Spawning salmon levels rise
Birkenhead River sees highest sockeye return in five years
Nicole Trigg, Special to The Question, Oct.20, 2011
The numbers are in from the Lil’wat Nation’s annual sockeye salmon stock assessment for the Birkenhead River. From the time the sockeye entered the river in late August to shortly after the counting fence was blown out by high water levels towards the end of the run in late September, a total of 193,547 sockeye were counted.
“It would certainly be the largest escapement (population) in the last five years,” said Mike Lapointe, head biologist of the Pacific Salmon Commission (PSC). “The previous largest escapement is 2006, which is 266,000, and since then we had 93,000 in ’07, 19,000 in ’08, 54,000 in ’09 and last year, 128,000.”
Typically, 90 per cent of Fraser River salmon have a four-year lifecycle, but the Birkenhead is different in that there can be significant numbers of five- and six-year-olds as well. This is partly related to the fact that it’s a coastal stream and subject to high flash flooding. Because of these fluctuations in the spawning habitat, the populations have evolved to produce more than one age class.
What this means, said Lapointe, is potentially this year’s higher rate of return is because some of the salmon are from 2006.
“With Fraser sockeye, we talk of parent years as being important since they have a four-year lifecycle, then we’d be looking at the escapement four years ago, which was ’07 and that number was 93,000,” he said. “And so for the Birkenhead, it looks like this parent year has produced fairly well.”
But he won’t know how many have returned in 2011 as five-year-olds from the abundant 2006 brood until he examines the samples, said Lapointe.
The Mount Currie Fisheries Program works closely with the PSC throughout the year, closely monitoring conditions of the fish and river.
“Because this is the territory we’ve grown up in and we’re very responsible for, we also document environmental information like temperatures, differences we see in the river and things that catch our eye,” said Maxine Joseph-Bruce, fisheries program manager for the Mount Currie Band.
The collected data is sent to the PSC along with samples — a combination of scales and otolith, the ear bone in the fish. Both have rings on them for determining age, very much like rings that you could see on a tree, said Lapointe.
The annual sockeye count requires the installation of a counting fence across the Birkenhead to create a four-foot wide opening the salmon can pass through. Narrowing the river in this manner facilitates tracking the number of fish swimming upstream.
“We situate a working platform just up-river, about eight feet from the opening, and we count every single fish that swims through that gate,” said Joseph-Bruce.
This year, the counting bench was staffed by two people 24 hours a day, seven days a week — in eight hour shifts — from Aug. 31 through to Sept. 23, when the fence had to be removed due to heavy rain and clogging caused by fallen leaves.
“Kids visit from the local schools, Signal Hill and Xit’olacw, a number of tourists stop in, plus it’s a really positive approach to education and awareness about salmon in our valley,” said Joseph-Bruce. “Some people don’t have a clue that sockeye are returning to the Birkenhead.”
Lapointe added, “The program that Maxine is running is just such a terrific example of the co-management that can occur with the Department of Fisheries and Oceans in terms of having folks that live in the area do the assessments.”
Joseph-Bruce recently attended a salmon ceremony at Pemberton Secondary School and said she would like to see such appreciation for the Birkenhead salmon spread to all local communities.
“They’re aware of this beautiful animal that comes back here… I’m really proud of our youth who are paying attention, and how we in this valley are pretty lucky our land gets fed by these wonderful salmon that return back,” said Joseph-Bruce.
