| Report Documents
|
- 2001-2002 Arctic Grayling (Thymallus arcticus) Fry Surveys in the Omineca and Osilinka Rivers
Two large tributary streams of the Williston Reservoir (the Omineca and Osilinka Rivers) were examined to determine Arctic grayling distribution, relative abundance and habitat use. The objectives of the study were to: determine the distribution and relative abundance of Arctic grayling fry in these watersheds, identify critical habitats (spawning and early rearing areas) for habitat protection purposes, and compare habitat use with those found in other areas.
(pdf/409.9 Kb)
|
| |
| Map Plotfiles
|
-
No files of this type available
|
| |
| Data Files
|
-
No files of this type available
|
| |
| Digital Map Files
|
-
No files of this type available
|
| |
| Image Document
|
-
No files of this type available
|
| |
| Video Files
|
-
No files of this type available
|
| |
|
All Documents
|
|
|
| Contact
|
|
-
If you have any questions on the information presented, or require additional report data or attachments, please contact the Report Contact
|
|
|
Two large tributary streams of the Williston Reservoir (the Omineca and Osilinka Rivers) were examined to determine Arctic grayling distribution, relative abundance and habitat use. The objectives of the study were to: determine the distribution and relative abundance of Arctic grayling fry in these watersheds, identify critical habitats (spawning and early rearing areas) for habitat protection purposes, and compare habitat use with those found in other areas.
|
Author: Cowie, D.M.; Blackman, B.G.
|
Old Reference Number: PWFWCP Report No. 276
|
Old Reference System: FWCP Fish Wildlife Compensation Program Peace
|
Date Published: Nov 2003
|
Report ID: 39502
|
Audience: Government and Public
|
Arctic grayling (Thymallus arcticus) were once widely distributed throughout the Williston Watershed. Evidence now suggests that over the past few decades, populations of grayling have declined. Many studies are currently being conducted to try and determine the status of the species. As part of these ongoing investigations, two large tributary streams of the Williston Reservoir were examined to determine Arctic grayling distribution, relative abundance and habitat use. Backpack electrofishing was used to look for the presence/absence in the Omineca and Osilinka Rivers. The grayling fry habitat use was compared to studies conducted on the Table/Anzac Rivers in the Parsnip River drainage. Angling surveys were also conducted to collect information on adult distribution.
The Omineca River, 219.5 km in length with a drainage area of 5,851 km2, was examined in 2001. One hundred and five sites were examined and Arctic grayling fry were found in sixtythree sites, distributed throughout the Omineca mainstem and in three major tributaries (Carruthers Creek, Ominicetla Creek and Silver Creek). No barriers were identified on the Omineca River. Limited resource activity has taken place in this drainage.
The Osilinka River, 141 km in length with a drainage area of 2,051 km2, was examined in 2002. Seventy-three sites were examined and Arctic grayling fry were captured in eleven sites. The fry were limited to a 38 Km section of the lower Osilinka mainstem. Eighty-five percent of the grayling fry captured from the Osilinka River were caught in isolated pools on mainstem gravel bars. No grayling were caught in any of the tributaries sampled. No barriers were identified on the Osilinka River. Extensive resource activity is evident within the Osilinka watershed.
Arctic grayling fry caught were primarily associated with gravel/fine substrate habitat in both systems. The grayling in the Omineca utilized a broader range of habitats than grayling in the Osilinka River. The Omineca grayling sites average substrate content was 54% gravel/fines, while the Osilinka River average was 76% gravel/fines. In the Table and Anzac Rivers, in the southern region of the Williston Drainage, Arctic grayling showed a reference for shallow low velocity habitat with a high fines content and avoided areas with cobble substrate.
|
Report Type
| |
Fish and Aquatic Habitat Information |
| |
Subject
| |
Fish Species - Arctic Grayling - Thymallus arcticus |
| |
Region - Omineca |
| |
Fish and Fish Habitat - Fish Inventory |
| |
Watershed Groups - 238 - Omineca River |
| |
|
|
