Acipenser transmontanus (Upper Fraser River subpopulation)
| Kingdom |
Phylum |
Class |
Order |
Family |
| ANIMALIA |
CHORDATA |
ACTINOPTERYGII |
ACIPENSERIFORMES |
ACIPENSERIDAE |
| Scientific Name: |
Acipenser transmontanus (Upper Fraser River subpopulation) |
| Species Authority: |
Richardson, 1836 |
|
Common Name/s:
|
Assessment Information
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| Red List Category & Criteria: |
Endangered
B1ab(ii,iii); D
ver 3.1
|
| Year Assessed: |
2004 |
| Assessor/s: |
Down, T. & Ptolemy, J. (Ministry of Water, Land & Air Protection, Canada) |
| Reviewer/s: |
St. Pierre, R. & Pourkazemi, M. (Sturgeon Red List Authority) |
Justification:
This distinct subpopulation of white sturgeon occurs only in the upper Fraser River, upstream of the Nechako River. A preliminary estimate from work being done by the Lheidli T’enneh First Nation (Yarmish and Toth 2001) for shows a subpopulation size of 255 (95% CI = 158–352). This preliminary population estimate may be skewed by the high recapture rate of individuals found in known areas of congregation. However, after extensive sampling, investigators do not believe the population can be larger than a few hundred individuals > 50 cm in length (Yarmish pers. comm.).
|
Geographic Range
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| Range Description: |
In the Fraser River drainage of Canada at least five distinct subpopulations of white sturgeon have been identified using two independent genetic techniques - mtDNA and microsatellite DNA (Nelson et al. 1999 and Pollard 2000). The Upper Fraser subpopulation is found in the Fraser River upstream of the Nechako River. Fraser River subpopulations do not mix with the U.S. Regional population.
|
| Countries: |
Native:
Canada (British Columbia)
|
Population
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| Population: |
A preliminary estimate from work being done by the Lheidli T’enneh First Nation (Yarmish and Toth 2001) for shows a subpopulation size of 255 (95% CI = 158–352). This preliminary population estimate may be skewed by the high recapture rate of individuals found in known areas of congregation. However, after extensive sampling, investigators do not believe the population can be larger than a few hundred individuals > 50 cm in length (Yarmish, pers. comm.).
Only 19% of the fish captured in the Lheidli T’enneh study were in the > 150 cm size class (Yarmish and Toth 2001). Investigators believe the use of this size class in the latter study may underestimate the number of adult fish as maturity in this slower growing population may occur at a smaller size (Yarmish, pers. comm.).
|
| Population Trend: |
Unknown
|
Habitat and Ecology
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| Habitat and Ecology: |
Restricted to freshwater in the upper Fraser River only.
|
| Systems: |
Freshwater |
