Terms of Reference

Northwest Atlantic Spiny Dogfish Framework Part 1: Review of Data Inputs

Regional Advisory Process – Maritimes Region

September 19-20, 2017
Dartmouth, Nova Scotia

Chairperson: Kent Smedbol

Context

The Northwest Atlantic Spiny Dogfish is a transboundary resource with significant catches in Canada and the United States (USA). Although a joint Canada-US Transboundary Resources Assessment Committee (TRAC) assessment was held in early 2010, consensus on an assessment model was not reached. Both the US and Canada have continued to assess the stock independently since 2010.

The last DFO framework review and assessment of Northwest Atlantic Spiny Dogfish occurred in January and May 2014 using data up to 2010 (Fowler et al. 2015).  The accepted model was a forward-projecting stage-based, spatially explicit population dynamics model with two time steps. Efforts to incorporate more recent data into the framework model have not been successful. This is likely due to substantial changes in our understanding of dogfish catchability owing to recent research on day/night patterns as well as the deployment of a new survey vessel in the US in 2009. Both would affect the main abundance index used to assess the population. 

Fisheries Management has requested annual updates for Northwest Atlantic Spiny Dogfish. DFO Science has determined that a new framework assessment is required to meet this request.

Objectives

The objectives of the Regional Advisory Process are to:

1. Describe the USA and Canadian data used in an assessment.
   • Commercial and recreational fishery characteristics (catch composition, discards, discard mortality)
   • Description of the survey data used to develop indices of abundance
   • Stock definition
2. Evaluate factors affecting dogfish catchability, including their implications for abundance estimation.
   • diel patterns
   • changes to survey methodology and vessel; focused on the USA spring survey (sampling of outer slope strata, catchability at length). 
3. Review proposed methods to standardize the abundance index from the US spring survey for input into an assessment model.

Expected Publications

• Proceedings
• Research Document

Expected Participation

• DFO Science
• DFO Fisheries and Aquaculture Management
• Provincial representatives
• Aboriginal Communities/Organizations
• Industry Representatives
• Academia
• Invited external experts
• Environmental Non-Governmental Organizations

Reference

Fowler, G.M., and Campana, S.E. 2015. Framework Assessment and 2013 Update Using a Stage-based Population Model for Spiny Dogfish (Squalus acanthias) in the Northwest Atlantic. DFO Can. Sci. Advis. Sec. Res. Doc. 2015/065.