Language selection


Terms of Reference

Recovery Potential Assessment for American Plaice (Maritime Designatable Unit)

Zonal Advisory Process - Gulf, Maritimes, Quebec

March 24-25, 2011
Moncton, New-Brunswick

Chairperson: TBD


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 designatable 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.

COSEWIC has designated the American Plaice Maritime DU (April 2009) as “Threatened”. This species is not currently listed under the Species at Risk Act (SARA).

In support of a listing recommendation for this American Plaice DU 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 this American Plaice DU.


Assess current/recent species/American Plaice status
  1. Evaluate present American Plaice status for abundance (i.e., numbers and biomass focusing on matures) and range and number of populations for the DU.
  2. Evaluate recent species trajectory for abundance (i.e., numbers and biomass focusing on matures) and range and number of populations for the DU.
  3. Estimate, to the extent that information allows, the current or recent life-history parameters for American Plaice (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) and based on the limit reference points, where available, developed under the Precautionary Approach Framework.
  5. Project expected American Plaice population trajectories over 48 years (the maximum three-generation timeframe for this species in eastern Canada), which represents at least three generations for all populations, and trajectories over time to the recovery target (if possible to achieve), given current American Plaice population dynamics parameters and associated uncertainties using DFO guidelines on long-term projections (Shelton et al. 2007). See Annex 1 for details.
  6. Evaluate residence requirements for the species, if any.
Assess the Habitat Use of American Plaice
  1. Provide functional descriptions (as defined in DFO 2007b) of the properties of the aquatic habitat that American Plaice needs for successful completion of all life-history stages.
  2. Provide information on the spatial extent of the areas in American Plaice’s range that are likely to have these habitat properties.
  3. 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.
  4. Quantify how the biological function(s) that specific habitat feature(s) provide to the species varies with the state or amount of the habitat, including carrying capacity limits, if any.
  5. Quantify the presence and extent of spatial configuration constraints, if any, such as connectivity, barriers to access, etc.
  6. Provide advice on how much habitat of various qualities / properties exists at present.
  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 for abundance and range and number of populations.
  8. Provide advice on feasibility of restoring habitat to higher values, if supply may not meet demand by the time recovery targets would be reached, in the context of all available options for achieving recovery targets for population size and range.
  9. Provide advice on risks associated with habitat “allocation” decisions, if any options would be available at the time when specific areas are designated as Critical Habitat.
  10. Provide advice on the extent to which various threats can alter the quality and/or quantity of habitat that is available.
Scope for Management to Facilitate Recovery of American Plaice
  1. Assess the probability that the recovery targets (see Annex 1) can be achieved under current rates of American Plaice population dynamics parameters, and how that probability would vary with different mortality (especially lower) parameters.
  2. Quantify to the extent possible the magnitude of each major potential source of mortality identified in the pre-COSEWIC assessment, the COSEWIC Status Report, information from DFO sectors, and other sources.
  3. 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.
  4. Assess to the extent possible the magnitude by which current threats to habitats have reduced habitat quantity and quality.
Scenarios for Mitigation and Alternative to Activities
  1. 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 18 and 20).
  2. 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 18 and 20).
  3. Using input from all DFO sectors and other sources as appropriate, develop an inventory of activities that could increase the survivorship parameters (Steps 3 and 17).
  4. Estimate, to the extent possible, the reduction in mortality rate expected by each of the mitigation measures in step 21 or alternatives in step 22 and the increase in survivorship associated with each measure in step 23.
  5. Project expected population trajectory (and uncertainties) over 48 years, which represents at least three generations for the species in eastern Canada, and to the time of reaching recovery targets when recovery is feasible; given mortality rates associated with specific scenarios identified for exploration (see Annex 1). Include scenarios which provide as high a probability of survivorship and recovery as possible for biologically realistic parameter values.
  6. Recommend parameter values for 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
  1. Evaluate maximum human-induced mortality which the species can sustain and not jeopardize survival or recovery of the species.

Expected Publications


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


COSEWIC. 2009. COSEWIC assessment and status report on the American Plaice Hippoglossoides platessoides, Maritime population, Newfoundland and Labrador population and Arctic population, in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. x + 74 pp.

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.

Annex 1. Elements of Discussion for Projection Scenarios
(3 pages; 122 KB)

Avis d’accessibilité

Ce document est disponible en format PDF. Si le document suivant ne vous est pas accessible, veuillez communiquer avec le Secrétariat pour l’obtenir sous une autre forme (par exemple un imprimé ordinaire, en gros caractères, en braille ou un document audio).


Participation to CSAS peer review meetings is by invitation only.

Date modified: