Contorted-pod evening-primrose (Camissonia contorta) recovery strategy: chapter 4

Critical Habitat II

Figure 8. Location of critical habitat for Population 5 (Saanich B) at North Spit, James Island.

© Parks Canada Agency

Location of critical habitat for Population 5 (Saanich B) at North Spit, James Island

Figure 9. Location of critical habitat for Population 7 (Saanich D) at Sidney Island in Gulf Islands National Park Reserve.

© Parks Canada Agency

Location of critical habitat for Population 7 (Saanich D) at Sidney Island in Gulf Islands National Park Reserve

Figure 10. Location of critical habitat for Population 8 (Saanich E) at Cordova Spit Municipal Park.

© Parks Canada Agency

Location of critical habitat for Population 8 (Saanich E) at Cordova Spit Municipal Park

7.2 Schedule of Studies to Identify Critical Habitat

Further activities are required to facilitate critical habitat identification. Critical habitat will need to be identified at Population 6, where information currently does not allow for a critical identification. In addition, the population and distribution objectives recommend increasing population size at all locations, so further critical habitat identification likely will be required at all locations. And finally, the population and distribution objectives recommend that one additional population be established, so once established critical habitat will need to be identified at this location. It should be noted that several of the approaches listed in Table 4 (research; mapping, surveys and monitoring; population restoration) are required before the activities listed in Table 7 can be achieved.

Table 7. Schedule of Studies.
Description of activity Rationale Timeline
  • Obtain permission to use habitat data from Tsawout First Nation to expand critical habitat for Population 8.
  • It is known that habitat occurs on the Tsawout Indian Reserve that would be appropriate for expansion habitat, but permission to the use the data has not yet been granted.
Complete by 2011
  • Survey and map Population 6 to facilitate the inclusion of this site into the critical habitat identification.
  • Currently it is not known if plants still occur at this location (last seen in 2007, but not known where at the location they were seen), so surveys and mapping are required before critical habitat can be identified.
Complete by 2012
  • Map and identify critical habitat for expanded populations.
  • After completing research and restoration work recommended in Table 4, some populations will have expanded populations that will require new mapping to ensure that all occupied habitat is included in the identification of critical habitat to ensure the population and distribution objectives can be met.
Complete by 2020
  • Map and identify critical habitat for the one new population that will be established.
  • The population and distribution objectives recommend the establishment of one new population. Once established, critical habitat will need to be identified.
Complete by 2020

7.3 Activities Likely to Result in the Destruction of Critical Habitat

The primary threats to Contorted-pod Evening-primrose critical habitat include loss or degradation of habitat from land development, recreation and/or exotic/invasive species. These threats can remove habitat completely or reduce its ability to provide the attributes necessary for population viability. The habitat attributes considered necessary for the survival or recovery of Contorted-pod Evening-primrose are outlined in Section 7.1.1.

Destruction must be determined on a case-by-case basis. Destruction would result if part of the critical habitat were degraded, either permanently or temporarily, such that it would not serve its required function for Contorted-pod Evening-primrose. Destruction may result from single or multiple activities at one point in time or from the cumulative effects of one or more activities over time. Destruction may originate from activities inside or outside of critical habitat polygons.

It is recognized that existing facilities and land uses in and adjacent to critical habitat already affect critical habitat, to various degrees, and may decrease the quality of certain portions of critical habitat. Lower quality or sub-optimal areas may nonetheless be included as critical habitat because they serve a biological function for the species (e.g., expansion habitat). Any new, additional, or increases in activity (including the construction of new facilities) inside or outside of critical habitat polygons may cause destruction of critical habitat. Some human activities in or adjacent to critical habitat will require careful assessment for possible effects, including cumulative effects on critical habitat and the potential for destruction.

Examples of scenarios that can damage or destroy critical habitat include, but are not limited to:

Habitat loss and destruction – direct destruction or loss of critical habitat can occur from the construction of buildings, breakwaters, golf courses, foot paths, roadways, transmission lines, and other similar activities, as well as from the introduction of exotic or invasive species. All these activities can completely remove all the habitat attributes that Contorted-pod Evening-primrose requires.

Habitat degradation – critical habitat can be degraded by nearby development such as buildings, footpaths or breakwaters, from the introduction of exotic or invasive species, and from recreational uses such as hiking, dog walking and off-road vehicle use. Degradation from these and other activities can occur through increased erosion (e.g., a breakwater can alter water flow and affect erosion), shading (e.g., structures can block sunlight), compaction or churning of sand or soil substrate (e.g., from vehicle use or running dogs), impacts to sand supply and sand dynamics (e.g., structures can block sand supply) and pollution (e.g., stormwater or pesticide use can poison plants and the environment they depend on).

It is important to note that a minimal level of activities such as hiking or dog walking may not result in destruction of critical habitat because this species likely is adapted to a low level of disturbance. However, it is not currently known how much of such activities can be absorbed by a population before the activities would be defined as destruction. All other activities listed above may cause destruction at any level of impact.

The introduction of invasive plant species occurs largely as a result of human activity and is included in this section because the quality of critical habitat will not be maintained if the spread of invasive species is not controlled.

Areas surrounding these critical habitat areas may require specific management action to provide effective conservation to the populations of Contorted-pod Evening-primrose. For example, structures placed outside the critical habitat polygon may still create shading or affect sand movement and therefore could result in degradation of habitat that would be considered destruction. Land owners and managers should exercise caution when working near these critical habitat areas.

8. Measuring Progress

The performance indicators presented below provide a way to define and measure progress toward achieving the population and distribution objectives. Specific progress towards implementing the recovery strategy will be measured against indicators outlined in subsequent action plans.A successful recovery program will achieve the overall aim of attaining nine viable, self-sustaining and protected populations of Contorted-pod Evening-primrose distributed throughout its historical extent of occurrence in Canada. Listed here are performance indicators for the four population and distribution objectives.

  1. Maintain the known extent of occurrence for the species in Canada (by 2015).
    • By 2015, there has been no reduction in the known extent of occurrence for the species.
  2. Maintain population sizes for all extant locations at current or higher levels (by 2015).
    • By 2015, population sizes have been maintained at current or higher levels (note, the population sizes listed in Table 1 are considered current).
  3. Recover all eight extant populations to no less than their minimum viable population size (by 2020).
    • By 2015, propagation and translocation methods have been established to facilitate population augmentation.
    • By 2020, all eight extant populations are recovered to at least a minimum viable populations size (note, minimum viable population size will be defined during action planning).
  4. Establish one additional population (to replace the single known extirpated population) at a site with suitable habitat within the historical range of the species in Canada, and maintain it at no less than its minimum viable population size (by 2020).
    • By 2020, one further site has been established either at the extirpated Cedar Hill location or elsewhere in the historical range of the species.
    • By 2020, the new site has a population size that is no less than the minimum viable population size for the species (note, minimum viable population size will be defined during action planning).

9. Statement on Action Plans

One or more action plans for Contorted-pod Evening-primrose will be posted on the SARA Public Registry by March 2015.

10. References

B.C. Conservation Data Centre. 2011. B.C. Species and Ecosystems Explorer. B.C. Ministry of Sustainable Resource Management. Victoria, British Columbia, Canada. Available: (Accessed: January 21, 2011).

B.C. Conservation Framework. 2010. Conservation Framework Summary: Camissonia contorta. BC Ministry of Environment. Available from: (accessed September 10, 2010).

B.C. Ministry of the Environment. n.d. Ecoregions of British Columbia. (Accessed April 2011).

B.C. Ministry of Forests. 2003. Biogeoclimatic Ecosystem Classification Subzone/Variant Map for South Island Forest District, Vancouver Forest Region. Victoria, British Columbia. 1:300,000.

COSEWIC 2006. COSEWIC assessment and status report on the contorted-pod evening-primrose (Camissonia contorta) in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. vi + 21 pp. ( (Accessed September 2006).

Fairbarns, M.D. 2004. Potential Recovery Actions for Contorted-pod Evening-primrose In CRD Parks. 16 pp.

Government of Canada 2009. Species at Risk Act Policies, Overarching Policy Framework [Draft]. Species at Risk Act Policy and Guidelines Series. Environment Canada, Ottawa. 38 pp.

Hitchcock, C.L., A. Cronquist, M. Ownbey and J.W. Thompson. 1961. Vascular plants of the Pacific Northwest volume 3: Saxifragaceae to Ericaceae. University of Washington Press. Seattle. 614 pp.

NatureServe. 1988. NatureServe Explorer: An online encyclopedia of life [web application]. Version 4.6. NatureServe, Arlington, Virginia. Available (Accessed: November 1, 2010).

Pavlik, B.M. 1996. Defining and measuring success. In: Restoring Diversity: Strategies for Reintroduction of Endangered Plants. D.A.Falk, C.I.Millar and M.Olwell (eds), pp. 127-156. Island Press, Washington D.C.

Traill, L.W., C.J.A. Bradshaw and B.W. Brook. 2007. Minimum viable population size: a meta-analysis of 30 years of published estimates. Biological Conservation 139:159-166.

Turner, Don. 2006. Telephone conversation, October 4, 2006. Regional Planner, Powell River Regional District. 604-483-2229.

Webster, Liz. 2006. E-mail communication, October 4, 2006. Executive Director, Savary island Land Trust Society.

Appendix A: Effects on the Environment and Other Species

A strategic environmental assessment (SEA) is conducted on all SARA recovery planning documents, in accordance with the Cabinet Directive on the Environmental Assessment of Policy, Plan and Program Proposals. The purpose of a SEA is to incorporate environmental considerations into the development of public policies, plans, and program proposals to support environmentally sound decision-making.

Recovery planning is intended to benefit species at risk and biodiversity in general. However, it is recognized that strategies may also inadvertently lead to environmental effects beyond the intended benefits. The planning process based on national guidelines directly incorporates consideration of all environmental effects, with a particular focus on possible impacts upon non-target species or habitats. The results of the SEA are incorporated directly into the strategy itself, but are also summarized below in this statement.

This recovery strategy will clearly benefit the environment by promoting the recovery of the Contorted-pod Evening-primrose. Activities to meet recovery objectives are unlikely to result in any important negative environmental effects, as they are limited to habitat protection, research activities, fostering stewardship, increasing public awareness, improving knowledge on habitat requirements and population threats, and conducting habitat/species mapping, inventory and restoration.

The recovery strategy identifies current threats (Section 4) to the Contorted-pod Evening-primrose and its habitat as well as current knowledge gaps (Section 6.2). Recovery objectives clearly focus on resolving these threats and filling information gaps. The greatest potential for environmental effects comes from fieldwork activities aimed at population restoration (e.g. invasive species removal and restoration of natural sand dynamics), however these effects can be mitigated at the project level phase with known technology and proper field procedures. Activities may also benefit non-target species and the environment (Table 9).

Some recovery strategy activities (e.g. translocations and habitat restoration) may require project-level environmental assessment as required under the Canadian Environmental Assessment Act (CEAA). Any activities found to require project-level environmental assessments will be assessed at that time pursuant to the provisions of the Act. The SEA process has concluded that this recovery strategy will have several positive effects on the environment. No important negative effects are expected.

A number of other species at risk have been reported from the vicinity of one or more extant populations of Contorted-pod Evening-primrose. These species are listed in Table 9 to ensure land managers are able to consider all relevant species when designing management actions.

Although overall the strategy for the recovery of Contorted-pod Evening-primrose is positive for the environment in general, there is some potential for negative effects on non-target species, natural communities and natural processes. For example, invasive species removal may have negative impacts on species at risk, plant communities and natural processes. These can be avoided or minimized by:

  • surveying and marking the occurrence of species at risk in the treatment areas prior to commencing control treatments, to avoid trampling damage.
  • conducting treatments during the dormant season for other species at risk.
  • avoiding non-target herbicide impacts by directly applying herbicides to the target plants.
  • avoiding soil disturbance by using low-impact techniques to remove invasive species (e.g., removing Scotch broom using loppers and secateurs rather than weed wrenches).
Table 9. Co-occurring species at risk. Status: E = Endangered, T = Threatened, SC = Special Concern, NAR = Not at Risk, P = Proposed for COSEWIC listing, NA = Not Assessed. S-ranks assigned by as per B.C. Conservation Data Centre and NatureServe.
Species Common name Conservation Rank COSEWIC Status
Copablepharon fuscum Sand-verbena Moth S1 E
Carex tumulicola Foothill Sedge S2 P
Psilocarphus tenellus var. tenellus Slender Woollyheads S2 NAR
Leymus triticoides Creeping Wildrye S1 NA
Lathyrus littoralis Grey Beach Pea-vine S2 NA
Coenonympha tullia ssp. insulana Island Common Ringlet S2 NA
Triglochin concinna Graceful Arrow-grass S2 NA
Jaumea carnosa Fleshy Jaumea S2S3 NA
Convolvulus soldanella Beach Morning-glory S3 NA
Hesperia colorado ssp. oregonia Western Branded Skipper S3 NA
Abronia latifolia Yellow Sand-verbena S3 NA
Glehnia littoralis ssp. leiocarpa American Glehnia S3 NA
Polygonum paronychia Black Knotweed S3 NA
Carex macrocephala Large-headed Sedge S3S4 NA
Claytonia rubra ssp. depressa Low Redstem Springbeauty S3S4 NA


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