Kerr, Emily Liljestrand, Jerelle Jesse, Madeleine Guyant
Goal: Demonstrate how MSE can be used to evaluate EBFM management strategies for a Georges Bank Ecosystem Production Unit.
Process:
- Worked iteratively with management committee and advisors as stakeholders
- Combined existing tools to evaluate EBFM procedures: Link multispecies model to MSE framework with built in single species assessment tools
Fundamental objectives:
- Maintain or increase inflation adjusted total value for the fishery
- Preserve ecosystem function and structure
- Maintain stock complex biomass around levels that optimize fishing opportunities
- Prevent overfishing
- Response of regulations to stocks at low abundance, and recovery of depleted stocks
- Reduce regulatory complexity
EBFM pMSE
Summary
Hydra: multispecies operating model conditioned on Georges Bank data within MSE framework as prototype test of EBFM strategies.
Results: additional flexibility and increased yield possible with EBFM "ceilings and floors" without increased risk to single stocks.
Operating model building blocks
Multispecies catch at length Hydra (Gaichas, et al., 2017)
Hydra-Associated GitHub repositories
- hydra-sim (Simulation Model Wiki): https://github.com/NOAA-EDAB/hydra_sim/wiki
- hydra-sim (pMSE/estimation fork): https://github.com/thefaylab/hydra_sim
- hydradata (mskeyrun fork): https://github.com/thefaylab/hydradata
- hydra-diag (diagnostics): https://github.com/thefaylab/hydra_diag
Groundfish MSE framework (Mazur, et al., 2023)
Groundfish MSE repository, branches, and tools
- main branch (including wiki): https://github.com/lkerr/groundfish-MSE
- pMSE branch: https://github.com/lkerr/groundfish-MSE/tree/JJ-EBFM
- includes ASAP model and Plan B smooth
- uses SAMtool state space surplus production assessment for complexes
- index-based "floors" for stocks within complexes
Setup
Management Alternatives
SS Static Single-species management, stock-specific assessment and catch advice.
SS Dynamic Single-species as above with dynamic reference points.
Feeding Complex Static Stock complex management and assessment: trophic complexes.
Feeding Complex Dynamic Stock complex as above with dynamic reference points.
Gear Complex Static Stock complex management and assessment: gear-based complexes.
Gear Complex Dynamic Stock complex as above dynamic reference points.
Static = full time series for reference points
Dynamic = most recent 10 years for reference points
Operating Model Scenarios
- Base
- Fleet dynamics (Adjust q for economic value)
- Initial biomass (Below base)
- Predator pressure (Increase M1 <30cm)
- Prey change (Increase other food)
Single species management alternatives
Multispecies management alternatives
Key takeaways
- Stock complex management resulted in higher and less variable catches (results below are for the trophic based complexes).
- Higher catches did not come at the expense of stock conservation status
- Catch closer to catch advice under stock complex management
- Results similar for different operating model initial condition scenarios:
red: high B, brown: high predators, green: high prey, blue: low B, purple: $F
Increased Predator Pressure (higher M1 on forage)
- More variable total annual catches
- Higher under-used quota
- Lower catches Increased Prey availability (more other food for modeled predators)
- All the above, plus fewer stocks below limits Price-based fleet dynamics (higher relative catchability on more valuable stocks)
- More stocks below limits
Relative performance of management alternatives
Points closer to the exterior edge indicate a better performance for the metric than points closer to the center.
- Stock complex management generally out preformed single species based management.
- Gear based complexes resulted in higher variability and more underutilized quota than the trophic based complexes.
Short term
First 5 years
of projection
Long term
Last 20 years
of projection
Outreach materials
Summary pages
- pMSE Overview
- Management Objectives and Performance Metrics
- Management Alternatives
- Results Engagement
- Operating Models
- Assessment Models
Thank you!
Additional Resources
EBFM pMSE June 2023 New England Council
- June Presentation
- September Update Presentation
- Final Report
- One Page Summaries
- ICES WGSAM sharepoint: Background Documents
References
Gaichas, S. K. et al. (2017). "Combining stock, multispecies, and ecosystem level fishery objectives within an operational management procedure: simulations to start the conversation". In: ICES Journal of Marine Science 74.2, pp. 552-565. ISSN: 1054-3139. DOI: 10.1093/icesjms/fsw119. URL: https://academic.oup.com/icesjms/article/74/2/552/2669545/Combining-stock-multispecies-and-ecosystem-level (visited on Oct. 18, 2017).
Mazur, M. D. et al. (2023). "Consequences of ignoring climate impacts on New England groundfish stock assessment and management". In: Fisheries Research 262, p. 106652. ISSN: 0165-7836. DOI: https://doi.org/10.1016/j.fishres.2023.106652. URL: https://www.sciencedirect.com/science/article/pii/S0165783623000450.
Slides available at https://noaa-edab.github.io/presentations
Contact: gfay@umassd.edu