PROJECT OBJECTIVES

The OASIS project is one of four main ODFW monitoring projects that contribute toward the overall Oregon Plan for Salmon and Watersheds (OPSW or Oregon Plan) monitoring program. The four ODFW monitoring projects are: Western Oregon Rearing Project (Juveniles); Aquatic Inventories Project (Habitat); Salmonid Life-Cycle Monitoring Project (Survival); and the Oregon Adult Salmonid Inventory and Sampling Project (Adults). The habitat, juvenile, and adult monitoring projects are linked through the use of the same GRTS site selection and rotating panel sample design in order to promote sampling efficiencies and allow for integration of data and analysis.

The overall objective of the OASIS project is to monitor status and trends of naturally produced Oregon coastal and lower Columbia salmonid stocks. The project has four main target species; Chinook, Chum, Coho, and Steelhead. Although not a main target species, the project also collects information on spawning Pacific Lamprey. Key metrics include: abundance; spatial distribution; temporal distribution; and proportion of hatchery fish in the naturally spawning population. The geographic scale of abundance estimates varies by species, but the goal in all cases is a point estimate with a confidence interval of +/- 30%.

Spawning ground surveys are conducted from October through January (chinook, chum and coho) and from February through mid-June (steelhead and lamprey). Surveys are conducted at least once every 10 days (chinook, chum and coho) and once every 14 days (steelhead and lamprey). Survey sites are either “Standard” surveys or random GRTS surveys. Standard surveys were specifically selected, many in the 1950’s, for ease of access and historic high numbers of spawning salmon. The GRTS surveys are based on a spatial balanced random selection process, and incorporate a rotating panel design to create a 27 year survey plan. Surveyors either walk up stream or boat downstream, depending of the size of the stream being surveyed. The surveyors count redds, live and dead fish (by species), and sample carcasses for gender, length (mm MEPS), scales, fin clips and tags.

SPECIES OBJECTIVES

Four species of salmonids are monitored through spawning surveys. Primary objectives and geographic scale for each of these species are as follows:

Coho Salmon - (Lower Columbia & Oregon Coast)

• Estimate annual abundance of natural spawners for each population/complex: Lower Columbia - 8 populations (Map); Oregon Coast - 24 populations (Map).
• Survey 30 sites or 30% of the coho spawning habitat in each population.
• Evaluate straying and natural spawning by hatchery fish.
• Map the spatial and temporal distribution of spawners.
• Monitor Threatened and Endangered stocks.
• Monitor and assess abundance trends.
• As need and opportunity allow, research and develop methodologies.

Chinook Salmon - (Lower Columbia)

• Estimate annual abundance of natural spawners for each population: 9 populations
• Survey 30 sites or 30% of the chinook spawning habitat in each population.
• Evaluate straying and natural spawning by hatchery fish.
• Map the spatial and temporal distribution of spawners.
• Monitor Threatened and Endangered stocks.
• Monitor and assess abundance trends.
• As need and opportunity allow, research and develop methodologies.

Chinook Salmon - (Oregon Coast)

•Continue long-term annual estimate of abundance index, (peak count on standard surveys, in fish/mile).
• Monitor and assess trends in abundance index.
• Determine spawner age composition and life history (fish scales).
• Identify hatchery origin fish in naturally spawning population (fin clips and/or marks).
• As need and opportunity allow, research and develop methodologies.

Chum Salmon - (Oregon Coast)

• Continue long-term annual estimate of abundance index, (peak count on standard surveys, in fish/mile).
• Monitor and assess trends in abundance index.
• Determine spawner age composition (fish scales).
• Identify hatchery origin fish in naturally spawning population (fin clips and/or marks).
• As need and opportunity allow, research and develop methodologies.

Steelhead - (Lower Columbia & Oregon Coast)

• Estimate annual abundance of natural spawners for each population/complex: Lower Columbia - 8 populations; Oregon Coast - 6 monitoring areas (Map).
• Evaluate straying and natural spawning by hatchery fish.
• Map the spatial and temporal distribution of spawners.
• Monitor and assess abundance trends.
• As need and opportunity allow, research and develop methodologies.