An evidence-based approach for selecting a limit reference point for Pacific herring (Clupea pallasii) stocks in British Columbia, Canada

Autor: Robyn E. Forrest, Allen R. Kronlund, Jaclyn S. Cleary, Matthew H. Grinnell
Rok vydání: 2023
Předmět:
Zdroj: Canadian Journal of Fisheries and Aquatic Sciences.
ISSN: 1205-7533
0706-652X
DOI: 10.1139/cjfas-2022-0168
Popis: A limit reference point (LRP) is defined as a level of biomass to be avoided with high probability, which should be selected to protect fish stocks from “serious harm”. We present an evidence-based approach for diagnosing serious harm and apply it to the selection of LRPs for five Pacific herring ( Clupea pallasii) stocks in British Columbia (BC). Natural mortality ( M) is estimated to be time varying and has increased more than it declined over the past three decades, which presents a challenge for estimation of equilibrium reference points based on maximum sustainable yield. We present a semi-empirical approach for developing LRPs, which examines surplus production in relation to spawning biomass to determine whether there is evidence for low productivity, low biomass (LP-LB) states consistent with serious harm. Three stocks showed evidence of persistent LP-LB states that resulted in periods of fishery closures. Based on these results, an LRP of 30% of unfished spawning biomass (0.3 B0) was recommended and adopted for management of all five major stocks of BC Pacific herring.
Databáze: OpenAIRE