Blackfin cisco COSEWIC assessment and status report: chapter 13
Technical Summary
Coregonus nigripinnis
Range of Occurrence in Canada: Ontario
Extent and Area Information
Measured as total area of Lake Nipigon
specify trend (decline, stable, increasing, unknown)
Unknown
are there extreme fluctuations in EO (> 1 order of magnitude)?
Unknown
area of occupancy (AO) (The AO is restricted to the deeper waters of the lake, and thus would only be a fraction of the EO )
Unknown
specify trend (decline, stable, increasing, unknown)
Unknown
are there extreme fluctuations in AO (> 1 order magnitude)?
No
number of extant locations (Includes the Little Jackfish River – fish found there are probably migrants from Lake Nipigon)
Unknown
specify trend in # locations (decline, stable, increasing, unknown)
Unknown
are there extreme fluctuations in # locations (>1 order of magnitude)?
No
habitat trend: specify declining, stable, increasing or unknown trend in area, extent or quality of habitat
Unknown
Population Information
number of mature individuals (capable of reproduction) in the Canadian population (or, specify a range of plausible values)
Unknown
total population trend: specify declining, stable, increasing or unknown trend in number of mature individuals
Unknown
if decline, % decline over the last/next 10 years or 3 generations, whichever is greater (or specify if for shorter time period)
Unknown
are there extreme fluctuations in number of mature individuals (> 1 order of magnitude)?
Unknown
is the total population severely fragmented (most individuals found within small and relatively isolated (geographically or otherwise) populations between which there is little exchange, i.e., ≤ 1 successful migrant / year)?
No
list each population and the number of mature individuals in each
Unknown
specify trend in number of populations (decline, stable, increasing, unknown)
Unknown
are there extreme fluctuations in number of populations (>1 order of magnitude)?
No
Threats (actual or imminent threats to populations or habitats)
- Exploitation – continued presence as incidental catch in Lake Nipigon commercial fishery;
- historically – overfishing in lake Huron
- Competition with introduced exotics such as rainbow smelt, and spiny water flea
- Possible Introgressive Hybridization
Rescue Effect (immigration from an outside source): None
Quantitative Analysis
N/A
Status and Reasons for Designation
Reasons for Designation: Uncertainty about whether or not we are dealing with ecomorphotypes of a common and widespread species (C. artedii), or distinct populations of blackfin cisco (C. nigripinnis), cannot be resolved with the information presently available. Given this uncertainty, COSEWIC cannot unambiguously define which units it would be assessing. However, COSEWIC notes that whatever the systematic status, there are distinct coregonids in these lakes that warrant enhanced conservation and protection. The uncertainty of systematic status can probably only be resolved through a comprehensive taxonomic/systematic review of the sub-genus.
Applicability of Criteria
Criterion A (Declining Total Population):
Not Applicable – taxonomy uncertain.
Criterion B (Small Distribution, and Decline or Fluctuation):
Not Applicable – taxonomy uncertain.
Criterion C (Small Total Population Size and Decline):
Not Applicable – taxonomy uncertain.
Criterion D (Very Small Population or Restricted Distribution):
Not Applicable – taxonomy uncertain.
Criterion E (Quantitative Analysis):
Not Applicable – No data.
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