Recovery Strategy for Hotwater Physa (final)
Biologically, the species has likely persisted in this hotsprings complex since the retreat of the glaciers approximately 8,000 years before present and may have persisted throughout glacial events (Section 1.2). The species has continued to perpetuate itself within this ecosystem since its initial recording in 1973. However, a small and spatially isolated population, small occupied area of population, and habitat specificity make the species vulnerable to stochastic events.
2.1 Recovery Goal
The recovery goal for Hotwater Physa is to maintain and protect the population(s) of Hotwater Physa within its natural geographic range and within its current variation of abundance at the Liard River Hotsprings complex.
There is no current or historic evidence of a population decline, and therefore the recovery goal is to maintain the current population. Since the species has presumably been located at Liard River Hotsprings since the last glacial event, the species presumably is able to maintain its current population provided the threats to the species are minimized.
2.2 Rationale for Recovery Feasibility
The recovery of Hotwater Physa is considered feasible. The following criteria (summarized in Table 2) were used to make this assessment.
|Recovery Criteria||Hotwater Physa|
|1. Are individuals capable of reproduction currently available to improve the population growth rate or population abundance?||Yes.|
See discussion below.
|2. Is sufficient habitat available to support the species or could it be made available through habitat management or restoration?||Yes.|
See discussion below.
|3. Can significant threats to the species or its habitat be avoided or mitigated through recovery actions?||Yes.|
See discussion below.
|4. Do the necessary recovery techniques exist and are they known to be effective?||Yes.|
See discussion below.
- Are individuals capable of reproduction currently available to improve the population growth rate or population abundance?
The population(s) within the park appears to be self-replacing, as the species is stable or increasing (Section 1.3), and it is not necessary to supplement these populations at this time.
- Is sufficient habitat available to support the species or could it be made available through habitat management or restoration?
The snail is surviving and appears to be stable in its current habitat. This habitat is largely intact, at least since the dam development at Alpha Pool prior to 1973. It is not clear if any modifications or habitat restoration associated with the dam or weir would provide a net benefit to the Hotwater Physa as the current known habitat relies on the integrity of these man-made structures. Further development within the hotsprings complex is not planned, and efforts to protect the fragile ecosystem, hotsprings marsh and aquatic habitat are ongoing. Examples to avoid habitat destruction could include elevated boardwalks connecting the hotsprings habitats, limited access to hotsprings waters, and no expansion of the camping facilities within the park.
- Can significant threats to the species or its habitat be avoided or mitigated through recovery actions?
The feasibility of mitigating the major threats to the snail is highly possible. The species is protected under current legislation and changes to management activities are possible, although some strategies may be socially controversial as this is one of the most popular destinations in northern BC.
- Do the necessary recovery techniques exist and are they known to be effective?
The recovery techniques that exist are likely to be effective. Techniques used to recover this species are similar to the recovery planning applied to species with similar threats, issues and requirements, both from ecological and social perspectives. There are no highly experimental recovery techniques proposed. Currently, captive breeding to supplement wild populations and locations is not thought necessary for the recovery of Hotwater Physa, although captive bred populations could be used to gain knowledge regarding this species life history and reproductive capabilities if required.
2.3 Recovery Objectives
The current understanding of abundance of Hotwater Physa and distribution within the Liard River Hotsprings is limited and quantification of population abundance and/or distribution objectives is not possible at this time. The population estimates that have been calculated (COSEWIC2000) are not sufficient on which to set measurable objectives at this time due to the uncertainty around repeatability of sampling methodology. Further studies and the development of a standard sampling protocol will allow population estimates to be better determined (Section 2.4).
The short term objectives that will be used to monitor recovery of the Hotwater Physa over the next 5 years are:
- to observe that the species current distribution within the Alpha and Beta pools and streams is maintained, and to refine the understanding of the current distribution to better quantify this objective by 2011; and
- to observe that the species current relative abundance is maintained, and to develop methodology that increases survey precision by 2011.
2.4 Strategies to address threats and effect recovery
The Hotwater Physa and its habitat is contained and protected within the Liard River Hotsprings Provincial Park and also protected under SARA. However, there is a need to make sure that the population remains stable (or increasing) and does not decline as a result of the identified, or new, threats. The broad strategies taken to address threats to Hotwater Physa and effect recovery are:
- Monitoring - develop standardized population and habitat assessment protocols to monitor the population.
- Protection - review the Liard River Hotsprings Park Master Plan and consider additional options to protect habitat within the park, develop habitat restoration plans, if required, and develop guidelines to protect the geothermally heated water from its source to where it surfaces within the Park.
- Threats monitoring - monitor the threats to Hotwater Physa.
- Knowledge gaps - determine through genetic studies whether there are other populations of P. wrighti outside Liard hotsprings that may provide a possible rescue effect. Provide support to the identification of new threats in the event there is decline in the population from unknown cause(s).
- Park education - minimize impacts to the Hotwater Physa and their habitat from recreational users within the park.
|Broad Strategy||Recovery Objective Number||Threat||Priority||Specific Activities||Outcomes or Deliverables|
|1. Monitoring||1, 2||All||High|
|2. Protection||1, 2||All||Medium|
|3. Threats Monitoring||1, 2||1, 2, 3, 4||Medium|
|4. Knowledge Gaps||1, 2||All||Low-Medium|
|5. Park Education||1, 2||All||Medium|
2.5 Effects on other species
Recovery activities that will protect Hotwater Physa may also protect additional invertebrate and plant species at risk within the park. The only BClocation for Ischnura damula (Order Odonata) commonly known as the plains forktail damselfly is found at Liard River Hotsprings. The mayfly Caenis youngi, known to occur in the Yukon, Northwest Territories and Alaska was found within the Liard river hotsprings complex within the park (Salter 2003). The Hotwater Physa is known to be globally rare (G1 rating) and is ranked critically imperilled because of extreme rarity (S1 rating) in BC.
The lake chub fish, Couesius plumbeus, at Liard River Hotsprings Provincial Park have received special attention. Although not a distinct species, the chub at Liard are physically isolated, adapted to their thermally enhanced environment and have been examined by COSEWIC and designated as data deficient (COSEWIC 2004). Hotwater Physa and Lake Chub habitat overlap in many areas of the hotsprings complex.
The plants found at Liard River Hotsprings Provincial Park include the provincially blue-listed Carex heleonastes(Hudson Bay sedge), Carex tenera (tender sedge), Malaxis brachypoda (white adder's-mouth orchid) and Lupinis kuschei (Yukon lupine). There is also Sanicula marilandica (snake root), Urtica dioca ssp. lyallii (stinging nettle) and Mimulus guttatus(monkeyflower), which are only present at this latitude because of the thermal hotsprings environment.
The goals, objectives and strategies that are outlined herein will be reviewed within five years of the Recovery Strategy's acceptance by the Minister. The following performance measures will be used to assess the effectiveness of the objectives and strategies, and to determine whether recovery remains feasible. Detailed performance measures will be identified more fully during the development of the action plan.
Objective-based evaluation criteria that will be used to measure whether the species' status is heading towards meeting the recovery goal are:
- Was Hotwater Physa's current distribution within the Alpha and Beta pools complexes and outlet streams maintained through 2011. Is there a better understanding towards quantifying this objective by 2011?
- Was Hotwater Physa's current relative abundance maintained through 2011. Was a methodology developed to increase survey precision by 2011?
Strategy-based evaluation criteria that will be used to evaluate progress towards meeting the recovery goal are:
- Was population monitoring carried out? Was a standardized protocol for population monitoring and habitat assessment developed?
- Was the Liard River Hotsprings Park Master Plan reviewed. Were additional options to protect habitat within the park considered.
- Has the understanding of threats to Hotwater Physa been improved? How?
- Were any genetic studies undertaken and, if so, did the distinct species status of Hotwater Physa change? In what way. Does this knowledge assist the recovery plans for Hotwater Physa? Was there a decline in the population that requires new research studies to be identified. What studies are needed or were carried out?
- Did awareness of the Hotwater Physa and their habitat improve protection?
2.7 Statement on Action Plans
An action plan provides the specific details for recovery implementation, including measures to monitor and implement recovery, address threats and achieve recovery objectives, and when these measures are to take place. The action plan also includes an identification of critical habitat(s), to the extent possible, and examples of activities that are likely to result in its destruction. It also recommends measures to protect critical habitat(s) and identifies any portions of critical habitat(s) that have not been protected. An evaluation of the socio-economic costs of the action plan and benefits to be derived from its implementation is also included. An action plan will be completed by 2011.
2.8 Recommended Approach for Recovery Implementation
Currently, a single-species approach has been adopted. However, an ecosystem-based approach may be necessary to protect the entire hotsprings area. The Liard River Hotsprings ecosystem has unique flora and fauna at a regional and national level and there is the possibility that additional species in this ecosystem type will be designated at risk by COSEWIC. Where species occupy similar habitat and face similar threats, the activities required for their recovery will be common. The integration of research activities will ensure more efficient use of effort.
Hotwater Physa is currently integrated into the Liard River Hotsprings Provincial Park Master Plan. Provisions for this species' protection and management are outlined in the plan, with the ability to adapt management objectives according to new information.
- Date Modified: