Green sturgeon (Acipenser medirostris) COSEWIC assessment and status report: chapter 14
Technical summary
Green sturgeon
Esturgeon vert
Range of Occurrence in Canada: British Columbia (BC)
Extent and area information
[Estimated from Figure 4 ]
Population information
Threats (actual or imminent threats to populations or habitats)
Anthropogenic activities known to impact sturgeons include: blockage of available freshwater spawning habitat through diking, damming causing inadequate flow regimes, channelization, elimination of backwater areas, dewatering of streams, destruction of thermal refugia, loss of deep pools, inundation of habitat by reservoirs, exposure to bioaccumulating industrial and municipal pollution, and overfishing. With the exception of overfishing, the majority of these impacts are restricted to the freshwater phases of green sturgeon life history. As green sturgeon are rarely captured in freshwater in Canada, negative anthropogenic impacts outside fishing may be more limiting to individuals utilizing spawning and rearing habitat in the US.
Rescue effect (immigration from an outside source): Moderate
Quantitative Analysis
Not Applicable
Existing status
Nature Conservancy Ranks
Global - G3
National
US - N3
Canada N3N
Regional
US - Alaska - S4N, California S2S2, Oregon S3, Washington S3N
Canada - BC S3N
International Union for Conservation of Nature (IUCN) - Vulnerable
US Endangered Species Act - Candidate species
Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) - Appendix II
Committee on the Status of Endangered Wildlife in Canada (COSEWIC) - SC 1987
Status and reasons for designation
Reasons for Designation: The number of individuals in Canadian waters is unknown, but is undoubtedly not large. This species is globally at risk and is of concern in Canada because of exploitation and habitat loss due to damming of rivers.
Applicability of criteria
Criterion A (Declining Total Population): Not applicable, no evidence of population decline.
Criterion B (Small Distribution, and Decline or Fluctuation): Not applicable, AO and EO larger than threshold values and there is no evidence of decline or fluctuation.
Criterion C (Small Total Population Size and Decline): Not applicable, population size and trends not known.
Criterion D (Very Small Population or Restricted Distribution): Not applicable, although the Canadian population is undoubtedly small, the number of mature individuals is unknown, the area of occupancy is certainly larger than the threshold value, and the number of locations at which the species is found is uncertain.
Criterion E (Quantitative Analysis): Not applicable - no data.
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