Introduction
The spawning channel in Seton River is a vital pathway to allow the Pink and Coho salmon to spawn in the rivers of Seton located near Lilloet in the southern coastal mountains, British Columbia. In 2003 a project funded by Bridge Costal Program was initiated to improve the spawning channel and enhance the habitat for Pink and Coho salmon and other aquatic fauna.
Background
The Lower Spawning Channel was constructed in 1967 due to the construction of a dam hindering salmon and other fish species to spawn in the Seton River. The International Pacific Salmon Fisheries Commission originally constructed two channels, one in the upper end of the lake reservoirs and one in the lower. The channels should mitigate loss of about 15,000 square meters of spawning substrate that was lost when the dam was constructed, and today the two channels accommodate approximately 46,000 pink salmon spawning. The channel is located on the left bank, downstream of the Seton Dam and is 3.1 km long and 6.1 m in width.
Methods and results
The project ran in two stages. First stage was a fish salvage conducted with the purpose of draining the channel for fish to allow dewatering of the channel for construction. The fish salvage was done using different catching-methods including gee-trapping and electro-fishing. The fish caught alive were transported to the upper spawning channel and set free. To assess the aquatic fauna of the Seton River all caught fish were identified and counted. A total of 4954 fish were caught and 12 fish species were identified.
Second stage marked the construction of the habitat improvements. The channel was scarified to prevent compaction and was filled with rocks, gravel and woody materials, forming the ideal environment for spawning and for eggs to survive. A new marsh habitat was constructed to promote vegetation and fostering of aquatic insects, which are an essential food source especially for juvenile salmon. 18 rocks were converted into Newbury style wiers to allow access for adult and juvenile salmons. The wiers add habitat diversity to the channel and create a high gradient reach. Additionally four large pools were excavated and constrictions were made at eleven places along the channel.
Conclusion and suggested action
The result of the Lower Spawning Channel enhancement have lead to an improved biodiversity in the Seton river. The Lillooet Naturalist Society have documented an increased wildlife in the area, but a further assessment of the aquatic fauna should be conducted within the channel to allow a scientific comparison. It is recommended that the Lower Seton Channel will continue to enhance the habitat of the spawning channel and it is believed that a continuous effort will increase the biodiversity of the river. Stakeholders are encouraged to continue educating through tourism and studies within the community.
- Source Bonnie Adolph. January 2003. Lower Seton Spawning Channel Complexing Project 2003. Prepared by Cayoose Creek Fisheries, for Bridge Coastal Restoration Program. Available at : https://a100.gov.bc.ca/pub/acat/documents/r40725/03SE01_Seton_1388766571649_8760999445.pdf [Accessed 03/2021].