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.
Adult Chinook returning to the Cowichan River have been enumerated using a counting fence since 1988 as a PSC indicator stock. The operation of the fence has been met with various technical/environmental challenges over the years resulting in site relocation as well as several re-builds. Cowichan Tribes has expressed concern regarding negative impacts to fish including migration delays and physical damage. This proposal will investigate the use of PIT tags as an alternative method for estimating escapement. Specifically, tags returning from juvenile deployments will be expanded based on a mark rate from a sub-sample of the population. PSC funding will be used to both deploy tags in juveniles as well as to support an estimate of mark rate in the adult population.
The use of PIT tags will also allow additional information to be collected including downstream survival of juveniles, marine survival estimates, age class composition and migration time. Additionally, predation investigations may also be supported as PIT tags have been detected inside other animals and in scat within the surrounding area.
S19-I42 Cowichan Adult Chinook Enumeration Methodology Change 2019 Report
S18-VHP27 Cowichan Adult Chinook Enumeration Methodology Change
This project will support DNA analysis of samples collected in the Victoria area fishery. The objective is to estimate stock composition of the catch of chinook salmon in the Victoria area sport fishery with a specific focus on estimating fishery related mortality in this fishery of spring and summer 52 chinook returning to the Fraser River as well as other chinook stocks of concern such as Nooksack.
This project consists of 1) additional sampling effort within the existing creel survey to increase probability of achieving a minimum 100 DNA samples per month from April-September, and 2) DNA lab analysis of the tissue sample, and 3) reporting to the Pacific Salmon Commission’s Southern Fund and fishery stakeholders. A priority is placed on June and July sampling coinciding with peak migration timing of spring and summer 52 Fraser chinook – but sampling May to August will be addressed in this proposal.
Note there are no CWT indicators for the Fraser spring and summer 52 chinook. Since exploitation is primarily in the Fraser and Juan de Fuca, the exploitation can be approximated using the run reconstruction of Fraser River chinook salmon, which provides estimates of total return to the mouth of the Fraser. Information related to mortality of other stock groups may also be used in chinook FRAM and in Southern Resident Killer Whale conservation.
This project will support DNA analysis of chinook samples collected in the Strait of Georgia area recreational fishery. The objective is to estimate fishery related mortality and exploitation rate of spring and summer 52 chinook returning to the Fraser River as well as other stocks. Sampling in the existing creel survey and by a group of 30+ ‘Avid Anglers’ will ensure adequate sample sizes. This project is incremental to the DNA sampling proposed separately for the Victoria area / Juan de Fuca and will assess the level of harvest and so exploitation of this Fraser chinook stock group in the approach through the Strait of Georgia relative to the exploitation in the Strait of Juan de Fuca.
Historic CWT from Dome Creek (spring 5/2) suggest the majority of this stock group approaches through Juan de Fuca. The last of the Dome Creek CWT was over 10 years ago and there is significant debate on the impact of approach fisheries on this and other stocks of concern. This project will provide more up to date information on relative fishery impacts. If the exploitation is minor then estimation of the exploitation using the Fraser chinook run reconstruction (provides the abundance to the mouth of the Fraser) plus the Juan de Fuca fishery may be sufficient as an indicator stock (that is assume a constant small percentage from all other marine fisheries).
The stock composition estimates from this project will also support conservation of chinook as critical habitat for southern resident killer whales.
S18-VHP16 Estimation of stock composition of Chinook fisheries in the Strait of Georgia and Juan de Fuca Strait
The main objective of this study is to evaluate metrics of growth in otolith samples of natural origin recruits (NOR) to test the hypothesis that early freshwater growth of Hanford Reach Fall Chinook salmon is related to adult spawner and/or subsequent juvenile abundance (density dependent effects). The proposed project will determine whether the prior year adult escapement and/or pre-smolt abundance of juvenile fall Chinook salmon in the Hanford Reach is related to early freshwater growth in these fish.
N18-VHP17 Upriver Bright Density Dependence: Analyses of Existing Samples Report
The goal of the project is to estimate the spawning escapement of the Fraser River – South Thompson age 0.3 aggregate (ST0.3A Chinook). The ST0.3A escapement will be estimated using Coded Wire Tags (CWT), Genetic Stock Identification (GSI), and CWT exploitation rate indicator stock data from escapement and Fraser River fisheries. To achieve this objective, we will increase recovery of CWTs from Chinook carcasses in the Lower Shuswap River; conduct a high-precision mark-recapture project and CWT sampling in the Middle Shuswap River; collect age samples across the South Thompson watershed; produce a CWT release group of Middle Shuswap River smolts (to augment the Lower Shuswap indicator stock); and analyze GSI and age data from the Albion Test Fishery.
N18-VHP16 Estimation of 2015 – 2018 Escapements of the South Thompson 0.3 Chinook Aggregate using a Bayesian Model that Combines Data on CWT Recoveries and GSI_Report Title Page
A mark-recapture project would be conducted to estimate escapement and would involve capturing and marking live fish as they migrate to the spawning grounds and recovering carcasses. The Coded Wire Tag (CWT) smolt group is required to continue representation of Lower Shuswap River (and Fraser River Summer 0.3) Chinook in subsequent fisheries and escapement. This project includes capture of brood stock, rearing of like-timed and like-sized 0+ smolts, and purchase and application of 100,000 CWTs to those hatchery smolts, as part of the overall release group.
The data acquired from the application of CWT’s aids in the computation of the exploitation rate data that are used for several purposes, including estimation of maturation rates, reconstruction of production for stock-recruitment analysis, monitoring Individual Stock Based Management (ISBM) fishery obligations (specified in the 2009 Agreement), development of agency forecasts for the PSC Chinook model calibration, and providing an independent verification of the PSC Chinook model representation of fisheries, stock dynamics, and stock distribution among fisheries and escapement.
In particular, the Fraser River Summer-run Age 0.3 Chinook Stock (South Thompson aggregate including the Lower Shuswap) is one of the largest contributors to Southeast Alaska (SEAK) and Northern BC (NBC) fisheries, as well as recreational and First Nations harvests in the ocean and freshwater. Because of this fact, high quality, accurate escapement estimates are required to accurately forecast the NBC and SEAK AABM abundance indices. Recently, the CTC and PSC have expressed concerns about the performance of the Chinook Model, especially for northern fisheries, and this project will ensure availability of quality escapement and maturation rate data for one of the largest stocks.
Data acquired through the Lower Taku River commercial and assessment fisheries are vital elements of the Taku River fishery management and stock assessment programs. Sampling involves the inspection for and recovery of coded-wire tag (CWT) information from Chinook and coho salmon which is used in the estimation of smolt production, the inspection for and recovery of spaghetti tags from Chinook, sockeye, and coho to support abundance metrics, the collection of otoliths from sockeye to estimate contributions of enhanced sockeye salmon, and the collection of age, sex, and length samples from Chinook, sockeye and coho salmon caught in the fisheries. These baseline stock assessment data are used for stock recruitment analyses, preseason forecasting programs for Chinook and sockeye salmon, and monitoring stock health.
N19-I24 Taku River Canadian Commercial Fishery Sampling & Stock Assessment 2019 Report
N18-VHP07 Taku River CDN Comercial Fishery Sampling and Stock Assessment Report 2018
NF17-VHP11. Taku Fishery Sampling & Stock Assessment - Final
Data acquired through sampling of the Lower Stikine River Canadian commercial and assessment fisheries are central elements of the Stikine River fishery management and stock assessment programs. Sampling involves the inspection for and recovery of coded-wire tag (CWT) information which is used in the estimation of smolt production of Chinook and coho salmon, the inspection for and recovery of spaghetti tags from Chinook to support abundance metrics, the collection of otoliths from sockeye to estimate contributions of enhanced sockeye salmon, the collection of egg diameter data to determine the contribution of Tahltan Lake sockeye salmon, and the collection of age, sex, and length samples from Chinook, sockeye and coho salmon caught in the fisheries. These baseline stock assessment data are used for stock recruitment analyses, preseason forecasting programs for Chinook and sockeye salmon, and monitoring stock health.
N19-I16 Stikine River Canadian Commercial Fishery Sampling and Stock Assessment 2019 Report
N18-VHP05 Stikine River Canadian Commercial Fishery Sampling and Stock Assessment Report 2018
N17-VHP10 Stikine River Fishery Sampling and Stock Assessment
U.S. fisheries in Southeast Alaska (SEAK) harvest stocks of Chinook salmon bound for river systems in Alaska, Canada, and the continental U.S. Thus, fisheries in SEAK are managed under the purview of the Pacific Salmon Treaty (PST), in which an abundance-based management framework is used for Chinook fisheries. This requires management to have access to reliable information on stock-specific catch, escapement, and recruitment to forecast indices of abundance in PST fisheries.
This project aims to improve fishery management and provide independent estimates of stock composition in commercial troll and sport Chinook salmon fisheries in Southeast Alaska. Further, the project will take the analysis beyond basic estimation of stock composition by combining genetic assignment of individuals from selected stocks and fisheries with their associated age and mark information to provide additional information about Chinook salmon in SEAK fisheries for Chinook Technical Committee needs. This type of information has been used to measure the effectiveness of management actions in SEAK as well as to contribute to applications outside of SEAK (e.g. estimating age-specific terminal returns of stock groups and forecasting returning run sizes). This project is an integral part of a larger SEAK genetic stock identification program for Chinook salmon, which includes comprehensive coverage of major gillnet, troll, and sport fisheries.
N17-VHP07 Origins of Chinook harvested in SEAK fisheries Report 2017