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Assessment Framework for Atlantic Herring (Clupea harengus) Stocks on the West Coast of Newfoundland and the Lower North Shore of Quebec (NAFO Divisions 4RSw): Part 1 - Review of Available Data for Modeling

Regional Peer Review - Quebec Region

April 4-5, 2023
Mont-Joli, Quebec

Chairperson: Jean-Martin Chamberland


Atlantic herring (Clupea harengus) populations on the west coast of Newfoundland and the Lower North Shore of Quebec (NAFO Divisions 4RSw) are characterized by two spawning components. Spring spawners generally spawn in April and May, and fall herring, in August and September. Spring and fall spawning herring are considered separate stocks and are assessed separately. A first series of acoustic surveys was carried out in the fall between 1991 and 2002. A second series of surveys was initiated in the fall of 2009 and continued until 2021. These surveys target aggregations of both spring and fall spawners as they congregate near shore to feed, before beginning their migration to their wintering grounds. A summer acoustic survey was also initiated in 2019 to target fall spawner aggregations during their spawning season. The data collected from these surveys are used to calculate biomass indices and age composition for the two spawning stocks. The 2016 and 2018 assessments used a sequential population analysis (SPA) model to determine the status of the herring stocks on the west coast of Newfoundland (DFO 2016, 2018). The model used commercial fishery data and was calibrated with acoustic abundance indices. In 2020, concerns about certain aspects of the fall acoustic survey, particularly with respect to changes in catchability, led to the rejection of the SPA model as the basis for scientific advice, which resulted in the rejection of reference points and the precautionary approach (DFO 2021). During the 2020 assessment, it was determined that the review of the assessment framework was a priority. This meeting is the first of two and will be used to review the available data in order to establish a new assessment model and propose a new sampling and estimation methodology for the acoustic survey abundance index.


The objectives of this first part are:

Expected Publications

Expected Participation



Participation to CSAS peer review meetings is by invitation only.

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