Step 1 - Current Condition, Status, and Distribution of Native Trout Populations and Associated Stream-Riparian Habitats

Step 1 (figure at right) provides the environmental baseline or current condition for cutthroat trout in the Central Bear River subbasin and is assumed to reflect natural disturbances and the effectiveness of the Forest’s current land use plan direction and past management actions.

Step 1(A) displays the current distribution of cutthroat trout populations across their assumed historical distribution in Central Bear River subbasin. This information was based on stream survey data collected by aquatic researchers as well as State, tribal, and Forest biologists and compiled at the subwatershed level.

The status of the trout population in each subwatershed was coded as strong, depressed, or absent (includes extirpated) based on criteria developed for assessing interior Columbia River Basin fish populations (Lee and others 1997). For example, subwatersheds were coded as having strong populations if the subwatershed had all the following conditions:

• fish presence had been verified within the last 10 years using standard sampling methods;
• major life history stages, (e.g., resident, migratory) that historically occurred in the subwatershed were still present;
• fish numbers were stable or increasing, and the population was no less than half of its historic size or density;
• the population or metapopulation was at least 5,000 individuals or 500 adults; if the population size was based on a population that extended outside the subwatershed, the subwatershed was an important core area for this larger population.

In addition, current conditions of stream-riparian habitats were evaluated for each subwatershed. Qualitative approximations of subwatershed conditions were obtained from Inland West Water Initiative (IWWI) assessments and plotted in step 1(B). The Bridger-Teton National Forest chose to display water quality integrity, but other indicators of watershed condition could have been used.

Data for populations and subwatershed conditions were organized in standardized Excel format. The data were readily displayed and reviewed by creating Geographic Information System (GIS) spatial data layers both by subwatershed and subbasin and creating maps using ArcGIS© tools.

In Forest plan revisions, information developed in step 1 could be incorporated into the comprehensive evaluation report (CER), a constituent of the planning set of documents, which provides current conditions and analyses for the Forest Plan.