Salmonid Stock Inventory (SaSI)

What is SaSI?

Washington's eleven species and subspecies of native salmonid fish constitute a biological resource of spectacular commercial and cultural importance. Unfortunately, this resource is under heavy pressure from human population growth and development. Urban and industrial land conversion, forestry and agricultural practices, water diversion, municipal water demands, overfishing, and hydropower development have contributed to the decline of several salmonid stocks. A large recovery effort at the local, state, and federal level is currently underway to prevent further declines and improve the condition of already imperiled stocks.

An invaluable tool in the process of restoring stocks to healthy and productive levels is the Salmonid Stock Inventory (SaSI). SaSI is a standardized, uniform approach to identifying and monitoring the status of Washington's salmonid stocks. The inventory is a compilation of data on all wild stocks and a scientific determination of the status of each stock as: healthy, depressed, critical, extinct, or unknown. SaSI thus provides a basis for prioritizing recovery efforts and measuring the results of recovery actions. SaSI is a cooperative product of the Washington Department of Fish and Wildlife and tribal co-managers.

SaSI development began in 1992 as an effort by 20 western Washington native tribes and the Washington Department of Fish and Wildlife's predecessor agencies, the Washington Department of Fisheries and the Washington Department of Game. At that time the inventory was called the Salmon and Steelhead Stock Inventory (SASSI). The SASSI documents produced in 1993-4 totaled some 2600 pages and described and categorized the status of 435 salmon and steelhead stocks.

In 1997 the Washington Department of Fish and Wildlife produced an additional volume on bull trout and Dolly Varden and, with this inclusion of salmonid fishes which were neither salmon nor steelhead, the inventory was renamed the Salmonid Stock Inventory (SaSI). The bull trout/Dolly Varden inventory was updated in 1998 and a coastal cutthroat trout stock inventory was completed in 2000.

The co-managers' original intent was to regularly update and revise SaSI documents, and with the 1999 creation of the Salmonid Stock Conservation Biology Unit in WDFW's Fish Program a comprehensive updating and revision of the SaSI documents was completed in 2002. New data handling and reporting protocols finalized in 2008 mean that SaSI can now be updated by WDFW staff as new information about a given stock becomes available, rather than waiting several years for a comprehensive update.  These updates are then immediately available to the public and other scientists through SalmonScape or direct data requests.

What is the Current SaSI Understanding of Stock Status?

The 1993-1994 SASSI documents recognized 435 stocks of salmon and steelhead. SaSI defines a stock as a group of fish that return to spawn in a given area at the same time and that are, for the most part, reproductively isolated from other such groups. A stock may include several local spawning populations. A ‘run’ of fish may include more than one stock returning at the same time but destined for different spawning grounds . The 2002 update recognized an additional 54 stocks for a total of 489 salmon and steelhead stocks. The 1998 bull trout/Dolly Varden stock inventory recognized another 74 stocks. Bull trout and Dolly Varden are taxonomically distinct species but are difficult to distinguish in the field in Washington, and no attempt was made to separate them in the stock inventory. The 2000 coastal cutthroat trout stock inventory recognized 38 stocks. The number of stocks in each category (defined below) is presented in the table below.

A total of 598 stocks have been identified. Of these, 180 stocks (30%) were rated as Healthy, 132 stocks (22%) were rated as Depressed, 26 (4%) were rated as Critical, and 251(42%) were of Unknown status. The percentage of stocks of Unknown status varies considerably, from 10% in Chinook to 78% in coastal cutthroat trout.

Critical stocks are those that have declined to the point that the stocks are in danger of significant loss of genetic diversity, or are at risk of extinction. Stocks now listed under the Endangered Species Act are in red type.

Ahtanum Creek -- bull trout
Box Canyon Creek -- bull trout
Chewuch River -- spring Chinook
Clearwater River -- spring/summer Chinook
Crow Creek -- bull trout
Deschutes -- coho
Discovery Bay -- coho
Dungeness River -- Chinook
Dungeness River (lower) -- pink
Elwha River -- pink
Entiat River -- spring Chinook
Gold Creek (Yakima) -- bull trout
Jimmycomelately Creek -- summer chum
Kachess River -- bull trout
Lake Washington -- winter steelhead
Lilliwaup Creek -- summer chum
Little Wenatchee River -- spring Chinook
Lost River -- spring Chinook
Methow River -- spring Chinook
Mid Hood Canal -- Chinook
North Fork/Middle Fork Nooksack River -- Chinook
South Fork Nooksack River -- Chinook
Teanaway River, North Fork -- bull trout
Twisp River -- spring Chinook
White (Puyallup) River -- spring Chinook
White (Wenatchee) River -- spring Chinook
Wind Tule River -- fall Chinook
Yakima River -- bull trout

What are the Extinct Stocks?

Extinct stocks are those that are no longer present in their original range or as a distinct stock elsewhere. Individuals of the same species may exist in very low numbers on the spawning groups, consistent with straying from other stocks. SaSI does not identify stocks that went extinct in the distant past, but 9 stocks were determined to have gone extinct during recent times. Note that for many of the summer chum stocks listed programs are currently being administered to reestablish viable stocks from genetically similar brood stock.

Anderson Creek -- summer chum
Asotin Creek -- spring Chinook
Big Beef Creek -- summer chum
Chambers Creek -- summer chum
Chimacum Creek -- summer chum
Dewatto River -- summer chum
Finch Creek -- summer chum
Skokomish Creek -- summer chum
Tahuya River -- summer chum

Other Stock Classifications

Healthy: 30% of the stocks were found to be healthy. The term ‘healthy’ covers a wide range of actual conditions, from robust to those without surplus production for harvest. Just because a stock is listed as healthy does not necessarily mean managers have no current concerns or that production levels are adequate. Some SaSI stocks listed as healthy are in fact listed under the Endangered Species Act because listings are made on stock groups called evolutionarily significant units (ESUs). Also, keep in mind that most stock determinations were made in 2002, and that status of some stocks may have changed since then.

Depressed: A depressed stock is one whose production is below expected levels, based on available habitat and natural variation in survival rates, but above where permanent damage is likely. 22% of stocks were determined to be depressed.

Unknown: For many stocks, there simply is insufficient information to rate them. Many of these are historically small populations and could be especially vulnerable to any negative impacts. There is an immediate need to collect more information on them.