Terms of Reference

Redstripe Rockfish (Sebastes proriger) stock assessment for British Columbia in 2018

Regional Peer Review Process – Pacific Region

June 13-14, 2018
Nanaimo, BC

Chairperson: Greg Workman

Context

Redstripe Rockfish (Sebastes proriger) ranges from the southeastern Bering Sea to Baja California and is abundant between southeast Alaska and central Oregon.  Prior to 1977, there were few catch restrictions for British Columbia (BC) rockfish.  Since then, groundfish management plans have become increasingly complex for targeted rockfish species; introducing quotas for Redstripe Rockfish in 1993.  Today, Redstripe Rockfish is a quota species caught primarily by the trawl fishery, with minor amounts caught in the groundfish hook and line fisheries.  Redstripe Rockfish is predominately taken by bottom and mid water trawl gear in BC waters.  This species is also captured in the mid-water Pacific Hake fishery.

In the 1990’s, Fisheries and Oceans Canada (DFO) Science assessed Redstripe Rockfish annually as part of a multi-species slope rockfish complex, where the species showed periods of decline.  These assessments did not evaluate stock status in relation to reference points.  However, an attempt was made to fully assess this species in 2011, as part of a simultaneous stock assessment of five rockfish species (Taylor et al. 2011, unpublished document^{Footnote 1}).

In the absence of updated science advice, there is uncertainty about the risks posed to the BC stock by current levels of catch. There is also a requirement to estimate stock status relative to reference points that are consistent with the DFO’s Fishery Decision-Making Framework Incorporating the Precautionary Approach (DFO 2009). There are no published studies that have examined the genetic population structure of Redstripe Rockfish in northeast Pacific waters, and to date, this species has been treated as one coastwide stock in BC.

DFO Fisheries Management has requested that DFO Science provide advice regarding the assessment of the BC Redstripe Rockfish stock relative to reference points that are consistent with the DFO’s Precautionary Approach, including the implications of various harvest strategies on expected stock status. The advice arising from this Canadian Science Advisory Secretariat (CSAS) Regional Peer Review (RPR) will be used to inform fisheries management decisions to establish catch levels for the species.  This work may also inform and supplement decisions external to DFO, including Marine Stewardship Council certification of the Pacific Hake fishery.

Objective

The following working paper will be reviewed and provide the basis for discussion and advice on the specific objectives outlined below:
Redstripe Rockfish (Sebastes proriger) stock assessment for British Columbia in 2018. Paul J. Starr and Rowan Haigh. 2018. CSAP Working Paper 2015GRF08
The specific objectives of this review are to:

1. Recommend reference points consistent with the DFO Precautionary Approach, including the biological considerations and rationale used to make such a determination.  Evaluate the current status of Redstripe Rockfish relative to the recommended reference points.
2. Assess the current status of Redstripe Rockfish in BC waters, relative to the recommended reference points. If necessary, provide evidence to support the separation of this species into spatially distinct stocks, and if required, provide advice on the status of these stocks.
3. Using probabilistic decision tables, evaluate the consequences of a range of constant catch harvest policies to projected biomass relative to the reference points and additional stock metrics, including projected biomass relative to current biomass.  If the data are insufficient to quantitatively evaluate BC Redstripe Rockfish in terms of PA reference points and decision tables, summarise what is known about the status of this species, and the implications for harvest advice.
4. Describe sources of uncertainty related to the model (e.g. model parameter estimates, assumptions regarding catch, productivity, carrying capacity and population status).
5. Recommend an appropriate interval between formal stock assessments, indicators used to characterize stock status in the intervening years, and/or triggers of an earlier than scheduled assessment.  Provide a rationale if indicators and triggers cannot be identified.

Expected Publications

• Science Advisory Report
• Proceedings
• Research Document

Expected Participation

• Fisheries and Oceans Canada (DFO) (Science and Fisheries Management)
• Commercial and Recreational Fishing Representatives
• Environmental Non-government Organizations
• First Nations
• Province of BC
• USA Government Agencies (NOAA, Alaska Fish & Game)

References

DFO 2009. A Fishery Decision-Making Framework Incorporating the Precautionary Approach