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Recovery Strategy for the Atlantic Whitefish (Coregonus huntsmani) in Canada (Final)


2. Recovery

For Atlantic whitefish, survival and recovery have specific meanings that are clearly defined as follows:

Survival is ensuring that Atlantic whitefish continue to exist in the wild in Nova Scotia. This includes continued existence within their current known habitat, but also elsewhere in established populations. Additional populations are required for survival purposes to reduce the risk of extinction should some accidental or random event result in the extirpation of the existing population in the Petite Rivière Lakes.

Recovery requires enabling anadromy, and range extension outside the Petite Rivière lakes. Recovery also inherently requires that survival is achieved. Options for achieving anadromy include the repatriation of the anadromous run to the Tusket River, the promotion of anadromy on the Petite Rivière, or the promotion of anadromy elsewhere. Range extension also requires additional freshwater resident populations.

2.1 Recovery Feasibility

The recovery of Atlantic whitefish is both biologically and technically feasible.

2.1.1 Biological Feasibility

The underlying basis for their decline in geographic range, and the concurrent loss of anadromy of the Atlantic whitefish was most likely past human interference, particularly with migration. For the past 20 years, federal fisheries regulations have prohibited fishing of Atlantic whitefish, however before this, there was minimal protection aimed specifically at this species. Despite these factors, the species has survived. Atlantic whitefish are therefore likely to respond positively to recovery efforts aimed at mitigating and correcting past human interference, including fish passage improvements to encourage anadromy, and recent fisheries regulations that provide added protection for this species.

The Recovery Team has confidence that the Atlantic whitefish is biologically capable of survival in areas beyond its current range including estuarine and marine habitats. Atlantic whitefish can adapt to new freshwater and marine environments: they naturally colonized Minamkeak Lake and there is historical evidence of their presence in estuaries. This, along with recent field and laboratory research that indicates the species can tolerate full sea water from an early stage of development (DFO unpublished data), supports that restoration of anadromy is feasible. Atlantic whitefish can tolerate capture and removal from the wild, and transportation to facilities where they survive for several years in captivity. Atlantic whitefish can also be cultured. This species is expected to respond relatively rapidly to recovery actions given that their approximate age at first maturity is 3 years.

The biological feasibility of Atlantic whitefish recovery also depends upon their continued survival within their current environment. The Petite Rivière drainage is naturally buffered from acid rain, and the lakes receive added protection as a municipal water supply. Water quality is not considered to pose either a current or future threat to the survival of Atlantic whitefish in the Petite Rivière, provided current water management practices continue.

2.1.2 Technical Feasibility

Recovery of the species requires stability in the current population (i.e., survival), reestablishment of the anadromous form, and expansion beyond the current range. To achieve these aspects of recovery, it must be technically feasible to move Atlantic whitefish from one area to another, and to grow and reproduce the species in captivity. Wild Atlantic whitefish have been successfully moved into captive breeding facilities indicating that moving the species into areas beyond its current range is technically possible. The facilities and expertise also exist to grow Atlantic whitefish in captivity. Captive breeding techniques have been developed at the Mersey Biodiversity Facility that allows the species to be spawned and reared in abundance in captivity. It is also possible to effectively mimic the spawning practice in the wild by reconditioning wild-caught fish to spawn more than once.

Recovery is also technically feasible because the known human induced threats that impact Atlantic whitefish have the potential to be mitigated (e.g., see Allowable Activities section 2.7). These activities are also subject to regulation by federal, provincial and municipal governments. For example, more recent federal fisheries regulations offer added protection to Atlantic whitefish by providing greater flexibility to adjust seasons and gear types in fisheries directed at other species. This flexibility will benefit Atlantic whitefish by reducing their vulnerability to incidental catch and it is expected they will respond well to this added protection.

A support network to implement and adhere to recovery measures is also required for recovery to be technically feasible. Local non-government organizations and community groups, industries that operate in Atlantic whitefish habitat, as well as provincial and municipal governments support the recovery of Atlantic whitefish and are members of the Recovery Team. The Atlantic whitefish is also listed as an endangered species under the Nova Scotia Endangered Species Act. This listing should facilitate the implementation of recovery actions between federal and provincial governments.

As mentioned above with respect to the biological feasibility of recovery, the remaining population of Atlantic whitefish may have survived due to the refuge provided by the dams on the Petite Rivière. There are some concerns that restoring open migration routes on this system could actually pose a risk to recovery. The Recovery Team maintains that restoring free access to the ocean on the Petite Rivière is key to promoting anadromy which is a positive outcome both within the context of survival and recovery. Although a precautionary approach to providing fish passage is required, this approach is technically feasible. Implementation of fish passage would have to include controls to exclude undesirable species (e.g., non-native fish), security to prevent poaching, and monitoring facilities to study and respond to the movements of Atlantic whitefish, and the abundance, movements and ecological effects of the other species in this system.

2.2 Recovery Goal

The goal of the Atlantic whitefish recovery strategy is to: Achieve stability in the current population of Atlantic whitefish in Nova Scotia, reestablishment of the anadromous form, and expansion beyond its current range.

2.3 Recovery Objectives

Creating and maintaining the necessary conditions to achieve a viable population of Atlantic whitefish in Nova Scotia will be accomplished by implementing the following prioritized recovery objectives:

  • Objective 1: Conserve, protect and manage the species and its habitat.

  • Objective 2: Increase the number and range of viable populations.

  • Objective 3: Increase understanding of the species and its habitat.

  • Objective 4: Increase public involvement and acceptance.

Following each objective is a set of non-prioritized strategies that, when implemented, will contribute to the fulfillment of their corresponding objective. These strategies are designed to provide sufficient detail to facilitate the application of SARA, and to assist the next step of recovery planning, which is the development of recovery action plans.

The four recovery objectives and their respective strategies are as follows:

Objective 1: Conserve, protect and manage the species and its habitat.

Rationale:

The Atlantic whitefish in the Petite Rivière system are all that remains of this species in the wild. The survival of this species depends on the protection of remaining wild fish, and the habitat that they occupy (i.e., three semi-natural lakes in the Petite Rivièrewatershed). Conservation, protection and management of the species and its habitat will also be required in any range extension to ensure the species survival and progress towards recovery.

Strategies:
  1. Address emergent threats to survival.
    • initiate contingency planning to deal effectively with these threats, and;
    • develop and implement mitigation measures to reduce, control or eliminate emergent threats (e.g., measures to control invasion of non-indigenous species).


  2. Develop and implement mitigation measures to minimize human-induced harm to the species and its habitat.

  3. Ensure regulatory compliance.
    • enforcement of regulations to protect whitefish and their habitat;
    • report instances of non compliance, and;
    • assess adequacy of enforcement (i.e., are regulations being adequately applied to protect whitefish and their habitat, and adjust as appropriate).


  4. Develop and implement watershed and site specific habitat quality management and protection.

Objective 2: Increase the number and range of viable populations

Rationale:

In the wild, Atlantic whitefish currently exist only in the Petite Rivière. Recovery of this species must entail more than simply the survival of what remains in the Petite Rivière. The recovery of this species requires enabling anadromy, and range extension outside the Petite Rivière lakes. Recovery also inherently requires that survival is achieved. Options for achieving anadromy include the repatriation of the anadromous run to the Tusket River, promotion of anadromy on the Petite Rivière, or promotion of anadromy elsewhere. Range extension also requires additional freshwater resident populations. Any change in their current habitat could seriously threaten the survival of Atlantic whitefish (e.g., random event, accidental spill, etc.); therefore, the survival of this species also depends on the establishment of viable populations in locations beyond its current range.

Strategies:
  1. Work toward establishing viable anadromous runs. Assess the feasibility of the following options.
    • repatriation of an anadromous run to the Tusket system, and;
    • establishment of anadromous populations elsewhere including the Petite Rivière.


  2. Maintain the infrastructure and expertise to support captive rearing and re-introduction.

  3. Develop a decision support tool to direct fish releases into available and appropriate habitat (balance biological and socio-economic considerations).

  4. Plan and execute fish releases in selected watersheds and/or lakes (select donor stock - transplanted wild fish vs. captive reared) in accordance with Introduction and Transfer Guidelines.

  5. Plan and support habitat conservation, protection, and possibly restoration in areas selected for releases. In areas with sea access, this will involve protection and management measures from the location of release, and into estuarine and coastal areas.

Objective 3: Increase understanding of the species and its habitat.

Rationale:

The current state of knowledge about the basic biology and ecology of Atlantic whitefish and its habitat requirements is limited. Pressing research concerns include the lack of a quantitative population estimate for this species, the potential impacts of introduced species on the remaining wild population of Atlantic whitefish, and the paucity of basic information on habitat use and preferences by life stage. More understanding is required to support survival and recovery efforts, threat assessments, and the application of the SARA prohibitions that protect the species and its habitat (including any potential residence and/or critical habitat identified).

Strategies:
  1. Implement scheduled quantitative assessments of species status (information is required to assess threats, manage broodstock, evaluate effectiveness of actions).

  2. Develop and undertake research programs to identify habitat requirements (freshwater, estuarine and coastal), including studies to define critical habitat (see section 1.7), and to determine if the residence concept applies to Atlantic whitefish.

  3. Continue research to address knowledge gaps including, but not limited to, genetics, health (including disease and parasites), nutrition, life cycle history, behavior, and physiology.

  4. Assess the degree of risk posed by current and emergent threats.

Objective 4: Increase public involvement and acceptance.

Rationale:

Unlike many other endangered species, the Atlantic whitefish does not currently have a high level of charismatic appeal, and is not particularly well known among the general public. Increasing the level of stakeholder concern and sense of responsibility for the survival and recovery of this species is critical to ensuring the success of recovery efforts. This will be a particular challenge when considering the repatriation or introduction of this endangered species into water bodies. Communication and education are important tools for promoting recovery efforts with both stakeholders and the general public.

Strategies:
  1. Develop a general communications plan.

  2. Develop a strategy to encourage public support for survival and recovery actions.

  3. Encourage stewardship initiatives aimed at conserving, protecting and managing the species and its habitat. Involve local groups to the extent possible (e.g., Aboriginal, recreational and commercial fishers, shoreline property owners, volunteer-based and non-government organizations, industry, the community at large) that have interest in the aquatic resources in the watersheds and estuaries.

  4. Promote Recovery Team meetings as opportunity for communication and collaborations among all team members.

2.4 Performance Indicators

Measurable performance indicators will be a critical component of the recovery action plan for the Atlantic whitefish to gauge the extent to which recovery activities are successful in contributing to the stated recovery goal for the species. An ongoing assessment of the efficacy of actions undertaken within a recovery initiative as part of the action planning process will be critical to ensuring both intelligent use of resources as well as the greatest likelihood of species recovery.

2.5 Identification of Knowledge Gaps

Significant progress has been achieved since the formation of the Recovery Team in 1999 in addressing knowledge gaps of importance to recovery planning and recovery strategy implementation. Information is now available or forthcoming from current activities for the following:

  • phylogenetic status, historic and current range and status of the species;
  • genetic health of the remaining members of the species;
  • accurate field identification of living specimens using external characters;
  • genetic markers to support enforcement efforts and future assessments of species distribution;
  • captive breeding and rearing protocols;
  • life-history stage specific assessments of susceptibility to acid (rain) toxicity; thermal preferences, and salinity tolerance;
  • trophic position of Atlantic whitefish residing in lakes;
  • degree of threat to survival and recovery posed by invasive species;
  • effects of current human activities on Atlantic whitefish survival;
  • fish passage requirements around dams, and;
  • feasibility of establishing additional freshwater resident populations using seed stock reared in captivity.

Although the above acquired information will possibly improve the likelihood that the recovery actions will be successful, the adequacy of the existing information base is uncertain. Recovery of the species can only be realized through range extension into the marine realm (i.e., anadromy), and into freshwater habitat not currently occupied by the species. There is no existing information on the life history of Atlantic whitefish anywhere other than within the Petite Rivière lakes. As new information is acquired, the Recovery Team must use an adaptive management approach to ensure survival of the species within existing habitat, and to ensure the success of range expansion into the marine realm and additional freshwater sites. Knowledge gaps that must be addressed as recovery implementation continues to unfold include:

Monitoring

  • quantitative assessment of population size, age composition and age at maturity, and growth and mortality;
  • effects of current human activities on Atlantic whitefish survival, and;
  • fish passage requirements.

Captive Rearing

  • nutritional, husbandry, and space requirements to maintain Atlantic whitefish in captivity, and;
  • likelihood that domestication selection will occur within Atlantic whitefish spawned and reared in captivity.

Habitat

  • determination of specific habitat requirements as they relate to spawning, incubation, rearing and thermal refugial requirements;
  • seasonal area of occupancy of Atlantic whitefish;
  • identification and mapping of residences and critical habitat, and;
  • assessment of habitat suitability within candidate stocking sites.

For details on specific activities that target the key knowledge gaps in the habitat requirements and identification of critical habitat for Atlantic whitefish view the "Schedule of Studies" to identify critical habitat in Appendix II.

2.6 Development of Action Plans

Recovery action plans are the documents that lay out how recovery strategies are to be implemented. Action plans take recommendations from the recovery strategy, either individually or collectively, and chart out who needs to be involved and to what extent in carrying out the proposed activities.

Following the approval of this recovery strategy under SARA and posting on the Public Registry, a recovery Action Plan for the Atlantic whitefish will be developed within two years. In the interim, many of the strategies in this document can be acted on and therefore, recovery implementation will be an ongoing activity that can occur in the absence of any formal action plan. Furthermore, the Strategy recognizes the need for adaptive management; as new information becomes available, the actions for recovery may be modified.

2.7 Activities Permitted by the Recovery Strategy

As set out in subsection 83(4) of the Species at Risk Act, a person can engage in an otherwise prohibited activity if the activity is permitted by a recovery strategy and the person is authorized under an Act of Parliament to engage in that activity.

A Regional Advisory Process (RAP) meeting was convened in November 2004 to assess the level of mortality that would not jeopardize the survival or recovery of the species. Participants included DFOscientists and fisheries managers, the provincial departments of Agriculture and Fisheries, and Natural Resources, scientists from academia and representatives from the Recovery Team. The products of this review are formal documents which provide the conclusions of the meeting (DFO 2004a), along with the Proceedings which provide details of the discussions generated in review of the working papers (DFO 2004b).These documents are available on the Department of Fisheries and Oceans website, under the Canadian Science Advisory Secretariat (CSAS).

Discussions during the review indicate that there are no estimates of abundance for Atlantic whitefish; status and trends is limited to an analysis of relative indicators of spatial occupancy (i.e., change in geographic distribution over time). Potential sources of mortality and aggregate harm, their relative rank effect by activity, alternatives to current human activities, and feasible measures to minimize impact of activities on Atlantic whitefish are presented in DFO 2004b and included fishing activities, habitat effects due to barriers to fish passage, water extraction, urbanization, eutrophication, and scientific collections.

The conclusion from the meeting was that there are no indications that current human activities (as above) within the Petite Rivière drainage pose a threat to the survival of Atlantic whitefish, however there may not be scope for further harm arising from new activities or proposed changes to existing activities because they may jeopardize the survival and recovery of the species (DFO 2004a). A scientific review of activities and any new information will be undertaken every 5 years to ensure that the survival or recovery of the species is not jeopardized. In accordance with subsection 83(4) of SARA, the recovery strategy permits the operation of the Hebb Lake Dam that is authorized pursuant to subsection 6(4) of the Navigable Waters Protection Act, R.S.C., 1985, c. N-22.

Should new activities or changes to existing activities be anticipated, an assessment of their impact on the survival and recovery of Atlantic whitefish will be undertaken.

The allowable harm assessment could not address whether current activities jeopardize the recovery of Atlantic whitefish as recovery for this species is defined as an increase in area of occupancy. Consequently, the lack of prior knowledge concerning the threats to the species outside its current area of known occupancy precludes that assessment at this time. This recovery strategy accordingly presents several options to achieve recovery (range extension); the feasibility of each option has not been determined (see Objective 2).

2.8 Recovery Effort Underway: Fish releases into Anderson Lake

The Recovery Team identified the need to establish back-up populations of Atlantic whitefish to minimize its risk of extinction. In 2004, a DFO Science workshop was held to examine decision criteria for introducing this species into a watercourse beyond its existing range, and to develop a “decision support tool” to guide the decision making process (DFO 2004c). This decision support tool was subsequently screened by a technical committee of the Recovery Team. Anderson Lake, near Burnside, in Dartmouth, Nova Scotia, was considered an acceptable candidate site according to the criteria of the tool.

On November 4, 2005, 1500 Atlantic whitefish reared at DFO's Mersey Biodiversity Facility were released into Anderson Lake as part of a three-year trial project. A second release of 750 fish occurred on April 24, 2006 and a third release of another 750 fish is scheduled to occur during the fall of 2006. In addition, a number of young-of-the-year fish was also released in April and May of 2006. DFO staff will monitor the whitefish in Anderson Lake to determine the success of the introductions.

With respect to legal protection, the SARA legislation discussed in Section 1.3 applies to the Atlantic whitefish found in Anderson Lake, as does the Fisheries Act. Section 6 of the Maritime Provides Fishery Regulations (MPFRs) also applies, however no additional protection measures (e.g., variation orders) were deemed necessary in this lake. DFOheld consultations with the owners of the land surrounding Anderson Lake (see Appendix III) prior to the releases. As well, DFO signed Working Agreements with the land owners to facilitate a cooperative approach to avoiding or mitigating any potential negative effects potentially resulting from possible future development activities around the lake.

2.9 Anticipated Conflicts or Challenges

As has been illustrated throughout this document, a major challenge facing the recovery of Atlantic whitefish is the lack of general knowledge about the species biology, its abundance and habitat requirements, as well as assessing the impact of identified threats and appropriate measures to mitigate these threats (Section 2.5).

Some of the anticipated conflicts or challenges facing the recovery of Atlantic whitefish include the following dependant on recovery actions taken:

  • (re)-introduction of the species into watersheds other than the Tusket and Petite rivers could be ecologically and socially problematic. From both ecological and management perspectives, there could be negative consequences to other recreational fisheries or resource values;
  • water control changes could impact stakeholders;
  • fishery regulatory changes could impact stakeholders, particularly recreational fishers;
  • predators and competitors such as smallmouth bass and chain pickerel may be difficult to control. The implications of the introduction of these species are not well understood and effective methods of control have not been identified. Furthermore, smallmouth bass are a popular sport fish and their presence in a watershed is not necessarily viewed by all interest groups as negative, and;
  • obtaining the financial resources and technical and scientific expertise required for timely implementation of all aspects of the recovery initiative may be problematic. It is acknowledged that there is significant demand from a wide variety of interests in our society for public and private sector funding for initiatives. Furthermore, the existing workload for many of the key contributors to this initiative is substantial.