Terms of Reference

Assessment of the Outside Stock of Pacific Spiny Dogfish (Squalus suckleyi) in British Columbia

Regional Peer Review - Pacific Region

October 17-18, 2024

Nanaimo, BC

Chairperson: Michelle Greenlaw

Context

Pacific Spiny Dogfish (Squalus suckleyi; “Dogfish”) are a wide-ranging, long-lived shark species. Tagging data suggest that in the northeast Pacific the species exists as one offshore stock that extends from Baja California to Alaska (Ketchen 1986) and two coastal stocks: one in the Strait of Georgia and one in Puget Sound (McFarlane and King, 2003; 2009). Because of this, the Dogfish population in British Columbia (BC) is assessed as two stocks: an inside stock inhabiting the Strait of Georgia and the Johnstone Strait and an outside stock inhabiting remaining coastal areas.

There is a long history of commercial fishing for Dogfish in BC dating back to the 1870s. From 1870–1916 Dogfish were pursued for oil to support the industrial lubricant and lighting industries. Peak exploitation occurred from the late 1930s until 1950 as part of a shark liver vitamin A fishery. A move to synthetic vitamin A combined with declines in Dogfish abundance ended this fishery; several smaller fisheries have occurred since. Currently, there is no directed fishery for Dogfish in BC, although they are regularly caught incidentally in groundfish fisheries.

The last stock assessment for Dogfish was completed in 2010 (Fisheries and Oceans Canada, DFO 2010, Gallucci et al. 2011, DFO 2012); however, there was “no consensus reached on a scientifically valid approach on which to base yield recommendations” (DFO 2010). Model output suggested there was insufficient contrast in the stock index data to provide productivity and scale information given the surplus production model assumptions and concluded there was no immediate conservation concern given the perceptions on stock status and lack of a directed fishery. As a result, quota for the outside stock remained at 8,160 t (DFO 2023) with catches well below this quota. It was recommended that the assessment be revisited within five years (DFO 2010).

In 2010, Dogfish were categorized as Special Concern by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) due to “low fecundity, long generation time, uncertainty regarding trends in abundance of mature individuals, reduction in size composition, and demonstrated vulnerability to overfishing” (COSEWIC 2011). While a decision by the Governor in Council to list Dogfish species under the Species at Risk Act (SARA) is still pending, COSEWIC is required to review the classification of each species at risk every 10 years (s.24 of SARA).

DFO Fisheries Management (Groundfish Management Unit; GMU) has requested DFO Science Branch provide advice regarding the outside Dogfish stock status relative to reference points that are consistent with DFO’s Precautionary Approach (DFO 2009). The assessment and advice arising from this Canadian Science Advisory Secretariat (CSAS) Regional Peer Review (RPR) meeting will be used to inform fisheries managers on stock status and to provide harvest management advice.

Objectives

The following working paper will be reviewed and provide the basis for discussion and advice on the specific objectives outlined below.

• Anderson, S.C., Huynh, Q.C., Davidson, L.N.K., King, J.R. Pacific Spiny Dogfish (Squalus suckleyi) Population Modelling for Outside Waters of British Columbia in 2024. CSAP Working Paper.

The specific objectives of this review are to:

1. Develop and assess a suite of age-structured population dynamics models for Dogfish in outside BC waters and describe the uncertainties the models are meant to address.
2. Document and discuss challenges and uncertainties regarding model assumptions and data that affect (1) reconstructing stock dynamics, (2) developing reference points consistent with the DFO Precautionary Approach (PA) Policy, and (3) evaluating status with respect to those reference points.
3. Present time series of S/S_MSY (spawning output over spawning output at maximum sustainable yield) and S/S₀ (spawning output over unfished spawning output) conditional on fitted models. Provide an upper bound on potential removal reference rates based on possible stock productivities and models.
4. Calculate probabilities of population decline relevant to COSEWIC status assessment.
5. Consider environmental conditions that may affect the stock as presented in the “Guidelines for Implementing the Fish Stocks provisions in the Fisheries Act”.
6. Recommend an appropriate path forward including recommended data collection and research, a recommended timeline to revisit the assessment, and indicators before then that may trigger an earlier than scheduled assessment. Provide a rationale if indicators and triggers cannot be identified.

Expected Publications

• Science Advisory Report
• Research Document

Expected Participation

• Fisheries and Oceans Canada (DFO) (Ecosystems and Oceans Science, Fisheries Management)
• Indigenous Organizations
• Industry
• Environmental non-government organizations

References

• COSEWIC. 2011. COSEWIC assessment and status report on the North Pacific Spiny Dogfish Squalus suckleyi in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. x + 45 pp.
• DFO. 2009. A Fishery Decision-Making Framework Incorporating the Precautionary Approach.
• DFO. 2010. Assessment of Spiny Dogfish (Squalus acanthias) in British Columbia in 2010. DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2010/057.
• DFO. 2012. Proceedings of the Pacific Region Science Advisory Process for spiny dogfish (Squalus acanthius) in British Columbia, Canada, May 17, 2010. DFO Can. Sci. Advis. Sec. Proceed. Ser. 2011/071.
• DFO. 2023. Groundfish Integrated Fisheries Management Plan 2023/24.23-2236. 337 p.
• Galluci, V., Taylor, I., King, J., McFarlane, G., McPhie, R. 2011. Spiny Dogfish (Squalus acanthias) Assessment and Catch Recommendations for 2010. DFO Can. Sci. Advis. Sec. Res. Doc. 2011/034. xii + 69 p.
• Ketchen, K.S. 1986. The spiny dogfish (Squalus acanthias) in the Northeast Pacific and a history of its utilization. Canadian Special Publication of Fisheries and Aquatic Sciences 88. 78 p.
• McFarlane, G.A., and J.R. King. 2003. Migration patterns of spiny dogfish (Squalus acanthias) in the North Pacific ocean. Fisheries Bulletin 10: 358-367.
• McFarlane, G.A. and J.R. King. 2009. [Movement patterns of spiny dogfish within the Strait of Georgia]. Pages 77–87 in V. F. Gallucci, G. A. McFarlane, and G. G. Bargmann, editors. Biology and management of spiny dogfish sharks. American Fisheries Society, Bethesda, Maryland.