Terms of Reference

Atlantic Bluefin Tuna (Thunnus thynnus) Recovery Potential Assessment

Zonal Advisory Process - Maritimes, Newfoundland & Labrador, Gulf, Quebec

13-15 July, 2011
St. Andrews, New Brunswick

Chairpersons: Lei Harris and Julie Porter

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, 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 recovery planning.

In support of listing recommendations for Atlantic Bluefin Tuna by the Minister, DFO Science has been asked to undertake an RPA, based on the National Frameworks (DFO 2007a and b). The advice in the RPA may be used to inform both scientific and socio-economic elements of the listing decision, as well as development of a recovery strategy and action plan, and to support decision-making with regards to the issuance of permits, agreements and related conditions, as per section 73, 74, 75, 77 and 78 of SARA. The advice generated via this process will also update and/or consolidate any existing advice regarding Atlantic Bluefin Tuna (Thunnus thynnus).

Objectives

• To assess the current status of the [species/population/DU].
• To the extent possible with the information available, and taking account of uncertainties:

Assess Species Status and Rrends in Atlantic Canadian Waters

1. Evaluate present Bluefin Tuna status for abundance and range and number of populations.
2. Evaluate recent species trajectory for abundance (i.e., numbers and biomass focusing on matures) and range and number of populations.
3. Estimate, to the extent that information allows, the current or recent life-history parameters for Atlantic Bluefin Tuna (total mortality, natural mortality, fecundity, maturity, recruitment, etc.) or reasonable surrogates; and associated uncertainties for all parameters.
4. Estimate expected population and distribution targets for recovery, according to DFO guidelines (DFO 2005).
5. Project expected Atlantic Bluefin Tuna population trajectories over three generations (or other biologically reasonable time), and trajectories over time to the recovery target (if possible to achieve), given current Atlantic Bluefin Tuna population dynamics parameters and associated uncertainties using DFO guidelines on long-term projections (Shelton et al. 2007).

Assess the Habitat Use of Bluefin Tunain Atlantic Canadian Waters

6. Evaluate residence requirements for the species, if any
7. Provide functional descriptions (as defined in DFO 2007b) of the properties of the aquatic habitat that Bluefin Tuna needs for successful completion of all life-history stages.
8. Provide information on the spatial extent of the areas in Bluefin Tuna’s range in Canada that are likely to have these habitat properties.
9. Recommend research or analysis activities that are necessary in order to complete these habitat-use Terms of Reference if current information is complete.
10. Identify the activities most likely to threaten the habitat properties that give the sites their value, and provide information on the extent and consequences of these activities.
11. Quantify to the extent possible the likelihood that the current quantity and quality of habitat is sufficient to allow population increase, and would be sufficient to support a population that has reached its recovery targets.
12. Assess to the extent possible the magnitude by which current threats to habitats have reduced habitat quantity and quality.

Scope for Management to Facilitate Recovery of Bluefin Tuna in Atlantic Canadian Waters

13. Quantify to the extent possible the magnitude of each major potential source of human-induced mortality identified in the pre-COSEWIC assessment, the COSEWIC Status Report (COSEWIC 2011), information from DFO sectors, and other sources.
14. Assess the probability that the recovery targets can be achieved under current rates of Atlantic Bluefin Tuna population dynamics parameters, and how that probability would vary with different mortality (especially lower) and productivity (especially higher) parameters.

Scenarios for Mitigation and Alternative to Activities

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 (Steps 3 and 15).
18. Estimate, to the extent possible, the reduction in mortality rate expected by each of the mitigation measures in step 15 or alternatives in step 16 and the increase in productivity or survivorship associated with each measure in step 17.
19. Project expected population trajectory (and uncertainties) over three generations (or other biologically reasonable time), and to the time of reaching recovery targets when recovery is feasible; given mortality rates and productivities associated with specific scenarios identified for exploration (as above). Include scenarios which provide as high a probability of survivorship and recovery as possible for biologically realistic parameter values.
20. Recommend parameter values for population productivity and starting mortality rates, and where necessary, specialized features of population models that would be required to allow exploration of additional scenarios as part of the assessment of economic, social, and cultural impacts of listing the species.

Allowable Harm Assessment

21. Evaluate maximum human-induced mortality which the species can sustain and not jeopardize survival or recovery of the species.

Expected Publications

• CSAS Science Advisory Reports
• CSAS Proceedings of meeting
• CSAS Research Document(s)

Participation

DFO Science, Ecosystems and Fisheries Management, Oceans, Habitat and Species at Risk, Policy and Economics, Aboriginal Communities, Parks Canada, Provinces, External Reviewers, Industry, Non-governmental organizations and Other Stakeholders will be invited to participate in this meeting.

References

COSEWIC. 2011 (in prep). COSEWIC Status Report on Atlantic Bluefin Tuna Thunnus thynnus. Committee on the Status of Endangered Wildlife in Canada. Ottawa.

DFO. 2005. A framework for developing science advice on recovery targets for aquatic species in the context of the Species at Risk Act. DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2005/054.

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.