Terms of Reference

Recovery Potential Assessment for Atlantic Salmon (Nova Scotia Southern Upland Designatable Unit)

Regional Peer Review – Maritimes Region

May 22-25, 2012
Dartmouth, Nova Scotia

Chairperson: Tana Worcester

Context

When the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) designates aquatic species as threatened or endangered, Fisheries and Oceans Canada (DFO), as the responsible jurisdiction under the Species at Risk Act (SARA), is required to undertake a number of actions. Many of these actions require scientific information on the current status of the species, population or designable unit (DU), threats to its survival and recovery, habitat needs, and the feasibility of its recovery. Formulation of this scientific advice has typically been developed through a Recovery Potential Assessment (RPA) that is conducted shortly after the COSEWIC assessment. This timing allows for the consideration of peer-reviewed scientific analyses into SARA processes including listing decisions and recovery planning.

The Nova Scotia Southern Upland DU of Atlantic salmon was designated as Endangered by COSEWIC in November 2010. This DU extends from northeastern mainland Nova Scotia (approximately 45°21’N, 61°28’W) southward and into the Bay of Fundy to Cape Split (approximately 45°20’N, 64°30’W). Both mtDNA and microsatellite data suggest that gene flow between the Nova Scotia Southern Upland DU and the neighbouring Eastern Cape Breton and inner Bay of Fundy DUs is minimal. Many rivers in this DU have freshwater habitat with relatively low pH. They also have lower proportions of multi-sea winter (MSW) fish than their northern neighbours. Southerly populations in this DU also have some of the youngest smolt ages reported in Canada. This DU also has an extensive history of stocking, including recent efforts to slow the decline of a few of the severely depressed populations in the DU. DFO Science has been asked to undertake an RPA for the Nova Scotia Southern Upland DU, based on the National Framework (DFO 2007a).

Objectives

The overarching objective of this meeting is to determine the recovery potential of the Nova Scotia Southern Upland DU of Atlantic salmon. Specifically, to the extent possible with the information available, and taking account of uncertainties:

Status and Trends

1. Evaluate present abundance and range.
2. Evaluate recent trajectory for species abundance and range.
3. Estimate, to the extent that information allows, the current or recent life-history parameters (total mortality, natural mortality, fecundity, maturity, recruitment, etc.) or reasonable surrogates; and associated uncertainties for all parameters.

Habitat Considerations

4. Provide functional descriptions (as defined in DFO 2007b) of the properties of the aquatic habitat that the Nova Scotia Southern Upland DU of Atlantic salmon needs for successful completion of all life-history stages.
5. Provide information on the spatial extent of the areas in the Nova Scotia Southern Upland DU of Atlantic salmon range that are likely to have these properties.
6. Quantify the presence and extent of spatial configuration constraints, if any, such as connectivity, barriers to access, etc.
7. Provide advice on the degree to which supply of suitable habitat meets the demands of the species both at present, and when the species reaches biologically based recovery targets.
8. Provide advice on any tradeoffs (i.e., pros and cons) associated with habitat “allocation” options, if any options would be available at the time when specific areas may be designated as Critical Habitat.
9. Evaluate residence requirements for the species, if any.
10. Recommend research or analysis activities that are necessary in order to complete these habitat-use Terms of Reference if current information is incomplete.

Recovery Targets

11. Estimate expected abundance and distribution targets for recovery, according to DFO guidelines (DFO 2011).

Threats

12. Quantify to the extent possible the magnitude of each major potential source of mortality identified in the COSEWIC Status Report (COSEWIC 2010), information from DFO sectors, and other sources including:
    • Poor marine survival,
    • Changes in climate,
    • Fishing (bycatch, subsistence, recreational, and illegal),
    • Dams and obstructions in freshwater,
    • Agriculture, forestry,
    • Urbanization,
    • Acidification,
    • Hatcheries,
    • Aquaculture, and
    • Invasive species.
13. Identify the activities most likely to result in threats to the functional properties of the habitat of the Nova Scotia Southern Upland DU of Atlantic salmon, and provide information on the extent and consequences of these activities within the species’ range.
14. Assess to the extent possible how threats to habitats identified in the COSEWIC Status Report (COSEWIC 2011) have reduced habitat quantity and quality to date, if at all.

Mitigation and Alternatives

15. Using input from all DFO sectors and other sources as appropriate, develop an inventory of all feasible measures to minimize/mitigate the impacts of activities that are threats to the species and its habitat (Steps 12 and 13).
16. Using input from all DFO sectors and other sources as appropriate, develop an inventory of all reasonable alternatives to the activities that are threats to the species and its habitat (Steps 12 and 13).
17. Using input from all DFO sectors and other sources as appropriate, develop an inventory of activities that could increase the productivity or survivorship parameters (Step 3).
18. Provide advice on feasibility of restoring habitat to higher values, if supply may not meet demand by the time recovery targets would be reached.
19. Estimate, to the extent possible, the expected impact on abundance and distribution objectives from identified mitigation measures (Step 15), alternatives (Step 16), or recovery activities (Steps 17 and 18).

Assessment of Recovery Potential

20. Given current dynamics parameters and associated uncertainties, project expected population trajectories over three generations (or other biologically reasonable time), and trajectories over time to the recovery objectives, using DFO guidelines on long-term projections (Shelton et al. 2007).
21. Given alternative mortality rates and productivities associated with specific scenarios identified in Step 17, project expected population trajectory over three generations (or other biologically reasonable time), and to the time of reaching recovery objectives.
22. Assess the probability that the recovery objectives can be achieved under current rates of population dynamics parameters, and how that probability would vary with different mortality (especially lower) and productivity (especially higher) parameters.

Expected Publications

• CSAS Science Advisory Report
• CSAS Proceedings
• CSAS Research Document

Participation

• DFO Science
• DFO Fisheries and Aquaculture Management, Oceans and Habitat Management, Policy and Economics, and the Species at Risk Management Division
• Parks Canada
• Province of Nova Scotia
• Aboriginal Communities
• Industry
• Non-governmental organizations
• External Reviewers
• Other Stakeholders

References

COSEWIC. 2010. COSEWIC assessment and status report on the Atlantic salmon Salmo salar (Nunavik population, Labrador population, Northeast Newfoundland population, South Newfoundland population, Northwest Newfoundland population, Quebec Eastern North Shore population, Quebec Western North Shore population, Anticosti Island population, Inner St. Lawrence population, Lake Ontario population, Gaspé-Southern Gulf of St. Lawrence population, Eastern Cape Breton population, Nova Scotia Southern Upland population, Inner Bay of Fundy population, Outer Bay of Fundy population) in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa.

DFO. 2011. A Complement to the 2005 Framework for Developing Science Advice on Recovery Targets in the Context of the Species At Risk Act. DFO. Can. Sci. Advis. Sec. Sci. Advis. Rep. 2010/061.

DFO. 2007a. Revised Protocol for Conducting Recovery Potential Assessments. DFO. Can. Sci. Advis. Sec. Sci. Advis. Rep. 2007/039.

DFO. 2007b. Documenting habitat use of species at risk and quantifying habitat quality. DFO. Can. Sci. Advis. Sec. Sci. Advis. Rep. 2007/038.

Shelton, P.A., B. Best, A. Cass, C. Cyr, D. Duplisea, J. Gibson, M. Hammill, S. Khwaja, M. Koops, K. Martin, B. O’Boyle, J. Rice, A. Sinclair, K. Smedbol, D. Swain, L. Velez-Espino, and C. Wood. 2007. Assessing recovery potential: long-term projections and their implications for socio-economic analysis. DFO. Can. Sci. Advis. Sec. Res. Doc. 2007/045.