Category: 2019

Taku River – Chinook Headwater Sampling

The purpose of this project is conduct mark-recapture Event II (i.e. recapture) sampling on various Taku headwater streams, both established locations (i.e. Tatsatua Creek, Tseta Creek, Nahlin River and Dudidontu River) as well as exploratory areas (i.e. Sloko River). These sites are the major contributors of samples and tag recoveries to the estimation of drainage-wide Taku River Chinook salmon abundance. Sampling will be conducted by Fisheries and Oceans Canada (DFO) in collaboration with the Taku River Tlingit First Nation (TRTFN) and Alaska Department of Fish and Game (ADF&G). This tag recovery and sampling is a critical element of the Event II component of the Taku River Chinook salmon mark-recapture program, provides coded-wire tag (CWT) recoveries to estimate smolt survival and marine survival (in concert with other bilateral projects), and provides data essential for forecasting and monitoring the health of Taku River Chinook salmon stocks.

The bulk of this project is tag recovery and biological sampling for Chinook salmon on Tatsatua Creek (in the vicinity of Little Tatsamenie Lake), a long standing DFO project which contributes more than 25% of the total Taku River Chinook salmon tag recoveries, and many CWT recoveries in recent years. This component has been funded by the NEF in recent years as part of a different proposal. The remainder of the project will allow DFO and TRTFN staff to fully participate with ADF&G on other Taku River Chinook headwater sampling projects at other established sampling sites which also provide a significant recovery and sampling contribution to the Taku River Chinook mark-recapture and CWT programs.

Estimating Aggregate Coho Salmon Escapement to the Lower Fraser Management Unit

The absence of reliable escapement estimates for Coho Salmon in the Lower Fraser River (LFC) MU and its three component Conservation Units (Lillooet, Lower Fraser A, and Lower Fraser B collectively discussed as LFC in this proposal) represents a critical information gap for Southern Boundary Coho Salmon Management.

This proposal addresses this concern by proposing an approach that eliminates the need to access hard-to-reach watersheds, reduces the need for visual escapement surveys from several to only the Nicomen Slough and Upper Lillooet River, and leverages existing infrastructure (hatcheries), processes (Coded Wire Tagging (CWT) and otolith tagging) and projects (monitoring of recreational and Food, Social and Ceremonial harvests, Lillooet sonar imaging (ARIS), and Nicomen Coho CWT, Chilliwack hatchery juvenile rearing and adult counts) with advanced technologies (PIT, radio tags, GSI) and a test fishery.

We propose to estimate total LFC escapement through the expansion of stock composition ratio data gathered at a test fishery. A new test fishery will sample the Fraser Coho migration, and a random, representative sample of Coho will have DNA, CWT and otolith samples taken to estimate stock composition ratios.

Transboundary Rivers Otolith Thermal Mark Recovery

Enhanced sockeye salmon outplanted as part of enhancement projects in the Transboundary Rivers area have their otoliths thermally marked as fry to allow later identification to stocking origin and brood year. Transboundary Rivers (TBR) stock assessment and monitoring projects collect otoliths from both outmigrating sockeye smolts and returning sockeye adults through a variety of projects. The proposed thermal mark recovery project will fund the preparation, interpretation and analysis of these samples, which will provide critical data to stock assessment and enhancement activities; wild/enhanced ratios, scale aging validation, fry to smolt survival, smolt to adult survival, contributions of enhanced fish to returns, straying rates, etc. These data are vital elements of Transboundary stock assessment, enhancement, and fishery management programs. Data are used in enhancement planning and evaluation for multiple stocks, forecasting of returns, annual run reconstructions, and monitoring fishery management performance.

Taku River Sockeye Salmon Telemetry

The purpose of this project is to augment the ongoing Taku Fishery Sampling and Stock Assessment in support of management as outlined in Chapter 1 of the Pacific Salmon Treaty. The Taku River sockeye salmon stock assessment project has been conducted annually since 1984 and is a cooperative effort between the Alaska Department of Fish and Game (ADF&G), Department of Fisheries and Oceans Canada (DFO), and the Taku River Tlingit First Nation (TRTFN). The objectives of this stock assessment are to provide inseason and postseason estimates of inriver abundance and to document biological characteristics (migratory timing, migratory rates, and age, sex, and size composition) of Taku River sockeye salmon stocks. Spaghetti tagged-to-untagged ratios of salmon harvested in the Canadian inriver gillnet fisheries are used to develop mark-recapture estimates of the inriver abundance of sockeye salmon.

Taku River Sockeye Salmon Genetic Stock Identification Analysis for Commercial Samples

This proposal involves genetic analysis of tissue samples anticipated from the in-river commercial sockeye fishery on the Taku River. This activity was first supported by the Northern Fund in 2008 and makes use of the baseline samples collected with Northern Fund assistance from 2007-12.

This will identify the composition of the commercial harvest by stock groupings. In addition, when coupled with escapement counts from headwater counting fences (weirs), it will permit estimation of drainage-wide abundance for comparison with the mark-recapture estimate or other assessment methodology.


Development of Stikine River Coho Salmon Stock Assessment Options

The primary objective of this project is to test methodologies for enumerating three select components of the Stikine River coho population, specifically the Iskut River, Chutine River, and Katete River stocks.

The Pacific Salmon Treaty agreement requires development of new abundance-based management regimes for Stikine River coho salmon. A central requirement of an abundance-based management program is the development of defensible abundance estimates; ideally stock specific abundance and run timing. Besides being of value as indices, reliable abundance estimates for specific stocks have the potential to be used to estimate drainage-wide abundance using a genetic stock identification (GSI) ratiobased approach, once a Stikine River coho salmon baseline has been established.

Stikine River Chinook Salmon Mark-Recapture Program

The enumeration of Stikine River Chinook salmon is a critical component of abundance based management mandated by the Pacific Salmon Treaty. A key element of the enumeration is ongoing mark-recapture estimation based on application of tags to returning Chinook and the recovery of these tags in in-river fisheries, at enumeration facilities, and on spawning grounds. Event I of the mark recapture is the application of tags through a scientific live capture drift net program near Kakwan Point, Alaska, on the Stikine River operated jointly by Alaska Department of Fish and Game (ADF&G), Fisheries and Oceans Canada (DFO), and the Tahltan First Nation (TFN). This project covers a majority of Chinook salmon migration into the lower Stikine River at Kakwan, and applies spaghetti tags to as many returning fish as possible through two crews drift netting a minimum of 4 wet hours per day each day. This proposal seeks funding to support the DFO/TFN drift crew for the duration of Event I. Tag recoveries from spawning grounds are critical components of the mark-recapture project and this proposal also seeks funding to support a week of post-spawn sample collection and tag recovery field work at the Verrett River, a Stikine River indicator stock.

Chinook salmon genetic baseline update for Southeast Alaska and Canadian AABM fisheries

Southeast Alaska (SEAK) and Canadian aggregate abundance-based management (AABM) fisheries harvest Chinook salmon originating from throughout Southeast Alaska, Canada, and the southern U.S.  This diverse mixture of migrating stocks requires a comprehensive coastwide genetic baseline to accurately estimate the stock composition of harvests. The overall goal of this project is to use a phased approach to develop a coastwide Chinook salmon single nucleotide polymorphisms (SNPs) baseline to estimate the stock composition of harvests in SEAK and Canadian AABM fisheries.

The two biggest hurdles to assembling a coastwide Chinook salmon SNP baseline are: 1) no single agency has all of the baseline tissue or DNA samples necessary to adequately represent coastwide Chinook salmon production, and 2) different agencies do not all necessarily use the same SNP panels. To address these hurdles, we have worked with collaborators at the University of Washington (UW) to compile lists of SNP markers and populations screened by agency and university labs from Canada and the U.S.

Video enumeration for sockeye into Kuthai and King Salmon Lakes

TRT Fisheries conducts long term adult sockeye enumeration weirs at Kuthai and King Salmon Lakes. Due to shallow water at both lake outlets, and resulting bear activity, there was an interest in trying to improve the efficiency of moving fish thru these weirs. In 2018, the Deparment of Fisheries and Oceans (DFO) provided video and power systems for trial video enumeration. This appeared to work very well, however the equipment has to be returned for DFO use next year. Therefore, it is proposed that TRT Fisheries would purchase the necessary video and power equipment to continue weir enumeration in this manner. Such will facilitate improved passage while minimizing fish handling.

Skeena River Aggregate Coho Salmon Escapement Estimator

Northern coho stocks, including Skeena River coho, are harvested in commercial, recreational and Aboriginal fisheries in Canada and Alaska. Establishing robust stock assessment programs for coho is important for maintaining future coho fisheries.
By comparing the relative proportions of populations of known abundance with those that are not consistently enumerated, we can develop an escapement estimate for the aggregate stock. Furthermore, increasing the number of populations in the SNP baseline will increase genetic resolution for coho, and allow us to identify the populations of origin with higher precision for coho captured in mixed-stock fisheries in Canada and the U.S. When used in conjunction with an abundance estimate of a specific coho population within the Skeena River aggregate, an upgraded genetic baseline will improve estimates of exploitation rates in mixed-stock fisheries and therefore further support informed decisions by fisheries management.