The Coastal Chinook Research and Monitoring Program (CCRMP) conducts research on populations of Chinook salmon on Oregon’s coast. The majority of this work is focused on north migrating populations important to Oregon’s participation in the Pacific Salmon Treaty. Our work includes generating robust adult population estimates for specific basins, estimating harvest of returning adults, and determining appropriate methods and tools to monitor Chinook populations in a cost effective and accurate way.
We currently have projects focused in the Elk, Siletz, Salmon, Nestucca, and Nehalem rivers. We also have staff collecting data in the rivers feeding Tillamook Bay, the Alsea, and the Siuslaw and Umpqua Rivers. Past projects have also examined the Coos, Coquille, and Siuslaw rivers in some detail.
The overall goals of these projects are to improve our ability to estimate adult Chinook salmon spawners from year to year and understand the contribution of Oregon’s stocks to the northern ocean and Oregon fisheries.
Sentinel Stocks Program: Nehalem and Siletz River basins
During the first decade of the 21st century, returns of fall Chinook salmon to the north Oregon coast declined sharply and have now begun to rebound. The Pacific Salmon Commission's Sentinel Stock Program was established to help address some of the issues surrounding fisheries management in identified basins. On the north Oregon Coast, the Nehalem and Siletz were identified as basins requiring additional research to better estimate fall Chinook salmon returns. Our approach has been to conduct mark-recapture experiments in conjunction with a creel survey to develop accurate and precise estimates of spawning escapement and terminal harvest. Results from both the Nehalem and Siletz studies will be used to help generate more accurate and precise estimates for not only these specific indicator stocks, but other production areas within the NOC aggregate. Additional efforts to sample carcasses for scales in both basins will assist in the accuracy of forecasts of the aggregate’s production through the use of sibling regression models which rely on representative sampling of the spawning population.
In addition, visual indices from spawning surveys will be calibrated against the mark-recapture estimates to determine whether any of them track fall Chinook salmon spawner abundance with sufficient precision to form the basis for long-term monitoring and the incorporation of resulting escapement estimates into PSC harvest modeling efforts.
In addition, in the Nehalem basin, we implemented our study with the objective of furthering our understanding of the run timing and population structure of Chinook salmon in the basin. The knowledge and experiences of the local biologists and anglers suggest there are two relatively distinct runs, a summer and a fall run.
Salmon River Exploitation Rate Indicator Stock Implementation
The Salmon River hatchery annually releases approximately 200,000 fall Chinook salmon smolts in the Salmon River on Oregon's north coast. Each fish has been tagged with a coded wire tag to identify the stock from which it originated and had its adipose fin removed. Fish caught in the ocean and terminal fisheries along the West Coast of the U.S. (including Alaska) and Canada are examined for evidence of an adipose fin. Fish missing an adipose fin are sampled for a coded wire tag. Technicians and analysts then identify the stocks from which these fish originate and estimate the harvest rate and distribution of specific stocks of fish. The Salmon River hatchery fish have been identified as an Exploitation Rate Indicator Stock (ERIS) for the Pacific Salmon Commission. The distribution of these fish in fisheries and on the spawning grounds are intended to represent the wild fish produced on Oregon's North Coast inclusive of the Siuslaw north. We annually conduct a creel in the estuary and river fishery and also complete spawning surveys in the basin to recover tags from fish returning to the basin and to estimate the return of both tagged and non-tagged fish. Returns to the hatchery are also examined and sampled for tags.
Improving Chinook salmon fisheries management in Oregon Coastal River Basins
These projects are designed to provide much needed data to improve the management of Chinook salmon fisheries on Oregon’s coast. In recent history, Oregon’s coastal stocks of Chinook salmon have experienced serious declines in abundance. In concert with other funding, the Oregon Department of Fish and Wildlife has developed an approach to fill important knowledge gaps and to improve the accuracy and cost effectiveness of our spawning population estimates. Specifically, this year we will be completing the second year of a mark-recapture experiment and creel on the Nestucca River, collecting scales from spawned fish to estimate age composition in basins where those data are lacking, conducting genetic analyses to determine the distinctiveness of two populations in the Nehalem River, and developing and integrating data collection technology and improving data management. In addition, part of the funding will be used to support our agency’s participation in Pacific Salmon Commission Chinook Technical Committee to develop and improve models and methodologies to better estimate abundance of Chinook contributing to treaty fisheries, to ensure provisions of the treaty are being met related to Oregon stocks, and to address associated conservation needs.
Mid-Oregon Coastal Production Region Coded-Wire Tagging, Recovery and Escapement Estimation of Elk River fall Chinook Salmon
The Oregon Department of Fish and Wildlife (ODFW) considers the Elk River coded wire tag (CWT) Chinook Salmon Program a candidate exploitation rate indicator (ERI) stock for the mid-Oregon coast (MOC) aggregate. Specifically, these funds are being used to hire and outfit three seasonal crew members to conduct creel, spawning surveys, assist with hatchery activities, and to purchase and apply CWT tags to hatchery produced pre-smolts in the spring. The distribution of tagged fish in the ocean and terminal fisheries, at the hatchery, and on the spawning grounds is used to estimate the total number of Chinook salmon that are harvested in various fisheries and that return to the spawning grounds. In addition, these efforts will continue historic data collection used to characterize the Chinook salmon run in the Elk River specifically and in the mid-Oregon coast in general. These data are critical to gathering information on the number and origin of CWT Chinook salmon that return to Elk River between 2010 and 2015. This information will then be used to assess ocean survival and harvest and to evaluate the use of the CWT fish from Elk River as an Exploitation Rate Indicator for the entire mid-Oregon coast. This is an important step in the decision making process to have the mid-Oregon coast adequately represented in Pacific Salmon Treaty fisheries management.
Salmon River CWT comparison (An evaluation of the applicability of a hatchery stock to represent naturally produced stocks as an Exploitation Rate Indicator Stock (ERIS) in the Northern Oregon Coast aggregate) Starting Spring 2012
The 2008 bilateral agreement for the conservation and harvest sharing of Pacific salmon under the jurisdiction of the Pacific Salmon Treaty (PST) specifies the use of coded wire tagging (CWT) programs as the primary data source for managing fisheries covered by the treaty. Management agencies rely on these programs as the primary tool to allocate salmon harvest quotas in commercial, sport and tribal Chinook salmon (Oncorhynchus tshawytscha) fisheries. Oregon’s Salmon River hatchery releases approximately 200,000 adipose marked (Ad) and CWT Chinook salmon smolts annually to serve as the Exploitation Rate Indicator (ERI) stock for the North Oregon Coast (NOC) aggregate. Data collected through this ERI program are critical to the assessment of ocean survival and harvest distribution of Chinook salmon managed through the PST. Questions remain as to whether Chinook salmon reared and released from a hatchery accurately represent naturally produced stocks for management and conservation purposes. Specifically, we are interested in looking for differences in 1) survival rates, 2) overall exploitation rates, 3) age at maturation, and 4) fishery specific exploitation rates between the hatchery and naturally produced stocks. We will also compare the distribution of the ocean harvest between the two stocks. If discrepancies between hatchery and naturally produced stocks are realized, correction factors may be developed to adjust exploitation rates to more accurately reflect rates experiences by wild stocks.