Terms of Reference

Recovery Potential Assessment (RPA) for Atlantic Mud Piddock (Barnea truncate)

Maritimes Region, Science Advisory Process Meeting

30 September and October 1, 2010, Bedford Institute of Oceanography

Chairperson: Tom Sephton

Context

When the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) designates aquatic species as threatened or endangered, 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 decisions.

The Atlantic mud paddock, a small intertidal marine bivalve, is restricted to a single population in the Minas Basin, Nova Scotia. Although this species is adapted to boring into hard clay and soft rock, in Canada it is entirely dependent on a single geological formation, the red-mudstone facies within the basin. The total available habitat for this species is < 0.6 km². It was designated by COSEWIC as Threatened in November 2009 due to its small area of occupancy. 

DFO Science has been asked to undertake an RPA, based on the National Framework (DFO 2007a). The advice generated via this process will also update any existing advice regarding this species.

Objectives

The overarching objective of this meeting is to determine the recovery potential of Atlantic mud piddock. 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 Atlantic mud piddockneeds for successful completion of all life-history stages.
5. Provide information on the spatial extent of the areas in the Atlantic mud piddock’s 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 objectives.
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, 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 Objectives

11. Estimate expected abundance and distribution objectives for recovery, according to DFO guidelines (DFO 2005).

Threats

12. Quantify to the extent possible the magnitude of each major potential source of mortality identified in the COSEWIC Status Report, information from DFO sectors, and other sources.
13. Identify the activities most likely to result in threats to the functional properties of the habitat of Atlantic mud piddock, 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 2009) 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 potential measures that could be used to minimize/mitigate the impacts of activities identified in Steps 13 and 14.
16. Using input from all DFO sectors and other sources as appropriate, develop an inventory of potential alternatives to the activities identified in Steps 13 and 14.
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 identified in 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 16), alternatives (Step 17), or recovery activities (Steps 18 and 19).

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 dynamics parameters, and how that probability would vary with different mortality (especially lower) and productivity (especially higher) parameters.

Outputs

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 SARA Coordination Office
Aboriginal Communities
Parks Canada
Provinces of Nova Scotia and New Brunswick
External Reviewers
Industry
Non-governmental organizations
Other Stakeholders

References

COSEWIC. 2009. COSEWIC Assessment and Status Report on the Atlantic Mud Piddock (Barnea truncate) in Canada. 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.