Tag Archives: chum

Automating procedures for the forecasting of terminal run and escapement of Chinook, coho and chum salmon stocks using open-source statistical software

The annual exercise of forecasting terminal run or escapement is a critical aspect of management and conservation of salmonids coastwide. This project involves the completion of an automated computer program (henceforth called “ForecastR”) relying on the open-source statistical software R to generate age-specific forecasts using a variety of generic models including (i) simple and complex sibling regressions with the ability to include environmental covariates, (ii) time series models such as ARIMA, exponential smoothing, and naïve models, and (iii) mechanistic models such as average return rate models that depend on auxiliary data such as the number of outmigrant juveniles, the number of hatchery fish released or the number of spawners.


Albion-based Estimate of Total Fraser River Chum Escapement Using GSI and Estimate of Chilliwack River Chum Escapement

We propose to enumerate total Fraser River chum salmon escapement by conducting a high precision enumeration project on Chilliwack River escapement (e.g. mark-recapture or DIDSON) and combining the result with the ratio of Chilliwack chum to the total Fraser chum captured in the Albion test fishery. The proportion of Chilliwack chum at Albion will be determined using GSI on tissue from scale samples already collected during the test fishery.
This project will improve our ability to provide accurate spawning escapement estimates for Fraser River chum salmon. Accurate estimates are important to all aspects of Fraser River chum salmon management including annual stock run reconstruction, production forecasting, in-season terminal abundance estimates, the evaluation of management decisions/actions, and harvest sharing.


Northern Boundary Area Summer Chum Salmon Monitoring

The purpose of this project is to improve assessment of summer chum salmon escapements in the northern boundary area of southern Southeast Alaska. The Alaska Department of Fish and Game currently maintains an escapement index of 13 summer-run chum salmon streams in the Boundary Area that are assessed primarily through aerial survey methods. Two additional index streams were identified during the first two years of this project, including one that was suitable for conducting long-term foot and aerial surveys. These streams were added to the Southern Southeast Subregion summer chum salmon escapement index during the Alaska Board of Fisheries meeting in February 2015. ADF&G Commercial Fisheries managers have expressed concern regarding their ability to obtain reliable counts of chum salmon in some of the large mainland rivers where chum salmon may be masked by high densities of pink salmon, particularly in years of low chum salmon abundance. The primary objective of this project is to conduct helicopter surveys of summer chum salmon on currently monitored, large mainland river systems south of Wrangell and one new index stream on Prince of Wales Island. Helicopter surveys will provide surveyors improved views of these streams, validate observations of chum and pink salmon abundance, identify primary chum salmon spawning areas, and improve managers’ ability to identify chum salmon during routine aerial surveys of other index streams in the area. Additional foot and aerial surveys conducted concurrently on three smaller chum salmon index systems will similarly allow for direct comparison to aerial survey estimates. Results from these surveys will guide future chum salmon monitoring in the boundary area. In addition, we will opportunistically collect tissue samples from pink and chum salmon for Southeast Alaska genetic baselines as needed.


Benchmarks of biological status for data-limited populations of Chum Salmon in southern BC

The Pacific Salmon Treaty (PST) Chum Annex requires biological benchmarks to inform the development of fishery reference points for PST related fisheries, including the lower fishery reference point for the Johnstone Strait fisheries as well as subsequent terminal fisheries. Biological benchmarks for data-limited populations have been proposed and are currently being applied to Conservation Units (CUs), or population units, of chum salmon in southern BC. The first phase of this project evaluated percentile-based benchmarks for data-limited CUs of chum salmon on the Inner South Coast of BC. Our preliminary results suggest that the 25th percentile lower benchmark is more precautionary than the stock-recruitment based lower benchmarks developed under Canada’s Wild Salmon Policy, except when CU productivity is low and historical harvest rates are high.
For 2016, we will expand our evaluation of percentile-based benchmarks to include the west coast of Vancouver Island and Fraser River, and expand our use of assessment models to include hierarchical multi-CU models. Finally, we will provide recommendations on the application of benchmarks to chum management units (through component CUs within management units) and chum salmon Genetic Units, as identified by a project funded by the PSC SEF on genetic stock identification, on the west coast of Vancouver Island and in the Fraser River within the context of the PST Chum Annex.


Refining & standardizing Nass area chum salmon stock assessment 2014

Current methodology for estimating escapement and run size of Nass Area Chum salmon relies on a number of untested assumptions, resulting in considerable uncertainty regarding stock status. We propose a detailed review of recent and historical escapement data for Nass Area Chum salmon stocks, combined with strategically targeted escapement surveys, to refine and standardize the methodology used to calculate Nass Area Chum salmon escapement and run size.