Terms of Reference

Review of candidate stock assessment frameworks for the Northwest Atlantic Fisheries Organization Subarea 0+1 (Offshore) Greenland Halibut stock

Regional Peer Review – Ontario & Prairie Region

December 12-15, 2022
Winnipeg, MB and Virtual Meeting

Chairperson: Mary Thiess

Context

Fisheries and Oceans Canada (DFO) Science and the Greenland Institute of Natural Resources conduct multi-species bottom trawl surveys in Northwest Atlantic Fisheries Organization (NAFO) Subareas 0 and 1 to support assessment of the Subarea 0+1 (offshore) Greenland Halibut stock. The vessel and gear (RV Paamiut, Alfredo trawl) used for the surveys during 1999-2017 was retired in 2018 without opportunity to conduct paired trawling experiments with an interim or replacement vessel. An interim vessel and the Alfredo trawl were used in 2019 and a new long-term vessel (RV Tarajoq) and new gear (Bacalao trawl) will be used in 2022 and beyond. Typically, the ability to assess time series data relies on an assumption that consistent methods and effort are used over time to ensure inter-year comparability (i.e., any differences in gear or sampling effort are known or can be estimated). Survey time series are typically standardized through periods of change in data collection methods by conducting paired trawling experiments.

Given the absence of these experiments, DFO Fisheries Management has requested DFO Science to explore analytical method(s) and/or frameworks for the Subarea 0+1 (offshore) stock assessment that could incorporate data collected by multiple vessels and gears, including fishery-independent surveys and commercial fishery data. This review aims to support the NAFO Scientific Council’s assessment of this stock and industry led Marine Stewardship Council certification process.

Objectives

The main objectives of the Canadian Science Advisory Secretariat (CSAS) process is to identify potential analytical methods and/or frameworks that could be used to improve the Subarea 0+1 (offshore) Greenland Halibut stock assessment. Specifically, the review will include:

1. Identify factors contributing to differences in catchability of Greenland Halibut and other fish and invertebrate species; and,
2. Examine analytical methods and/or frameworks that could allow integration and/or comparison of data collected by different vessels and gear configurations.

Expected Publications

• Science Advisory Report
• Proceedings
• Research Documents

Expected Participation

• Fisheries and Oceans Canada (DFO) (Ecosystems and Oceans Science and Fisheries Management sectors)
• Academia
• Industry
• Other invited experts