Home > About this report > How we measure

How we Measure

Charting a course to recovery

Measuring the numbers of fish, the health of their habitats, and recovery plan implementation gives us tools to determine how well salmon are recovering.

At the scale of the recovery region, data is used to adaptively manage so that the recovery plans are implemented most effectively. At the state scale, data is used to inform harvest, hatchery, and habitat management.

The high level indicators in the list below were adopted in 2009 by the state Forum on Monitoring Salmon Recovery and Watershed Health and today still provide information that is used to tell us how we are doing and whether we need to adjust recovery plan implementation. This 2018 report contains information about most of these indicators.


Adult spawners
Adults harvested
Juvenile out-migrants (smolts)

Watershed Health

Land use and land cover
Biological health (in-stream)
Stream physical habitat
Riparian condition
Water quality
Water quantity (stream flow)

Implementation Indicators

Plan implementation progress
Barriers to fish passage
Hatchery practices meeting scientific standards

Adult Abundance (Adult Spawners) — What does this indicator mean?

The State of Salmon in Watersheds reports on specific changes over time in the numbers of fish, as well as a broader summary about how each species is doing overall. Each region has several charts that display abundance of the fish populations. “Abundance” represents the number of fish returning to spawn (either total number of fish spawning naturally or number of wild-born fish spawning naturally). The type of abundance data available and used for evaluation depends on several factors, including the ability to distinguish between hatchery-origin and natural-origin (wild) fish on spawning grounds. In most cases, the fish that are counted toward recovery goals are wild spawners.

Abundance is one key piece of information the National Oceanic and Atmospheric Administration (NOAA) uses to evaluate salmon recovery status. Additional attributes for evaluating population status that are not reported here include productivity, life history, genetic diversity, and the spatial structure of the populations (i.e. where and when fish migrate and spawn). NOAA also considers threats and factors affecting the health of fish populations including habitat, hatcheries, harvest, and hydropower (the four Hs) impacts.

The fish abundance data in this report is from the Washington Department of Fish and Wildlife. For more detailed information about methods and data sources, visit the Salmon Conservation and Reporting Engine.

Juvenile Abundance (Juvenile out-migrants) – What does this indicator mean?

The abundance of juvenile (young) salmon is one of several measures that tell scientists about the health and productivity of rivers in Washington State. Some rivers may have more juveniles simply because they are larger, other rivers may have more juveniles because the habitat is better.

To compare rivers, we measure “juveniles per mile” or juvenile density. Juvenile density is the total number of smolts produced in a river divided by the amount of area available for freshwater rearing. This measure is used to assess watershed health–a healthy river will support higher densities of juvenile salmon than an unhealthy one.

In addition to measuring freshwater density, scientists combine information on the numbers of juvenile salmon with the number of wild adult fish that spawn in order to understand fish survival at each stage of their lives, specifically in freshwater or saltwater. This measure is used to assess which life stage and which growing environment is contributing to long-term trends, either positive or negative, for the population.

The juvenile abundance data in this report is from the Washington Department of Fish and Wildlife. The department tracks juvenile abundance densities to varying degrees across the state.

Habitat Projects – What does this indicator mean?

In some areas, habitat has been restored and the number of fish has increased. Washington’s salmon recovery organizations and tribes work hard to restore and protect salmon, steelhead, and bull trout habitat all over the state.

Included here are restoration measures for three types of projects: riparian habitat treatments, estuary habitat treatments, and fish passage barrier corrections.

For more detailed information about these essential activities, visit the Recreation and Conservation Office’s Habitat Work Schedule and PRISM Project Search public databases, the Lower Columbia Fish Recovery Board’s SalmonPORT, and data from the Washington Department of Natural Resources.

Recovery Progress – What does this indicator mean?

Salmon recovery in Washington is driven by regional salmon recovery plans. The recovery plans provide the actions and rationale for where to invest and when. This indicator is measured by comparing the actions implemented against what is recommended in the regional recovery plan.

The data sources for this indicator are the regional salmon recovery organizations. Percentages are statewide averages based on estimates made by each recovery region of its progress implementing actions in recovery plans. These regional estimates are based on best professional judgment. The estimates describe progress in implementing recovery plan actions, and do not reflect the biological response of fish.

While these regional determinations are based on best professional judgment, they are grounded in the regional organizations’ extensive knowledge of recovery issues and recovery progress. Because not every regional organization tracks recovery implementation progress for each “H” (habitat, hatchery, harvest, and hydropower), some percentages are based on the remaining regions that do track each “H.”

Harvest – What does this indicator mean?

Washington tribes and Washington State co-manage fisheries to provide harvest opportunities for salmon and steelhead. Harvest focuses on hatchery and healthy natural-origin fish. As a fish population increases or decreases, harvest managers adjust the amount of catch, matching fishing to fish availability. Beyond Washington, our salmon and steelhead are largely harvested in Alaska and Canada.

The charts of the Washington Department of Fish and Wildlife data in Puget Sound show where harvest occurs and the percentage of years of compliance with the Endangered Species Act. This helps answer the question, “Are salmon harvest rates being held to levels that do not further threaten or endanger listed populations?”

The co-managers, in cooperation with federal agencies and other states, set fishing seasons. Harvest management seeks to achieve population-specific conservation goals for Endangered Species Act-listed fish. Caps on harvest-related impacts are intended to provide additional protection. This means that the maximum fish harvest in an area is set by the “weakest link” present in that area.

The harvest charts from the Washington Department of Fish and Wildlife illustrate historic and present day catch numbers over time based on sport catch record cards and commercial landings. The fish caught are hatchery and wild coho and Chinook salmon in both marine water and freshwater. Tribal catch is included.

Ecological Concerns – What does this indicator mean?

Ecological concerns were developed by NOAA Fisheries and are similar to “limiting factors” referred to in recovery plans. Each regional recovery plan has its own set of ecological concerns, which are changes to habitat that can lead to threats to salmon and steelhead survival. The charts for this measure show percentages of projects that address the main ecological concerns for two regions, the Upper Columbia River Salmon Recovery Region and the Snake River Salmon Recovery Region. Percentages are shown by subbasin and by ecological concern.

Tracking ecological concerns and habitat restoration facilitates more efficient and strategic planning. Tracking ecological concerns also allows for the assessment of habitat actions and their benefits to listed species and how these benefits may contribute to recovery.

Funding – What does this indicator mean?

Funding charts in this report show 1999-2017 salmon recovery funds by region and project type, administered by the Washington State Recreation and Conservation Office.

The Recreation and Conservation Office is a state agency that administers multiple funds and staffs multiple boards, including the Salmon Recovery Funding Board. The charts in the Web site indicate how the funding was distributed across the state.

State funding sources:
Aquatic Lands Enhancement Account, Catastrophic Flood Relief program (through the Office of Financial Management), Coastal Restoration Grants, Estuary and Salmon Restoration Program, Family Forest Fish Passage Program, Brian Abbott Fish Barrier Removal Board, Puget Sound Acquisition and Restoration fund, Salmon recovery fund (state match to federal grant), Washington Wildlife and Recreation Program.

Federal funding sources:
Coded Wire Tag Program, Environmental Protection Agency, hatchery reform funds, Land and Water Conservation Fund, Marine Shoreline Protection (through the Department of Fish and Wildlife), Pacific Coastal Salmon Recovery Fund, Pacific States Marine Fisheries Commission, and Puget Sound Chinook critical stock program.

Note: The $982 million total shown in the statewide chart and the numbers in the regional charts do not include local matching resources, which would bring the statewide total investment to more than $1.2 billion.

How do I get more information on the projects?
The Salmon Recovery Funding Board awards funding to projects during public meetings and presents detailed information online to ensure the funding process is visible and accountable to the public. Information on individual projects can be viewed on the Recreation and Conservation Office’s Project Snapshot and the Habitat Work Schedule.

Hatchery Management – What does this indicator mean?

Congress established a hatchery reform project in 2000, in recognition of the role of hatcheries in meeting harvest and conservation goals for salmon and steelhead. The initiative’s independent Hatchery Scientific Review Group made recommendations for improving hatcheries in Washington.

Eighty-eight percent of Washington Department of Fish and Wildlife’s hatcheries are consistent with the independent the review group’s recommendations for proper broodstock management.

The charts about hatcheries in this report show the progress the Washington Department of Fish and Wildlife has made toward addressing recommendations for proper broodstock management within its programs. Achieving broodstock management recommendations presumes that hatchery programs operate in a manner that poses the least amount of biological risk to associated naturally spawning populations.

In addition, the department has updated and submitted new hatchery genetic management plans to meet NOAA Fisheries requirements under the Endangered Species Act and support salmon recovery. Most of these plans are either approved or under NOAA review. Because (due to past practices) rates that hatchery fish stray in some watersheds remain significantly above the review group’s recommendations and pose a risk to recovery, the department has established rigorous monitoring and adaptive management programs that meet federal permit requirements and reduce stray rates and risks to salmon recovery. Tens of millions of dollars are needed for capital construction projects at department hatcheries to meet recovery goals.

This report shows the Washington Department of Fish and Wildlife hatchery program locations, and whether each program has a Hatchery and Genetic Management Plan.

Water Quality – What does this indicator mean?

Clean and reliably available water is essential for safe drinking, sustaining farms and gardens, swimming, and boating. Cold water is essential for many fish species including recovering salmon and steelhead.

Routine freshwater monitoring data collected by the Washington State Department of Ecology’s River and Stream Monitoring Program are summarized by a technique called the “Water Quality Index” (WQI). The index ranges from 1 (poor quality) to 100 (good quality).

The map shows the most recent year’s water quality index scores for long-term stations with 5 or more years of monthly data, and may include stations monitored by organizations other than the Department of Ecology.

All current long-term Ecology monitoring stations with at least 5 years of data are included. Most stations shown are near the mouths of major streams. These stations integrate upstream water quality and capture large basin-scale trends. However, status and trends at these locations may not reflect status or trends in any particular subbasin.

Annual scores were determined by water year (WY), which runs from October to September, beginning with Water Year 1994.

The index summary does not include non-standard elements like metals. For temperature, pH, oxygen, and fecal coliform bacteria, the index is based on criteria in Washington’s Water Quality Standards, Washington Administrative Code 173-201A. For nutrient and sediment measures where standards are not specific, results are based on expected conditions in a given region. Multiple constituents are combined and results aggregated over time to produce a single score for each station and each year.

The Puget Sound chart in the region’s water quality section shows Annual Water Quality Index scores for monitoring stations near the mouth of 14 major rivers. Higher numbers indicate better water quality. Source: Statewide Water Quality Monitoring Network, Washington State Department of Ecology; Stream and River Water Quality Monitoring, King County.

Find out more about water quality: The Department of Ecology’s Water Quality Atlas is an interactive search and mapping tool that accesses Water Quality Assessment category results by geographic location, water quality standards by location, areas covered by Total Maximum Daily Loads (TMDLs), and permitted wastewater discharge outfalls.

The Department of Ecology’s Freshwater Information Network is an interactive, map-based tool to search for freshwater monitoring data and sites across the state and is the source behind the Water Quality Index data presented in this report.

Stream Flow (Water Quantity) – What does this indicator mean?

The data in the water quantity map shows whether the long-term trends of annual summer low flow levels are declining or increasing. The trends map shows data collected since 1975, representing more than 35 years of measurements. The advantage of a long-term data set is that the influence of annual weather differences and cyclic climate changes (e.g. el niño and la niña; or the phases of the Pacific decadal oscillation) are minimized over time. Because trends are measured over decades, this indicator is not sensitive to relatively short-term changes occurring over just a few years even if significant flow restoration occurs. To measure a change in trend, either large changes in flow must occur (such as a dam setting minimum downstream flows) or a very consistent change over a long period of time is needed.

Habitat Status and Trends (Habitat Quality) — What do these indicators mean?

How do we measure the quality of Washington’s habitats? The Watershed Health Monitoring program, run by the Washington Department of Ecology, measures the statewide and regional status and trends of stream habitat. It collects data about physical and biological conditions in streams and adjacent riparian areas. This includes shade, wood, bottom sediment, water-dwelling species, and human-created disturbance features. This is an important statewide monitoring program. In this report, we show information about six measured qualities that are relevant to salmon: sediment, sediment copper, large wood volume, riparian cover, riparian disturbance, and an index of biotic integrity. Riparian areas are shorelines, streambanks, wetlands, and floodplains next to bodies of water that support and protect the health of the water. Biotic integrity is “[t]he ability to support and maintain a balanced, integrated adaptive assemblage of organisms having species composition, diversity, and functional organization comparable to that of natural habitat of the region.” (Karr and Dudley 1981). In this report, the Department of Ecology examined biotic integrity for one assemblage, stream invertebrates.

Sediment in Salmon and Trout Streams
One big factor that limits salmon recovery is sediment. Sediment is a great cause of lowering stream health in Washington. Although sedimentation is part of the natural cycle, land-disturbing activities cause extra sand and finer-sized particles to run into streams. This excess sediment causes many problems for salmon, including smothering fish eggs, changing the shape and route of the stream, and reducing stream capacity to hold floodwater or provide cover for fish.

The graph in this site shows sediment conditions for salmon and trout streams in each salmon recovery region. Department of Ecology field crews looked at hundreds of equally-spaced locations on the bottom of hundreds of streams and counted how many locations in each stream were occupied by particles that were the size of sand or smaller. Based on one report (Bryce et al., 2010), 18.5 percent sediment in a stream is generally the best for sediment-sensitive salmon and trout. Therefore more than 18.5 percent sediment is considered too much. (Note: The Department of Ecology added 5.5% to Bryce values after comparing results from two field methods. Department of Ecology measures across a larger portion of the stream channel than does Bryce.)

Copper in Stream Sediments

The graph in this site shows the amount of copper in stream-bottom sediments as measured statewide by the Department of Ecology’s Watershed Health Monitoring program during 2009 through 2012. The highest values occur in forested portions of southwestern Washington. Thirty-two (32) mg/kg sediment copper might affect stream dwelling creatures and 149 mg/kg probably affects them (Table 13 of DeGasperi et al, 2018). If we reduce the amount of sediment that reaches streams, especially where it contains copper, we will lessen the threat to salmon and other aquatic species.

Riparian Cover 

Riparian areas are lands along watercourses, such as streams and rivers (Natural Resources Conservation Service, 1996). Plants in these areas shield streams and rivers from summer and winter temperature extremes, which can be fatal to fish. Leaves and branches shade the stream, cooling the water for salmon during warm months. Shade also can limit growth of algae, which robs oxygen from the water as it decays, leaving less for fish. The plants also drop branches, leaves, and insects into the water. This provides food for fish. The branches slow the water, and give salmon places to rest while feeding and to hide from predators. Finally, the roots of the streamside plants hold soil and keep it from entering the water and burying spawning gravel.

The chart in this site shows the portion of each salmon recovery region’s stream network that has good, fair, or poor cover in the riparian zone. The Department of Ecology measured riparian cover at randomly selected streams. Each of those streams represents a portion of its salmon recovery region’s stream network. Ecology decided on what levels of riparian cover are good, fair, and poor by examining a separate set of relatively natural reference streams in each of three areas: western Washington, the eastern mountains of Washington, and the Columbia Plateau. During the first statewide sampling round (2009-2012), stream length with poor riparian cover ranged from 12 percent (Washington Coast Salmon Recovery Region) to 27 percent (Upper Columbia River Salmon Recovery Region). During 2013 through 2016, five regions were resampled. Measured extent of poor conditions decreased in four of these regions, and increased in the Middle Columbia River Salmon Recovery Region, a region exceptionally affected by drought. More monitoring is necessary to see if this pattern persists and represents a trend.

Large Wood

Large tree root wads and logs are good for salmon. Healthy watersheds have enough trees to maintain an adequate supply of wood to streams. Otherwise, adding wood to streams is a common way to improve fish habitat. The wood slows the stream, which creates places for fish to rest and hide from predators. A slower stream will erode its banks less, and therefore transport less sediment to the river. Wood also creates deep pools, which are cooler. It also helps streams retain organic matter and nutrients which are a food source for the insects and fish salmon eat.

There is debate about how much benefit wood provides, and how much wood is needed. Longer-term studies of whole watersheds could help us understand where wood occurs naturally, how much, and what type of wood. This could guide future wood placement projects to increase their effectiveness.

The map in this site shows the amount of wood in streams measured by the Department of Ecology’s Watershed Health Monitoring program during 2009 through 2016. Ratings are based on comparison to references streams (see “Watershed Health Monitoring: Wood Volume in Streams” in data.wa.gov for details). Scoring levels depend upon the natural setting and the width of the stream. Most monitored streams statewide have low amounts of wood when compared to relatively natural conditions. This suggests that salmon and trout could benefit from the growth of more streamside trees as sources of wood. This is true, even in dry parts of the state, where natural conditions are less conducive to tree growth.

Stream Biological Health — Bug Counts

A Benthic Index of Biotic Integrity (BIBI) measures collections of insects and similarly sized animals found on stream bottoms. Scientists look at their species compositions to assess stream conditions. Each species has a characteristic response to human-caused environmental changes. Ten data values (metrics) are combined into a single number (index) that provides an overall score. These types of indexes are used by many environmental monitoring programs throughout the Northwest and the world. The Department of Ecology has assigned good, fair, or poor ratings to BIBI scores, based on comparison to relatively natural conditions in each of three zones in the state: western Washington, eastern mountains, and the Columbia Plateau.

The bars in the graph in this Web site reflect percent of estimated stream length represented by randomly selected sites, sampled in each salmon recovery region for a given survey year, with good, fair, or poor BIBI scores.


Initial sampling of the state happened in 2009-2012. Extent of streams estimated to have poor biological integrity ranged from 17 percent of kilometers in the Lower Columbia and Upper Columbia River Salmon Recovery Regions to 44 percent of the kilometers in the Puget Sound Salmon Recovery Region.


During 2013 through 2016, five salmon recovery regions were re-sampled. The biological integrity improved in three regions (Puget Sound, Snake River, and middle Columbia River). It remained unchanged in the Coastal region, and it got worse in the lower Columbia region. More monitoring is necessary to see if these patterns persist and represent trends.

Human Disturbance in Riparian Habitat

“Riparian zones are one of the key drivers of salmon habitat quantity and quality, especially where riparian buffers protect the stream from adjacent land uses.” (NOAA-Fisheries 2018).

Riparian areas are shorelines, streambanks, wetlands, and floodplains next to bodies of water that support and protect the health of the water. Department of Ecology crews looked at land in riparian areas and noted human-created features and their closeness to the streams. Using this information, they calculated an index of riparian disturbance for randomly-selected sample streams that each represent a portion of the watershed stream network. The graph in this site shows the extent of streams in the salmon recovery regions estimated to be highly disturbance. During the first statewide sampling round, stream length with highly disturbed riparian zones ranged from 33 percent (Snake River) to none (Washington Coast). During 2013 through 2016, five regions were resampled. Less land was disturbed in the Puget Sound Region, and barely changed in other regions. More monitoring is necessary to see if this pattern persists and represents a trend.