00000nam 2200000zi 4500 9.957256 CaOODSP 20251201105919 m o d f cr mn||||||||| 251112t20252025qucab ob f000 0 eng d 9780660796789 CaOODSP eng rda CaOODSP eng eng fre n-cn-nf ln----- y2y2 Fs97-6/3733E-PDF Santo, Mélanie, author. Developing a gillnet based abundance-at-age index for 4RSw Atlantic herring / by Mélanie Santo, Elisabeth Van Beveren and Kim Émond. Mont-Joli, QC : Regional Sciences Branch, Quebec region, Pelagic and Ecosystemic Sciences Division, Fisheries and Oceans Canada, Maurice Lamontagne Institute, 2025. ©2025 1 online resource (v, 38 pages) : illustrations (chiefly colour), colour map. text txt rdacontent computer c rdamedia online resource cr rdacarrier Canadian technical report of fisheries and aquatic sciences, 1488-5379 ; 3733 Includes bibliographical references (pages 12-13). "In 2021, a new experimental gillnet survey was started in Northwest Atlantic Fisheries Organization (NAFO) divisions 4Sw and 4R in collaboration with local harvesters, with the goal of developing a new index of spring and fall spawning Atlantic herring (Clupea harengus). This document outlines the survey design, proposes an analytical approach for estimating abundance-at-age indices, and provides an initial assessment of index quality. A new gillnet selectivity model was developed to convert observed length-specific catch rates across multiple mesh sizes into stock abundance-at-length, which was transformed into abundance-at-age using age-length keys. The resulting age compositions successfully tracked dominant cohorts, appeared robust against sample variability in space and time, and aligned with other independent data sources. While the indices appear promising for informing age composition, estimates of overall abundance remain uncertain in part due to limited time series lengths. Additional years of data will help with index validation and clarify its role in future assessments"--Abstract, page iv. Includes abstracts in English and French. Atlantic herring Newfoundland and Labrador Atlantic Coast. Fish stock assessment Newfoundland and Labrador Atlantic Coast. Gillnetting Newfoundland and Labrador Atlantic Coast. Hareng Terre-Neuve-et-Labrador Atlantique, Côte de l'. Ressources halieutiques Évaluation Terre-Neuve-et-Labrador Atlantique, Côte de l'. Pêche au filet maillant Terre-Neuve-et-Labrador Atlantique, Côte de l'. Canada. Department of Fisheries and Oceans, issuing body. Maurice Lamontagne Institute, issuing body. Canadian technical report of fisheries and aquatic sciences ; 3733. (CaOODSP)9.504449 PDF 2.65 MB https://publications.gc.ca/collections/collection_2025/mpo-dfo/fs97-6/Fs97-6-3733-eng.pdf