Using age compositions derived from spatio-temporal models and acoustic data collected by uncrewed surface vessels to estimate Pacific hake (Merluccius productus) biomass-at-age

• DOI: 10.3389/fmars.2023.1214798
• Publication Date: 2023-09-11T12:23:41Z
• Authors: Derek G. Bolser; Aaron M. Berger; Dezhang Chu; Steve de Blois; John Pohl; Rebecca E. Thomas; John Wallace; Jim Hastie; Julia Clemons; Lorenzo Ciannelli
• Keywords: Merluccius; Stock assessment

Generating biomass-at-age indices for fisheries stock assessments with acoustic data collected by uncrewed surface vessels (USVs) has been hampered the need to resolve backscatter contemporaneous biological (e.g., age) composition data. To address this limitation, Pacific hake ( Merluccius productus ; “hake”) were gathered from a USV survey (in 2019) and acoustic-trawl (ATS; 2019 eight previous years), fishery-dependent non-target (i.e., not specifically targeting hake) fishery-independent sources (2019 years). overcome lack of sampling in survey, age class compositions estimated generalized linear mixed spatio-temporal model (STM) fit The validity STM estimation procedure was assessed comparing estimates ATS each year. Hake all combinations acoustics (USV or 2019, only other years) information (STM Across area, proportional derived best differed observations 0.09 on average (median relative error (MRE): 19.45%) 0.14 across years (MRE: 79.03%). In data-rich areas regular fishery operations), 0.03 11.46%) 54.96%). On average, total biomass using composition-based approximately 7% study period (~ 3% given same source When different ATS) compared data, differences nearly ten-fold greater (22% 27%, depending if used). STMs non-contemporaneous may provide suitable assigning population structure areas, but advancements processing automated echo classification) be needed generate viable USV-based biomass-at-age.