Terms of Reference

Stock Assessment with Catch Projections for 4X5Y Haddock

Regional Peer Review – Maritimes Region

November 28-29, 2016
St. Andrews, New Brunswick

Chairperson: Kirsten Clark

Context

Haddock (Melanogrammus aeglefinus) are found on both sides of the North Atlantic. In the western Atlantic, they occur from southwest Greenland to Cape Hatteras. A major stock exists in the southern Scotian Shelf and Bay of Fundy area. The status of 4X5Y Haddock was last assessed in January 2012 (DFO 2012). Given model uncertainties, a framework review was recommended. An initial science review meeting held in October 2014 at Dartmouth, Nova Scotia, reviewed results of updated analyses on stock structure, spatial and temporal patterns in distribution, bycatch, biological attributes, and revisions/updates to data inputs for stock assessment (Stone and Hansen 2015). In addition, the ADAPT Virtual Population Analysis (VPA) software was used to evaluate the impacts of revisions and modifications to the 4X5Y haddock data inputs on estimates of age 1 recruits, age 4+ population biomass, and ages 6-9 fishing mortality. A second science review meeting held in April 2016 reviewed the methodologies developed for estimating current stock status, fishery reference points, forecasting methodology for providing advice, guidance on inter-framework review activities. A VPA model with natural mortality (M) at ages 10 and older fixed at 0.3, 0.6, and 0.9 for three 5-year time blocks (2000-2004, 2005-2009, and 2010-2014 respectively), was accepted as the new framework model for the 4X5Y haddock stock assessment.  It was agreed that fishing mortality removal reference point (F_ref) of 0.25 is appropriate when the stock is in the healthy zone and an F of 0.15 is appropriate when the stock is in the cautious zone.  Given that the poor stock recruit relationship precludes the calculation of an appropriate Bmsy, a more conservative Brecover of 19,700 mt was recommended as B_lim for 4X5Y haddock (DFO In prep.^{Footnote 1}; Wang et al. In prep.^{Footnote 2}).

In support of the 2017-2018 fishery for 4X5Y Haddock, DFO Maritimes Fisheries and Aquaculture Management Branch has asked DFO Maritimes Science for an assessment of resource status and the consequences of various harvest levels to inform management measures and recommendations.

Objectives

The objectives of this regional peer review process are to:

• Evaluate biological and fishery information on 4X5Y Haddock stock status and characterize the uncertainty of the results.  Specifically, provide information on distribution, biomass estimates, length and age composition, condition, highlighting trends over the long-term (length of assessment) and most recent period (5 years).
• Evaluate the current status of the stock relative to the adopted reference points.
• Evaluate the consequences of different harvest levels during the 2017/18 fishery on stock abundance and fishing mortality. Where possible, provide the following information:
• For a range of total catch values, estimate the risk that fishing mortality rate (F) would exceed the reference level for when the stock is in the healthy zone (F_ref=0.25) and the recommended F for when the stock is in the cautious zone (F=0.15) in 2017 and 2018.  Include a table showing the catches corresponding to low (25%), neutral (50%), and high (75%) probability that F would exceed F=0.25 and F=0.15.
• For a range of total catch values in 2017 and 2018, estimate the probability that spawning biomass at the beginning of year 2018 and 2019 would remain stable or not increase by 10% from the previous year’s level.
• Sensitivity analysis on the estimate of probability that the fishing mortality rate would exceed F=0.25 and F=0.15 in 2017/18 and the expected spawning biomass change under constant Total Allowable Catch.

Expected Publications

• Proceedings
• Research Document
• Science Advisory Report

Participation

• Fisheries and Oceans Canada (DFO) Science
• DFO Resource Management
• DFO Policy & Economics 
• Provinces of Nova Scotia and New Brunswick
• Academics
• Aboriginal communities/organizations
• Fishing Industry
• Other invited experts

References

DFO, 2012. Assessment of the Status of 4X5Y Haddock in 2011. DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2012/023.

Stone, H.H., and S.C. Hansen. 2015. 4X5Y Haddock 2014 Framework Assessment: Data Inputs and Exploratory Modelling. DFO Can. Sci. Advis. Sec. Res. Doc. 2015/022.