Lake Cowichan Gazette, October 18, 2010
The weather has turned in the watershed. On Thanksgiving weekend there was some serious rain. Things got very busy at the Department of Fisheries and Ocean’s (DFO) counting fence that spans the Cowichan River below Allenby Road and above the Island Corridor railway bridge.
As September showers became October rain, Catalyst Paper was requested to release enough water at its Lake Cowichan weir to increase river flows from six to 10 cubic meters per second (cms). Then on Thanksgiving Sunday, flows were increased to 20 cms until early Wednesday morning. This pulse of water stimulated salmon to migrate upstream to spawning channels. The Chinook were on the move.
The oldest counting fence that DFO operates is located below Babine Lake and dates back to 1946. On Vancouver Island, the Carnation Creek counting fence has operated since 1970. DFO’s Cowichan watershed fence dates back to 1988. The purpose of our fence is to get an accurate count of the Chinook salmon that migrate up the Cowichan River to spawn. DFO installed it right after Labour Day. In years when fall water levels remain low it remains in place until October 28. The fence is operated under contract with Cowichan Tribes. Crews work on a 24/7 basis. Day shifts are usually the easiest, because the vast majority of the salmon make their way upstream between midnight and 8 a.m.
At the fence site, the river is shallowest by the southern bank of the Cowichan and deepest by the north bank near the shack in the picture. Fence panels are made of closely spaced PVC pipe. Fish are directed to its northern end where they are able to swim through an opening. As they pass through the fence they are videoed, identified, and counted by crew members. On Thanksgiving Sunday, it was really exciting to watch the Chinook start to move in numbers. There goes another, another, another… – It was hard to keep up. Besides salmon, otters and mink occasionally pass through the fence and once in a while, a bear will visit the site. The majority of Chinook salmon that pass through the fence migrate up to an area a few kilometers past Skutz Falls, and spawn anywhere between there and Cowichan Lake. Historically, when numbers were higher, spawning was reported in a number of the tributaries of Cowichan Lake as well.
Accurate assessment of Cowichan Chinook salmon is really important because our Chinook are used as an indicator for the relative strength or weakness of the Lower Strait of Georgia Chinook stocks. Cowichan data is used to manage Chinook fisheries under the Canada-US Pacific Salmon Treaty. Fewer fish making it to their spawning grounds could mean stricter regulations and less fishing.
Unfortunately, numbers of Chinook salmon returning to the Cowichan have been very low, particularly since 2002. Last year, we hit an historical low with only about 540 natural spawning Chinook and 240 available for the hatchery. The annual target for escapement (returning spawners) is 6500 Chinook.
There is a long way to go, but there are some positive signs. First, there are the many volunteers who continue to work on habitat improvement in the watershed. Secondly, it looks like escapement this year should end up being at least double last year’s. Also, the number of two-year Chinook appears to be quite a bit higher this year, indicating that survival at sea is improving. Hopefully this means that next year’s overall run will increase as well.
Rodger Hunter is a member of the Cowichan Lake and River Stewardship Committee (CLRSC), a volunteer group of lake and river residents who are dedicated to the monitoring, protection and rehabilitation of the Cowichan Lake Watershed.ÔÇ»
For more information about the CLRSC, go to their website, online at https://www.cowichan-lake-stewards.ca.
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