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If you have any questions on the information presented, or require additional report data or attachments, please contact the Report Contact
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Between February 4 and May 14, 2004, a series of six snorkel surveys were conducted to
estimate steelhead escapement in the Englishman River watershed.
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Author: Silvestri, S.; BC Conservation Foundation
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Date Published: Dec 2004
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Report ID: 5848
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Audience: Government and Public
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The 2004 survey marks the third consecutive year of intensive steelhead enumeration by BCCF
and MWLAP staff in the Englishman and South Englishman rivers. Estimates of adult
escapement using snorkel techniques, smolt emigration using rotary screw traps, and fry
standing stocks through closed-site electrofishing further develop the Englishman River as a
key steelhead index stream on the east coast of Vancouver Island.
Results from six snorkel surveys between February 4 and May 14 were evaluated using the
AUC method to estimate a probable range of steelhead escapements. Observer efficiency and
average residence time of Englishman steelhead were established based on radio-telemetry
results from previous Vancouver Island studies, historical snorkel survey data from the
Englishman watershed, and observations made during the 2002, 2003 and 2004 studies.
The AUC estimate for 2004, assuming an average residence time of 60 days and an average
observer efficiency of 60%, was 85 steelhead (most probable range: 58-136). This compares to
estimates of 145 and 96 for 2002 and 2003, respectively, using the same observer efficiencies
and residence times. Until these assumptions are tightened up if not eliminated, estimate
confidence will not improve significantly. However, actions required to address these
assumptions (mark-recapture component) may be too invasive given the extreme conservation
concern associated with this stock.
Given the importance of Englishman River steelhead, collection of abundance trend data should
continue in 2005. Further development of the Englishman River as a key index stream for
winter steelhead populations in the Georgia Basin is a high priority outlined in the Greater
Georgia Basin Steelhead Recovery Action Plan (Lill 2002).
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Report Type
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Fish and Aquatic Habitat Information |
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Subject
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Biogeoclimatic Zone - CDF Coastal Douglas-fir Zone |
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Biogeoclimatic Zone - CWH Coastal Western Hemlock Zone |
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Fish Species - Steelhead - Oncorhynchus mykiss |
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Fish and Fish Habitat - Fish Inventory |
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Fish and Fish Habitat - Management |
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Fish and Fish Habitat - Stock Assessment |
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Watershed Groups - 920 - Vancouver Island (East) Rivers |
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