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Geographic Information Systems (GIS) are valuable for finding equitable solutions to long-term land and resource management problems. They are especially useful for tracking and visualizing oil spills, identifying endangered species habitat, acid rain, deforestation, desertification, wetland destruction, and depletion of the ozone layer (Cowen 1994).

The National Marine Fisheries Service (NMFS), in cooperation with NOAA's National Environmental Satellite, Data, and Information Service (NESDIS) and Environmental Services Data Information Management (ESDIM) program, initiated the development of a desktop GIS database to consolidate recent west coast salmonid spawning-escapement estimates, hatchery releases, and relevant spawning and rearing habitat information.

We developed a desktop GIS to address salmonid population and habitat issues related to the decline of salmonid populations within the Pacific Northwest. Once-abundant populations of salmonid stocks in the Northwest are currently at record low levels. These low population sizes are related to a variety of factors including dams, destruction of spawning and rearing habitat, overfishing, poor ocean conditions, water pollution, loss of genetic integrity, and disease. Consequently, commercial and sport harvests of Northwest anadromous resources have declined significantly. The Columbia River in particular, which once had the largest chinook salmon (Oncorhynchus tshawytscha) runs in the world with annual harvest over 45.5 million pounds, had only 1.4 million pounds or 115,000 salmon commercially harvested in 1993 (WDFW and ODFW 1994). There once were many salmon canneries operating on the Columbia River, employing many people, but today there are none.

Many populations of salmon are at very low levels. Nehlsen et al. (1991) identified 214 Northwest salmon stocks as either threatened, endangered, at risk, or of special concern. They also concluded that at least 106 Northwest salmon populations are now extinct. The plight of Northwest salmon populations is evident by the listing of Sacramento River (California) winter chinook salmon, the Snake River spring/summer and fall chinook salmon stocks, and Snake River sockeye salmon (O. nerka) as threatened or endangered under the Endangered Species Act (ESA).

Since salmon utilize freshwater habitats to rear and spawn, they are relatively easy to enumerate, both at dam or weir passage facilities or on the spawning grounds. Counts of adult salmon have been the traditional method used by fishery managers to calculate adult run sizes. Although many state, federal, and tribal resource agencies presently collect salmonid adult spawning escapement and habitat data, no agency has assumed the responsibility for developing a coastwide database or monitoring program. Nehlsen et al. (1991) recommended developing such a long-term monitoring program to track the status of all anadromous fish populations on the Pacific Coast.

A comprehensive Northwest salmonid GIS database of salmonid resources and habitat characteristics will have wide-ranging applications. It will assist the Pacific Fishery Management Council with the difficult task of managing mixed-stock fisheries and assist NMFS in considering petitioned west coast salmonid stocks for ESA listing. Furthermore, the GIS will help identify how past and future habitat alterations affect salmonid populations. A salmonid GIS will save resources spent on data searches as well as provide fishery scientists a multi-layered view of related data sets. Viewing data in a spatial and graphical environment greatly enhances the ability to analyze data, draw conclusions, and predict outcomes (Burrough 1986).

Ideally the physical and biological data can be updated quickly, and new attributes can be added as needed. This is important when NMFS is determining whether local salmonid populations qualify as distinct population segments or as habitat management decisions are made. A GIS can also help determine whether trends in a salmon population's abundance are the result of some region-wide or large-scale environmental or climatological event, or the result of local environmental perturbations such as habitat degradation.

Developing a complete, working salmonid GIS database for the entire Northwest is a large project that requires many steps before completion. As such, we initiated a pilot study, with the Columbia River Basin selected as our initial watershed. The Columbia River Basin was chosen because it 1) has a long history of salmonid habitat data collections, 2) is the largest river basin in the Northwest, 3) has many different stocks of salmonids and habitats, and 4) has undergone significant development. Furthermore, any technical problems or obstacles hindering development of a salmonid GIS database would become evident while working on a river basin of this complexity.

Three earlier studies were initially evaluated to identify similar techniques that could be employed to build a salmonid GIS database. One of the earliest efforts towards developing a database of west coast salmonid spawning streams and hatchery production was made by Wahle and Pearson (1987). They listed all Pacific coast salmon spawning streams and hatcheries producing chinook and coho salmon and estimated the number of spawners and the number of hatchery fish released during 1984-1985 (Wahle and Pearson 1987). Their study provided an excellent reference of spawning streams by species along with estimates of adult salmon spawners in each stream during 1984-1985, but did not provide any historical values. Unfortunately, a similar follow-up survey has not been conducted.

A second study by Konkel and McIntyre (1987) identified population trends in spawning populations of Pacific anadromous salmonids from 1968 to 1984. They developed a computerized database containing more than 25,000 escapement records for more than 1,000 locations. Using this database, Konkel and McIntyre (1987) tabulated salmonid population trends by region and identified areas with major data deficiencies. They found significant trends in 30% of the populations, with chum and coho salmon escapement trends predominately decreasing. In general, there were three populations that decreased for every site with an increasing trend in adult salmon escapement.

The Wilderness Society (1993) described the present and past geographic distribution of salmonid populations in the Northwest. Using a GIS, they showed the distribution of salmon species in the Northwest and calculated what percentage of these populations were extinct, endangered, of special concern, or not known to be declining. They concluded that damage to spawning and rearing habitat caused problems for all salmon species, and that essentially all Northwest salmonid species have populations that are either extinct or at risk of extinction over a majority of their range.

Following the literature review, we identified three primary objectives: 1) determine whether a GIS for salmonid resources could be developed for the Columbia River Basin and, if so, then 2) create a salmon GIS that would show geographic and historical data sets by stream, and 3) gather and show physical data which could be associated with salmon habitat and population abundance.

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