Evaluating the sustainability of a Cisco fishery in Thunder Bay, Ontario, under alternative harvest policies

North American Journal of Fisheries Management
By: , and 

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Abstract

Sustainable management of fish stocks is promoted through the application of management strategy evaluations (MSEs), providing information to managers on the relative performance of alternative management approaches (strategies) while accounting for uncertainty. In this study, we developed a simplified MSE of a stock of Cisco Coregonus artedi in Thunder Bay, Ontario, to determine both the sustainability of the current harvest control rule (i.e., a constant exploitation rate [U] of 10%) and the performance of alternative harvest control rules in meeting fishery objectives. Success in meeting fishery objectives was evaluated through attained yields, interannual variation in yields, magnitude of spawning stock biomass (SB), and the risk of reaching low SB—performance metrics established based on consultation with an advisory group to Lake Superior fishery managers. Our simulations explicitly accounted for uncertainty in the frequency of strong year‐classes being produced by Cisco, the stock–recruit relationship, stock abundance, and the sex‐specific nature of roe harvest. Assuming that future productivity is similar to the productivity observed over the period from 1985 to 2015, results suggest that the current U of 10% is sustainable in terms of maintaining SB above 20% of the unfished level. Variants of constant U control rules that included thresholds defining when U is to decrease as a function of SB increased yield, decreased risk, and increased the magnitude of SB at the end of the simulation period. However, these advantages came at the expense of greater interannual variation in yield. Constant catch control rules greatly underperformed constant U control rules in terms of magnitude in yield; however, they did reduce interannual variation in yield compared to constant Ucontrol rules. Furthermore, conditional versions of constant catch control rules (i.e., threshold stock sizes below which the catch limit was reduced) mitigated risks of staying at low stock size.

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Publication type Article
Publication Subtype Journal Article
Title Evaluating the sustainability of a Cisco fishery in Thunder Bay, Ontario, under alternative harvest policies
Series title North American Journal of Fisheries Management
DOI 10.1002/nafm.10290
Volume 39
Issue 3
Year Published 2019
Language English
Publisher Wiley
Contributing office(s) Great Lakes Science Center
Description 17 p.
First page 543
Last page 559
Country Canada
City Thunder Bay
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