Terms of Reference

Review of the Fisheries and Oceans Canada (DFO)-Industry Halibut Longline Survey Design

Regional Advisory Process – Maritimes Region

February 17, 2017
Dartmouth, Nova Scotia

Chairperson: Tana Worcester

Context

The DFO-Industry Atlantic Halibut Longline Survey provides the primary index of exploitable biomass for the Northwest Atlantic Fisheries Organization (NAFO) Divisions 3NOPs4VWX5Zc Atlantic Halibut stock assessment as well as the index of abundance for NAFO Divs. 4VWX5Z Cusk. In interim assessment years, NAFO Divs. 3NOPs4VWX5Zc Atlantic Halibut Total Allowable Catch (TAC) advice is based the q-adjusted 3-year mean of the Atlantic Halibut survey Generalized Linear Model (GLM) index. The survey is also a platform for science work including Atlantic Halibut all sizes tagging and collection of length and sex composition data, otoliths and maturity sampling.

The need to redesign the Atlantic Halibut Longline Survey was identified in the 2014 assessment Framework (DFO 2017). The survey was last modified in the mid-2000s, with the addition of stations in under-sampled areas in NAFO Subdivision 4Vn and Bay of Fundy. A preliminary investigation of the current survey design was in 2016 (Smith 2016). That review focused on the survey GLM index and recommended an alternative hook competition model. Landmark Fisheries Research has been contracted to redesign the DFO/Industry Atlantic Halibut survey for the NAFO Divs. 3NOPs4VWX5Zc stock to improve the index of abundance.

Objective

The objective of the Science Advisory Process is to evaluate:

• alternative stratified random survey design options that extend the sampling distribution of the longline survey into areas and depths that are not well represented by the current survey, and
• alternative strategies for the transition to a new survey and implications for the assessment model.

Expected Publications

• Proceedings
• Research Document

Expected Participation

• DFO Science
• DFO Fisheries and Aquaculture Management
• Industry
• Academia
• Aboriginal Communities/Organizations
• FSC License Holders

References

DFO. 2017. Proceedings of the Regional Framework Discussion on Stock Substructure of Northwest Atlantic Fisheries Organization (NAFO) Divisions 3NOPs4VWX5Zc Atlantic Halibut, Hippoglossus hippoglossus (Scotian Shelf and Southern Grand Banks); March 9-11, 2016. DFO Can. Sci. Advis. Sec. Proceed. Ser. 2017/010.

Smith, S.J. 2016. Review of the Atlantic Halibut Longline Survey Index of Exploitable Biomass. Can. Tech. Rep. Aquat. Sci. 3180: v + 56