University Events

Description: Department of Fisheries Oceanography

"Portfolio Theory: an Important Tool For Ecosystem-Based Fisheries Management"

By: Fiona Edwards

Advisor: Steven X. Cadrin (University of Massachusetts Dartmouth)

Committee Members
Gavin Fay (University of Massachusetts Dartmouth), Lauran Brewster (University of Massachusetts Dartmouth),
Jason Link (National Marine Fisheries Service)

Thursday January 9th, 2025
1pm
SMAST East 101-103
836 S. Rodney French Blvd, New Bedford
and via Zoom

Abstract:

Traditional single-species fisheries management does not account for multi-species interactions and has not always performed well for avoiding overfishing or rebuilding many fisheries. Considering these interactions has become increasingly important for effectively managing fisheries because of climate change and divergent stock trends. Ecosystem-based fishery management (EBFM) is a more holistic approach to fisheries management which has gained traction over the last several decades. EBFM considers the biological, physical, and social-economic components which may influence fisheries. Implementing EBFM requires new tactics that can be informed by interdisciplinary research. One way risk associated with achieving a target reward has been analyzed in the finance field analysis is through portfolio optimization whereby the financial risk of a portfolio is minimized for given levels of return based on portfolio covariance. A set of fishery stocks’ landing values can be analyzed similarly to a set of financial assets in an investment portfolio. In this study, a candidate fisheries portfolio is analyzed for New England demersal species caught in the same fisheries. The sensitivity of this portfolio to data decisions such as species composition and time series length is investigated by developing efficient frontiers for different sets of fishery stocks and different time periods. Efficient frontiers were developed using portfolio optimization techniques from the finance field and adding harvest constraints to account for limits on harvesting in fisheries. Sensitivity analyses showed that risk estimates were sensitive to both species’ exclusion and time series selection. Examination of the changes in the frontiers to different periods of the time series characterized by regional shifts in management strategy allowed for evaluation of the degree of flexibility afforded to fishers during these times. Efficient frontier analyses based upon historic landings data indicated that the same target revenue could have been achieved with less or similar risk had a portfolio approach to management been taken for these species. Portfolio effects as applied to fisheries management can provide additional catch stability through increased diversification of multispecies fisheries and can reduce the risk of foregone revenue, all of which make it an important tool to consider for implementing EBFM.

Join Zoom Meeting https://umassd.zoom.us/j/94065204146

Note: Meeting passcode required. To request the Zoom passcode or for any other questions, please email Callie Rumbut at c.rumbut@umassd.edu