Misty Lake sticklebacks COSEWIC asessment and status report: chapter 12

Technical Summary: Misty Lake Lotic stickleback

Gasterosteus sp.

Misty Lake Lotic stickleback – Épinoche lotique du lac Misty

Range of Occurrence in Canada:

Endemic to Misty Lake, Vancouver Island, British Columbia

Extent and Area Information

Extent of occurrence (EO) (km²)
<9 km² inlet stream. Based on area of watershed for inlet form.
Specify trend in EO
Stable
Are there extreme fluctuations in EO?
May decrease in dry years
Area of occupancy (AO) (km²)
0.008 to 0.04 km² for inlet stream form. Maximum habitat available for stream form is estimated based on total length of stream and wetted widths (calculated from basin sizes and water yield (43L/s/km²)); maximum available ~ 0.04 km²; minimum from known distribution ~0.008 km².
Specify trend in AO
Stable
Are there extreme fluctuations in AO?
Will decrease in very dry years
Number of known or inferred current locations
1
Specify trend in #
Stable
Are there extreme fluctuations in number of locations?
None
Specify trend in area, extent or quality of habitat
Stable, although additional logging is scheduled to begin in 2006 in the watershed

Population Information

Generation time (average age of parents in the population
2 yr
Number of mature individuals
Unknown
Total population trend:
Both populations appear stable
% decline over the last/next 10 years or 3 generations.
Are there extreme fluctuations in number of mature individuals?
Unknown
Is the total population severely fragmented?
No
Specify trend in number of populations
Stable
Are there extreme fluctuations in number of populations?
No
List populations with number of mature individuals in each:
inlet stream – may be < 2500 (Moore pers. comm. 2006).

Threats (actual or imminent threats to populations or habitats)

Potential impacts of hydrocarbon and pesticide contamination from the adjacent highway and rest stop; habitat, water quality and hydrological changes from nearby logging or climate warming; non-native species introductions (including fish, invertebrates and plants); and non-conforming recreational uses of the lake.

Rescue Effect (immigration from an outside source)

Not Applicable – Endemic Species

Status of outside population(s)?
Is immigration known or possible?
Not possible
Would immigrants be adapted to survive in Canada?
Is there sufficient habitat for immigrants in Canada?
Is rescue from outside populations likely?

Quantitative Analysis

Current Status

COSEWIC: Endangered (2006)
B.C. Conservation Data Centre: S1

Status and Reasons for Designation

Status: Endangered

Alpha-numeric code: A3e

Reasons for Designation: This stream-dwelling fish is part of an endemic, highly divergent species pair restricted to a single stream-lake complex on Vancouver Island with an extremely small area of occurrence.  This species pair could quickly become extinct due to the introduction of non-native aquatic species or perturbations to the habitat.  Proximity of this complex to a major highway and public access makes an introduction likely.  Logging activities in the watershed, as well as highway use and related maintenance, could impact habitat quality to some degree.

Applicability of Criteria

  • Criterion A: (Declining Total Population): Met endangered A3e.  The possibility of the introduction of an exotic species is extremely high and such an event is projected to have the potential to drive the population to extinction within three generations.
  • Criterion B: (Small Distribution, and Decline or Fluctuation): Not Applicable, although the extent of occurrence and area of occupancy are less than 500 km², there is no evidence of decline or fluctuation.
  • Criterion C: (Small Total Population Size and Decline): Not Applicable, although the population size may be approaching the threshold for endangered, there is no evidence of decline.
  • Criterion D: (Very Small Population or Restricted Distribution): Met threatened D2.  An endemic with the total population in one location where it is restricted to an AO of less than 1 km².
  • Criterion E: (Quantitative Analysis): Not applicable, no data.

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