In previous years, Columbia River Inter-Tribal Fish Commission has been funded to expand the genetic baseline for Chinook salmon with microsatellite markers and more recently single nucleotide polymorphisms (SNP) markers. While this has provided moderate improvement to baselines used for genetic stock identification (GSI), new technology is available that allows for vastly increasing the number of SNPs that can be added to baseline populations. This new technology uses an approach called Restriction-site Associated DNA (RAD) tags to genotype thousands of SNPs in baseline samples. This should provide a nearly unlimited number of powerful markers for GSI purposes and greatly improve the resolution and accuracy of mixed stock analyses.
Concern for West Coast Vancouver Island (WCVI) natural Chinook currently limits PSC fisheries in Southeast Alaska, the Haida Gwaii recreational fishery and particularly the Area F troll fishery in northern British Columbia and troll fisheries and some recreational fisheries on the WCVI. Although the Burman River is enhanced, the population is of sufficient size to estimate the escapement with precision, and thermally marked otolith sampling provides an estimate of the naturally spawned fraction.
The program will estimate the escapement of adult Chinook salmon to the Burman River, a PSC Chinook escapement indicator, using both closed population and open population mark-recapture techniques refined between 2009-2014. The project will also quantify age, sex and origin compositions. Estimates of abundance of the thermally marked hatchery fraction combined with a precise escapement estimate will provide important information to verify and support the WCVI Aggregate ratio estimation project by providing an independent reference point (the Burman River Chinook hatchery fraction, independent of Robertson Creek Hatchery stock) in the northern WCVI area.
The Kitwanga River is a biologically rich tributary of the Skeena River that produces a significant portion of the overall Skeena salmon that return each year. Kitwanga River sockeye are of significant importance because they are genetically unique, and Gitanyow Lake, in the Kitwanga watershed, is one of the ten largest sockeye producing lakes in the Skeena Watershed. Kitwanga sockeye are also considered a conservation unit as defined in Canada’s Wild Salmon Policy. Historically, Kitwanga sockeye numbered in the tens of thousands, but due to drastic declines in abundance, Kitwanga sockeye are no longer directly fished commercially or harvested for Food, Social and Ceremonial purposes.
The enumeration of Kitwanga sockeye has been ongoing since 2000, first through the operation of a temporary fence in the upper part of the watershed, and then through the operation of the Kitwanga River Salmon Enumeration Facility (KSEF) located near the mouth of the Kitwanga River. The KSEF has been in operation for the last 12 years and has proven to be an extremely important in-season/post-season fisheries management tool. Despite this, no long-term funding has been secured to operate the KSEF on a yearly basis. In the past few years, the cost to operate the facility has been variously shared by the Gitanyow Fisheries Authority, Fisheries and Oceans Canada, Pacific Salmon Commission, Pacific Salmon Foundation and Skeena Wild Conservation Trust.
Provisions of the Pacific Salmon Treaty specify harvest sharing arrangements of Nass and Skeena River sockeye salmon returns for the U.S. and Canada. The United States is allowed to harvest a fixed percentage of the Annual Allowable Harvest of Nass and Skeena sockeye stocks in Alaska’s District 101 gillnet and District 104 purse seine fisheries. Accurate estimates of the stock-specific catch in commercial fisheries of each nation are required to estimate the total return of these stocks and the percentage of each stock caught in treaty-limited fisheries. Annual catches over or under the agreed percentage are made up for in subsequent years.
Until recently, the Alaska Department of Fish and Game (ADF&G) used scale pattern analysis successfully to estimate contributions of Nass, Skeena and Southeast Alaska sockeye stocks to fisheries in southern Southeast Alaska. Since 2006, the Auke Bay Laboratories has used genetic analysis for the Northern Boundary sockeye fisheries. Results from comparisons between stock composition using scales and genetic analysis show both methods provide accurate estimates of stock composition, although DNA analysis is able to discriminate stocks at a finer resolution than scales. An additional advantage of the DNA technique is that it does not require annual sampling to re-establish the escapement baseline.
The purpose of this project is to continue the genetic stock identification of the commercial sockeye catch in ADF&G District 101 gillnet fishery and District 104 seine fishery using the baselines developed by the ADF&G.
NF-2008-I-30 Guthrie (Guyon)
NF-2007-I-19 Wilmot (Guthrie)
NF-2006-I-12 A Wilmot (Guthrie)
We propose to use hydroacoustic methodology combined with trawl and gillnet sampling to estimate the limnetic fish species composition in six Skeena River and Nass River watersheds lakes and to estimate the population and rearing densities of age-0 sockeye fry and competitor limnetic species at each surveyed lake. The sockeye trawl and gillnet samples will also provide age and size data for the juvenile sockeye population at each lake.
Sockeye originating from the selected lakes are harvested in both Canadian and American fisheries, and thus relevant to the Pacific Salmon Treaty. Hydroacoustic surveys are a cost effective method for assessing the status of sockeye stocks. Adult escapements for many BC north coast sockeye lakes are currently not determined due to high costs from the remoteness of the lake or due to other factors such as poor visibility for assessing lake spawners. The hydroacoustic methodology allows for a quick and accurate assessment of the stock status of each surveyed lake. For lakes where reliable estimates of adult escapement are available, hydroacoustic fry surveys are useful for quantifying spawner-to-fry productivity. Finally, the estimates of age-0 sockeye fry population can be compared to the lake carrying capacity for each lake.
Weir counts have been made on the Klukshu River, part of the Alsek River system, by the Department of Fisheries and Oceans (DFO) in co-operation with the Champagne-Aishihik First Nation, since 1976. A mark-and-recapture program ran from 2000 to 2004, and in 2005 and 2006, the Alsek sockeye population was estimated using tissue sample and catch information from the commercial sockeye fishery in Dry Bay as well as the weir counts. By recommendation by the Northern Fund Committee in 2008, a statistically valid sampling strategy that would provide the foundation for reconstructing sockeye and Chinook returns to the Alsek River was completed. Based on this model, it was proposed that funding be provided to analyze sockeye tissue samples collected in the commercial sockeye fishery in Dry Bay (up to 750 per season), to reconstruct the Alsek sockeye runs as described in Gazey’s analysis.
Coho salmon returning to the Taku River pass through an offshore troll fishery before entering inside waters where they encounter seine, drift gillnet, and recreational fisheries. After entering the river, the remaining coho salmon encounter drift/set gillnet fisheries in Canada. Such a resource is worthy of a stock assessment program that directly estimates production parameters such as harvest, escapement, exploitation rate, smolt production, survival rates and brood year production. This project will provide annual estimates of escapement necessary to refine escapement goals and forecast runs. Improved escapement goals and run forecasts along with inseason abundance estimates allow implementation of abundance-based management. These combined efforts in-river along with adult sampling programs in the various marine fisheries allow detailed stock assessment analyses.
Funding of this proposal will augment the existing joint Canada and US coded wire tagging programme and serve to provide the resources to meet the Stikine River chinook and coho salmon smolts tagging objectives. The data derived will be used to determine the distribution, run timing, marine survival, and magnitude of marine catches of adult Stikine River chinook salmon, and distribution and run timing adult Stikine River coho salmon. This project is directly linked to the requirement in Annex IV, Chapter 1, paragraph 3(a)(2&3) of the PST to develop and implement abundance-based management regimes for Stikine chinook and coho salmon.
NF-2015-I-3 Etherton (Boyce)
Stoltz Bluff is a deposit of glacial sediment that extends for approximately 600 m at the outside of a natural meander bend on the Cowichan River, 27 km upstream of Cowichan Bay. Stoltz Bluff was previously identified as the largest point source of fine sediment on the river, representing on average 35-45% of the river’s annual total suspended sediment (TSS) load (KWL Assoc. Ltd. 2005). This is significant in that effective sediment management was identified as the second highest fish habitat restoration priority in the Cowichan Recovery Plan, prepared for Cowichan Tribes’ Treaty Office (LGL Ltd. 2005).
The primary objective of a potential Stoltz Bluff remediation project evolved over 25 years to become “the effective control of massive sediment transport from the bluff (i.e., 10,000-28,000 m3/year since 1993) (KWL Associates Ltd. 2005)), that had been negatively affecting Cowichan River fish habitats and stocks for many kilometres downstream (Burt and Ellis 2006).” The recent Cowichan River Watershed Health and Chinook Initiative (Ayers 2017) reemphasized the value of improved year-round water quality and salmonid spawning habitat as an ongoing strategic management objective.
Beginning in July 2006, the BC Conservation Foundation (BCCF) coordinated a major sediment remediation project at Stoltz Bluff. Work included construction of an engineered 600 m rip-rap berm and terrace, complete with a series of weirs, channel gradient controls and bioengineering treatments designed to move river flows away from the base of the bluff and prevent further bank erosion and major slope failures.
The initial phase of the project took 10 weeks to build, and was supported by a group of seven partners who contributed $830K in funds and in-kind construction materials (including $250K from PSC). For 10 years following the project’s inception, there was a significant improvement in the river’s water quality (i.e., TSS and turbidity) and downstream fish habitats (Gaboury et al. 2012), which is thought to have contributed to incremental gains in annual returns of the river’s fall Chinook and chum salmon stocks, as well as winter steelhead.
However, since 2014, there has been a notable (and even dramatic) change in slope stability at Stoltz Bluff, apparently prompted by the cyclical return of wetter winter weather conditions (McQuarrie 2017). Mass wasting events in the Bluff’s gullies and numerous smaller slope failures have collectively overwhelmed existing sediment retention infrastructure, resulting in higher sediment loads entering the Cowichan River. If this is not effectively mitigated in subsequent annual maintenance activities, a decade of improved spawning conditions will likely become incrementally reversed.