Terms of Reference

Review of risks and benefits of adult captive-reared supplementation activities to fitness of wild Atlantic Salmon

Regional Peer Review – Gulf Region

December 14-16, 2015
Moncton, New Brunswick

Chairpersons: Wayne Fairchild and Marc Lanteigne (DFO Gulf)

Context

In response to low returns of salmon to the Miramichi River in 2014, particularly to the Northwest Miramichi River (which attained 22% of the conservation requirement; DFO 2015), non-government organisations in New Brunswick proposed a stock supplementation program consisting of the capture of wild Atlantic salmon smolts, rearing these in captivity to the adult stage, and subsequently release of these adult captive-reared fish back to the river as adults to spawn. This revised stock supplementation activity is intended to circumvent the presently low marine return rates of Atlantic salmon to the Miramichi River. The proposed intervention is an important change in supplementation programs and activities for the Miramichi River and for Gulf Region overall which to date have used returning adult salmon as broodstock, spawning in the hatchery, and stocking of juveniles of various stages into freshwater.

The proposed supplementation activity is not considered to be without risks to long-term fitness of wild Atlantic salmon populations nor are the benefits of this activity to meeting conservation objectives of Atlantic salmon easily evaluated (Waples 1999). Rearing of wild captured Atlantic salmon smolts to adult stages in captivity, and release of captive reared adults to targeted rivers to spawn, has been undertaken by DFO Maritimes Region as one of the recovery actions for endangered populations of salmon in the Inner Bay of Fundy and in the Saint John River (NB). Evaluation of the effectiveness of the captive-reared program is ongoing but no results have been reported to date.

As a precedent setting activity for supplementation of Atlantic salmon populations in Gulf Region, a formal science review to provide advice to DFO Fisheries and Aquaculture Management, the sector responsible for issuing the permits for such an activity, will be undertaken. The advice provided will be relevant in the context of the proposed captive-reared adult supplementation activity for the Miramichi River. The advice could be used to address potential requests by other groups in other watersheds to undertake similar supplementation programs in rivers in which Atlantic salmon status is below conservation requirements or not achieving other management objectives. The science advice could apply across DFO regions (Gulf, Maritimes, Newfoundland and Labrador). The science review would not consider the risks of juvenile (fry, parr, smolt) supplementation programs currently undertaken in Gulf Region by NGO groups, the provinces of Nova Scotia and Prince Edward Island, as these are approved as per the hatchery divestiture agreement conditions.

Objectives

The science peer review meeting will formulate advice by considering the following points:

1. description of proposed captive-reared adult stock supplementation program for Miramichi
   • program objectives
   • program activities including number of smolts collected, anticipated survival rates, growth characteristics, disease considerations
   • expected outcomes
   • proposed monitoring program of captive reared adult behaviour and interactions with wild Atlantic salmon
   • proposed monitoring program to assess spawning success, juvenile production, smolt production, adult production resulting from captive reared adult salmon spawners
2. overview of ongoing captive adult rearing programs in Maritimes Region for recovery of endangered populations including:
   • defined program objectives and timelines
   • survival rates, growth rates, life cycle considerations (years to obtain mature adults, adult characteristics compared to wild salmon)
   • ongoing monitoring activities and program evaluation results
3. review of status and characteristics of the Atlantic salmon population of the Miramichi River:
   • stock status of Atlantic salmon in the Miramichi including adult salmon abundance, indices of freshwater production, indices of marine survival
   • biological characteristics of Atlantic salmon in the Miramichi River (sex ratio of smolts, sea age at maturity of adults, fecundity and egg size considerations)
   • genetic characteristics of Miramichi River salmon
4. review of risks of adult captive reared supplementation programs to fitness of wild Atlantic salmon populations considering:
   • genetics: short-term and long-term fitness consequences
   • ecological considerations of wild versus cultured fish interactions including disease, competition, predation, compensatory mortality
   • criteria and metrics for assessing risk of captive-reared adult supplementation program
   • risk assessment of captive-reared adult supplementation activity to wild Atlantic salmon of the Miramichi River
   • conditions under which captive-reared adult supplementation programs would be considered negligible risk to fitness of wild Atlantic salmon
5. recommended monitoring programs to assess interactions of captive-reared adult salmon with wild salmon and to assess success to meeting supplementation program objectives.

Expected Publications

• Science Advisory Report
• Proceedings
• Research Documents

Participation

• Fisheries and Oceans Canada (DFO) (Ecosystems and Oceans Science, Ecosystems and Fisheries Management)
• Provincial governments of the Maritime Provinces
• Academia
• Aboriginal organizations
• Non-government organizations

References

DFO. 2015. Update of stock status of Atlantic Salmon (Salmo salar) in DFO Gulf Region (New Brunswick Salmon Fishing Areas 15 and 16) for 2014. DFO Can. Sci. Advis. Sec. Sci. Resp. 2015/008.

Waples, R.S. 1999. Dispelling some myths about hatcheries. Fisheries 24: 12–21.