Science Response 2020/037

Harvest Advice for Pacific Sardine (Sardinops sagax) in British Columbia Waters for 2020

Context

The northern subpopulation of Pacific Sardine (Sardinops sagax) in the eastern Pacific Ocean (California Current Ecosystem) has a distribution that can range between Baja California to southeast Alaska. In winter and spring months, most of this stock has the tendency to occur in waters off the California coast in association with spawning. Prior to, and during summer months, large aggregations of Pacific Sardine migrate from spawning habitat to more northern waters mainly to forage. Migratory patterns can be affected by age structure, population size and oceanographic conditions. Typically, most Pacific Sardines that migrate into British Columbia (BC) waters are the larger and older fish in the population. Pacific Sardine has not been fished in BC waters since 2012 due to reduced migration (a general absence of Pacific Sardine in BC waters) and formal fishery closures in 2015 to 2019.

Fisheries and Oceans Canada (DFO) adopted a harvest control rule in 2013 that applies a harvest rate to an estimate of age-1 year and older (age-1+) biomass that exceeds 150,000 t to calculate potential harvest options for the BC sardine fishery (DFO 2013). As described in the 2013 Science Advisory Report, a range in harvest rates from 3-5% was selected to calculate potential harvest options. The age-1+ biomass estimate used in the harvest control rule is acquired from the stock assessment conducted by the United States (US) National Marine Fisheries Service (NMFS) of the National Oceanic and Atmospheric Administration (NOAA).

A 2020 stock assessment review process occurred in February 2020 to provide direction on the development of a revised base model for the northern subpopulation of Pacific Sardine by the US NMFS (STAR 2020). In addition to implementing some methodological changes, the resulting 2020 stock assessment base model is informed by data sets representing fishery landings, biological sample data and fishery independent survey findings to December 2019 and generates stock status results and forecasts of age 1+ sardine biomass (Kuriyama et al. 2020).

DFO Fisheries Management requested that Science Branch incorporate the updated 2020 US stock assessment results of the northern subpopulation of Pacific Sardine (based on Kuriyama et al. 2020) into the 2013 BC fishery harvest control rule and provide harvest advice for Pacific Sardine for the 2020 season. Specifically, this Science Response (SR) provides information on the northern subpopulation of Pacific Sardine (associated with the California Current Ecosystem) current estimates of biomass, exploitation rates, and commercial landings to inform harvest options for the 2020 BC Pacific Sardine fishing season. Objectives of this report are to:

1. Report the results of applying the harvest control rule for a range of harvest rates from 0.03 to 0.05 in increments of 0.01, if the expected stock biomass is above the escapement buffer of 150,000 tonnes.
2. Identify uncertainties associated with this harvest advice.

A formal Canadian stock assessment was not conducted in 2020 so the following advice is based on the multi-year method approved in 2013 (DFO 2013). As such, for a full understanding of Science recommendations, uncertainties, and future considerations, readers are referred to DFO (2013).

This Science Response results from the Science Response Process of May 30, 2020 on Harvest Advice for Pacific Sardine (Sardinops sagax) in British Columbia Waters for 2020.

Science Response 2020/037 (PDF, 343 KB)

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