Beyond the Burman: the continuation of a decade-long effort to improve west coast Vancouver Island sac?up escapement estimates

Uu-a-thluk technical staff are building on the success of Roger Dunlop’s Burman River sac?up (Chinook salmon that have reached freshwater) spawning escapement estimate project by expanding his assessment method into the Conuma and Tranquil Rivers, while continuing to empower the next generation of Nuu-chah-nulth fisheries staff in the process.

“We need to have accurate information on abundance. For everything. For conservation, and for fishing plans. That’s all we want – good numbers,” said Dunlop, Uu-a-thluk Northern Region Biologist, when asked about his ongoing project goals.

Dunlop’s original ‘Burman River Chinook escapement project’ was funded by the Pacific Salmon Commission’s (PSC) Sentinel Stocks Program and later the Southern Boundary Restoration and Enhancement Fund. The funding supported sac?up escapement estimates based on innovative mark-recapture programs for almost a decade (2009-2018) in the Burman, Kaouk and Moyeha Rivers.

Over the years, project crew members tagged and recaptured live sac?up, checked carcasses for tags and collected information on the sex, age and origin of the fish.

The goal was to improve escapement estimates for sac?up, and to use the more precise data to improve west coast Vancouver Island (WCVI) Chinook management in southeast Alaska, northern BC and WCVI fisheries.  

Data from the studies showed a relationship between the amount of time sac?up spent on their spawning grounds, or ‘residence time,’ to the first autumn rainfall date. Dunlop termed the relationship between residency time and early rain events the ‘hydrology method.’

The accuracy of this ‘residence time’ value is critical as it is used to take the fish counts from snorkel surveys to estimate the total number of fish that returned to spawn. For the Burman River, Dunlop’s work showed that the methods Fisheries and Oceans Canada was using to estimate sac?up escapements to the Burman River usually resulted in underestimating spawning sac?up.  

Fast forward to 2019, and Dunlop’s ‘hydrology method’ is now being tested in the Conuma and Tranquil Rivers to further confirm its efficacy thanks to the nearly $200,000 in funding received from the PSC’s Southern Boundary Restoration and Enhancement Fund to continue the work.

Crews have been working at both sites since early September, and have resumed the use of radio tags and telemetry (the process of recording and transmitting the readings from the radio tags) for accuracy in their research.

On the Conuma River, Jeffrey Blondeau (Mowachaht/Muchalaht First Nation) is supervising an all-Nuu-chah-nulth crew of five technicians, while Dunlop oversees the work.

Hesquiaht First Nation’s Joshua Charleson is leading a crew of four technicians on the Tranquil River (which includes Uu-a-thluk’s fisheries intern Shelby Huebner) while Jared Dick, Uu-a-thluk Central Region Biologist, provides guidance. 

“It was tough at first,” said Dick, when asked about challenges the Tranquil River crew encountered in the field over the last couple of months.

“We’re bouncing from pool to pool to pool along the river, compared to the Burman and Conuma [rivers] where they’re fishing the same pool every day,” he explained.

Dick was referring to the fact that his colleagues on the Conuma River project have only needed to fish one freshwater stopover pool (that the sac?up were holding in prior to entering their spawning grounds) to mark and recapture fish, while his Tranquil River crew have been forced to haul their boat, net and gear from one pool to another along the river as the sac?up have been holding in three separate pools.

“Each pool requires us having to figure out how to scare the fish to keep them from leaving the net that we close them in,” Dick added. “Each pool requires a little bit of a different strategy.”

Now that the crew have learned the requirements of the Tranquil River, they will place a net at each pool next year which will improve crew fishing efficiency.

Despite the challenges, crews at both project sites have been able to conduct important sac?up escapement estimate research that will produce accurate data to inform individual Nuu-chah-nulth Nations’ fishing plans, and to assist in evaluating whether future conservation initiatives such as ‘Salmon Parks’ are working.

“We will review it [the data] jointly with DFO,” said Dunlop, adding one more way the information will be utilized.

*At press time, Dunlop was applying finishing touches to his ‘’Year 2’ proposal  which has been short-listed for funding by the PSC Southern Boundary Restoration and Enhancement Fund. Dunlop aims to run the project for five years.

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