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Recovery Strategy for Hotwater Physa
Recovery : Objectives and feasibility
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.
Table 2.Recovery criteria used to assess technical and biological feasibility of recovery for Hotwater Physa.
|Recovery Criteria||Hotwater Physa|
|1. Are individuals capable of reproduction currently available to improve the population growth rate or population abundance?|
See discussion below.
|2. Is sufficient habitat available to support the species or could it be made available through habitat management or restoration?|
See discussion below.
|3. Can significant threats to the species or its habitat be avoided or mitigated through recovery actions?|
See discussion below.
|4. Do the necessary recovery techniques exist and are they known to be effective?|
See discussion below.
- Are individuals capable of reproduction currently available to improve the population growth rate or population abundance?
- Is sufficient habitat available to support the species or could it be made available through habitat management or restoration?
- Can significant threats to the species or its habitat be avoided or mitigated through recovery actions?
- Do the necessary recovery techniques exist and are they known to be effective?
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.
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.
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.
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 (COSEWIC 2000) 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.
- Threatsmonitoring- 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.
Table 3 lists the types of recovery activities to be considered in the development of the action plan (Section 2.7).
Table 3.Summary of the broad approach/strategy, specific activities and outcomes or deliverables to be considered for the recovery of Hotwater Physa.
|Broad Strategy||Recovery Objective Number||Threat||Priority||Specific Activities||Outcomes or Deliverables|
|1. Monitoring||1, 2||All||High|
· Establish a standardized protocol for population monitoring, habitat occupancy and distribution surveys. Protocol should include habitat where the snail is not known to occur
· Map the distribution and population information throughout the hotsprings complex
· Allows park staff to make informed decisions about where to limit accessibility to hotsprings (e.g. strategic placement of boardwalks, fences and interpretive signs), and thus prevent the public from destroying the hotsprings aquatic and riparian habitat where snail densities are highest. Identify high priority sites requiring further protection.
· Assessment and monitoring of population status and recovery.
· Mapped population densities and information about habitat specificity (critical habitat).
|2. Protection||1, 2||All||Medium|
· Update the Liard River Hotsprings Provincial Park Master Plan and include provisions for the construction of boardwalks, as necessary
· Develop a quick response plan for retrieving snails in the event of a natural catastrophic event
· Record and assess the impact of physical changes to the habitat by humans (physical destruction of habitat, trampling, etc)
· Apply to obtain a water license for conservation purposes on the hotsprings output
· In the event an interest in oil and gas or geothermal exploration arises, develop and implement guidelines to mitigate the potential impacts to geothermal sources.
· Develop a weir maintenance protocol for park staff
· Evaluate necessity and means to restrict public access to critical habitat
· Documentation of mortality of snails, Chara and destruction of tufa as a direct result of humans (e.g. trampling).
· Documented observations regarding the effects of natural barriers, changes in channel structure, riparian vegetation, etc., and how it affects flow regime.
· Park staff and those concerned with changes to the weir can make informed decisions regarding changes to the in-stream structures.
· Protection of the source water system.
· Protection of critical habitat within the park.
|3. Threats Monitoring||1, 2||1, 2, 3, 4||Medium|
· Evaluate the effectiveness of measures used to prevent deleterious substances entering the hotsprings water (e.g., water sampling or monitoring of park users’ habits)
· In the event the levels of deleterious substances are found to be a concern, evaluate the effect on the snail
· Monitor the introduction of natural sedimentation and changes to riparian structure into the hotsprings complex
· Document introduction of invasive species and if invasive species are introduced develop an invasive species management strategy
· In the event there is an interest in development (e.g oil and gas exploration or hydroelectric), define the risks to the source water from the industrial activity outside of the park boundaries
· Documentation of infractions to the deleterious substance policy for park users.
· Documentation of the effects of bathers on the habitat, and how infrastructure can be improved to mitigate destruction caused by direct human causes.
· Information for establishing an invasive species management strategy for the park.
· Control of introduced vegetation and plants within the park.
· Document the rate of colonization, expansion or occupancy of introduced species and the likely effects on the snails.
|4. Knowledge Gaps||1, 2||All||Low-Medium|
· Undertake genetic studies to confirm that P. wrighti is a distinct species
· In the event population surveys determine that there is a decline in the population, and the cause can not be identified, develop a research plan to identify the cause
· In the event P. wrighti is not a distinct species, this may establish the existence of a pool of individuals for re-establishment of the Liard hotspring population given a transient catastrophic event.
· Clarification of the threats to the species and the severity when these threats are combined with the biologically limiting factors.
· Information on biologically limiting factors.
|5. Park Education||1, 2||All||Medium||· Develop a communications strategy, as necessary, to minimize impact from recreational users|
· Strategically placed signage for park users.
· Information and signage to public users regarding the intentional/ unintentional introduction of species into hotsprings complex.
· Accurate information to bathers.
· Support to the park Master Plan.
- Date Modified: