Salmon stream restoration
The Lyall Creek story
Lyall Creek has been called the "backbone" of Saturna Island. The creek flows into Lyall Harbour and is home to sea-run cutthroat trout, chum and coho salmon.
Only four kilometres in length, the creek is one of the few remaining salmon-bearing streams in the southern Gulf Islands.
Salmon contribute to the health of coastal ecosystems by returning valuable marine-derived nutrients to the forest ecosystem.
Lyall Creek is also one of the only protected watersheds in the southern Gulf Islands. In a heavily urbanized region where development pressures are extending from the Lower Mainland and Vancouver Island out onto the islands of the Strait of Georgia, Lyall Creek's protection within a national park reserve ensures that an important part of the Gulf Islands' natural heritage will remain.
The Chum Salmon
Salmon species need freshwater courses to spawn. Salmon are remarkable for their ability to return to spawn in the streams where they hatched. On Lyall Creek, a washed-out bridge and the culvert that replaced it prevented chum salmon from returning upstream.
Chum salmon -- weaker swimmers compared with the coho salmon and the cutthroat trout with which they share the stream -- simply couldn't make it past this obstacle. As a result, chum salmon no longer occurred in the creek. The future of Lyall Creek chum salmon might have never had a chance without the efforts of Saturna Islanders.
The culvert was a barrier to adult chum passage.
More than 10 years ago, a small group of volunteers decided to help bring back chum salmon to Lyall Creek. With support from Fisheries and Oceans Canada, volunteers began a program to incubate chum eggs in Lyall Creek and then release the young salmon into the ocean each spring. By 2002, more than 400 salmon were returning to the stream.
Adult salmon returning to spawn naturally in the creek required a helping hand to pass the culvert. Again, the Saturna residents came to the rescue - moving the adult salmon by hand across the impassable culvert.
Parks Canada gets involved
In 2003, the inclusion of the majority of the stream's watershed within Gulf Islands National Park Reserve brought additional technical and financial support to the restoration efforts.
In that year, the Saturna volunteers, Fisheries and Oceans Canada, the British Columbia Ministry of Transportation and Highways and Parks Canada replaced the culvert with a larger and better-designed one, and restored a damaged part of the streambed to a more natural state. As well as being a barrier to fish, the old culvert had also contributed to the accumulation of upstream sediments, largely affecting the nature of the creek's gradient and flow characteristics.
In September 2005, additional in-stream restoration works were completed to restore important structural components and processes to the stream. Root wads and logs were anchored into the banks of the creek and large boulders were placed to create structures which function to increase water quality and improve habitat for all aquatic and riparian species.
Through the efforts of many, this creek is returning to more natural conditions. One has only to take a quick peek at the creek, even during low summer flows, to observe large numbers of juvenile coho and cutthroat trout darting about the gravel. Lyall Creek is now considered to be a bench mark for habitat restoration in the region.
While as a result of past practices, natural habitats were lost on the island, current restoration efforts can now use the Lyall Creek effort as a model of a healthy creek system in the area.