Science Response 2021/034

Harvest Advice for Pacific Sardine (Sardinops sagax) in British Columbia Waters for 2021

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 2020.

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).

The 2021 assessment of the northern subpopulation of Pacific Sardine by NMFS occurred in April 2021. The coastal pelagics acoustic-trawl survey that was intended to be a main source of information in assessment efforts was cancelled in 2020 due to the coronavirus disease (COVID-19) pandemic. Recognizing the information gaps from not having survey information, a catch-only projection model was planned for generating results for use in 2021. However, due to complications associated with fitting a catch-only model with catch information for Mexico, the catch-only assessment method was not endorsed and results from the 2020 base assessment were recommended for use in 2021 instead (Kuriyama et al. 2020, Pacific Fishery Management Council 2021).

DFO Fisheries Management requested that Science Branch incorporate the most recent stock assessment estimate of age-1+ biomass for the northern subpopulation of Pacific Sardine into the DFO sardine harvest control rule.

The 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; and
2. Identify uncertainties associated with this harvest advice.

A formal Canadian stock assessment was not conducted in 2021 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 reports results from the Regional Science Response process of May 31, 2021 on the Harvest Advice for Pacific Sardine (Sardinops sagax) in British Columbia Waters for 2021.

Science Response 2021/034 (PDF, 335 KB)

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