Lake whitefish (Coregonus clupeaformis) in Lake Simcoe COSEWIC assessment and status report: chapter 11

• Previous page
• Table of contents
• Next page

Technical Summary

Coregonus clupeaformis

Lake whitefish, Lake Simcoe population – Grand corégone, population du lac Simcoe

Extent and Area information

Population Information

Threats (actual or imminent threats to populations or habitats)

• Lack of natural reproduction resulting from habitat loss due to cultural eutrophication and its effects on spawning and hypolimnetic habitat
• Inter-specific competition with introduced exotics i.e., rainbow smelt
• Potential of negative impact from introduction of zebra mussels and spiny waterfleas

Rescue Effect (immigration from an outside source)

Quantitative Analysis

Not Done

Existing Status

Nature Conservancy Ranks (Natureserve 2004)

• Global – T2
• National
  • US – N/A
  • Canada NNR
• Regional
  • US – N/A
  • Canada – ON: SNR
• Wild Species 2000 (Canadian Endangered Species Council 2001) – NR
• COSEWIC – Data Deficient (May 2005)

Status and Reasons for Designation^Footnote1

Status:  Data Deficient

Alpha-numeric code: Not Applicable

Reasons for Designation: Although this population is on its way to extirpation, there is inconclusive evidence regarding its distinctiveness and the best evidence available at this time is insufficient to resolve the species’ eligibility for assessment.

Applicability of Criteria

Criterion A (Declining Total Population): The wild component of the population has severely declined and remains depressed (A2b), habitat quality and quantity generally is degraded (A2c), exploitation continues and appears to be increasing (A2d), and exotics continue to threaten the integrity of both the ecosystem and the population (A2e); recovery may be further impacted by hatchery propagation procedures. The wild component qualifies for Endangered; the total population (wild+stocked) qualifies for Threatened; however, there is insufficient evidence to establish eligibility.

Criterion B (Small Distribution, and Decline or Fluctuation): One lake containing one population with a limited or unknown number of stocks present in a continued depressed state. The number of mature wild individuals has declined, appears to consist mostly of very old fish from recruitment events >30 years ago, thus will decline in future as these individuals die from either natural or fishing causes (B2a,b(v)). Although attempts at reversing habitat degradation have occurred and some success has been realized, rehabilitation to levels necessary for population recovery is unlikely; however, there is insufficient evidence to establish eligibility.

Criterion C (Small Total Population Size and Decline): No information regarding actual abundance is available for wild fish, but it is likely quite low relative to what should be present in a lake this size.

Criterion D (Very Small Population or Restricted Distribution): Criterion not met; however, there is insufficient evidence to establish eligibility.

Criterion E (Quantitative Analysis): Data not available; however, there is insufficient evidence to establish eligibility.