BC Conservation Data Centre: Conservation Status Report
Oncorhynchus mykiss pop. 47
Steelhead Trout - Chilcotin River Population
| Scientific Name: | Oncorhynchus mykiss pop. 47 |
|---|---|
| English Name: | Steelhead Trout - Chilcotin River Population |
| Provincial Status Summary | |
| Status: | S1 |
| Date Status Assigned: | May 15, 2019 |
| Date Last Reviewed: | April 29, 2019 |
| Reasons: | Extremely low population and steep declines. |
| Range | |
| Range Extent: | F = 20,000-200,000 square km |
| Range Extent Estimate (km2): | > 20,000 |
| Range Extent Comments: | from COSEWIC 2018d |
| Area of Occupancy (km2): | E = 26-125 |
| Area of Occupancy Estimate (km2): | < 500 |
| Area of Occupancy Comments: | from COSEWIC 2018d |
| Occurrences & Population | |
| Number of Occurrences: | Rank Factor not assessed |
| Number of Occurrences with Good Viability / Ecological Integrity: | Rank Factor not assessed |
| Number of Occurrences Appropriately Protected & Managed: | Rank Factor not assessed |
| Population Size: | B = 50 - 250 individuals |
| Comments: | 58 were found in 2017, the average of the past three years is 120 (COSEWIC 2018d) |
| Threats (to population, occurrences, or area affected) | |
| Degree of Threat: | Rank Factor not assessed |
| Comments: | A threats calculator was not complete for this population; however, "This population faces a number of threats in the marine and freshwater environments, many of which are similar to Sockeye Salmon in the Fraser River drainage and Coho Salmon in the Interior Fraser River. Fishery removals for the interior Fraser Steelhead Trout vary from 15-25% per year, depending on the abundance of salmon targeted in commercial fisheries." (COSEWIC 2018d) |
| Trend (in population, range, area occupied, and/or condition of occurrences) | |
| Short-Term Trend: | BC = Decline of 70-90% |
| Comments: | 81% decline in the past three generations (COSEWIC 2018d) |
| Long-Term Trend: | Rank Factor not assessed |
| Other Factors | |
| Intrinsic Vulnerability: | Rank Factor not assessed |
| Environmental Specificity: | Rank Factor not assessed |
| Other Rank Considerations: | "Chilcotin Steelhead Trout are endemic to this watershed and rescue is not possible from other Steelhead Trout populations. Rescue from nonanadromous trout within this watershed is unlikely." (COSEWIC 2018d) |
| Information Gaps | |
| Research Needs: | |
| Inventory Needs: | |
| Stewardship | |
| Protection: | |
| Management: | |
| Version | |
| Author: | Ramsay, L.R. |
| Date: | April 23, 2019 |
| References | |
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COSEWIC. 2018d. Technical Summaries and Supporting Information for Emergency Assessments. Steelhead Trout, Oncorhynchus mykiss, (Thompson River and Chilcotin River populations). Committee on the Status of Endangered Wildlife in Canada. Ottawa. 26 pp.
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Please visit the website Conservation Status Ranks for information on how the CDC determines conservation status ranks. For global conservation status reports and ranks, please visit the NatureServe website http://www.natureserve.org/.
Suggested Citation:
B.C. Conservation Data Centre. 2019. Conservation Status Report: Oncorhynchus mykiss pop. 47. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Jan 24, 2025).