Distribution, biomass, and demographics of coastal pelagic fishes in the California Current Ecosystem during spring 2021 based on acoustic-trawl sampling

This report provides: 1) a detailed description of the acoustic-trawl method used by NOAA’s Southwest Fisheries Science Center (SWFSC) for direct assessments of the dominant coastal pelagic fish species (CPS), i.e.: Pacific Sardine Sardinops sagax, Northern Anchovy Engraulis mordax, Pacific Mackerel Scomber japonicus, and Jack Mackerel Trachurus symmetricus in the California Current Ecosystem (CCE) of the west coast of North America; and 2) estimates of the biomasses, distributions, and demographics of those CPS encountered in the survey area between 20 March and 13 April 2021. The core survey region, which was sampled by NOAA Ship Reuben Lasker (hereafter, Lasker), spanned most of the continental shelf between San Diego and San Francisco, California (CA). Throughout the core region, Lasker sampled along transects oriented approximately perpendicular to the coast, from the shallowest navigable depth (~30 m) to offshore distances of ~75 nmi in the Southern CA Bight (SCB) and ~35 nmi between Point Conception and San Francisco. To estimate the CPS biomasses in the nearshore region, where sampling by Lasker was deemed inefficient, unsafe, or both, fishing vessel (F/V) Long Beach Carnage sampled to ~10 m depth along 5-nmi-long transects spaced 5 nmi apart between Point Conception and San Diego, and around Santa Cruz and Santa Catalina Islands in the SCB.