As much as TU has accomplished over the past 50 years, the challenges we face today are as formidable as ever.  And as much as we’ve grown our scientific and economic resources, we can’t ever hope to do it all.

So where do we go from here? How can we best apply our limited resources and time for the greatest benefit?

The Conservation Success Index (CSI), developed and being implemented by TU staff scientists, shows great promise as the tool that will drive our priorities and strategies to protect, reconnect, restore and sustain coldwater fisheries.

The CSI is a computer model that analyzes sub-watersheds based on factors such as habitat quality, population density and future security to identify opportunities for conservation efforts.

Using cumulative CSI “scores,” we can determine whether a particular area might warrant habitat restoration to increase native trout density, or “reconnecting” stream segments by removing obstacles to fish passage and interaction among populations., or campaigning to protect pure-bred strains of native trout.

Initial CSI analyses focused on native trout species and have recently expanded to wild trout in Colorado and Wyoming.

Read more below

Using the CSI to Protect, Reconnect, Restore and Sustain Coldwater Fisheries and Their Watersheds

This article  briefly describes how you can use Trout Unlimited’s Conservation Success Index (CSI) to identify conservation projects for coldwater fishes and their habitats. The CSI includes loads of maps, data, and reports that may be useful. This information can be found on the TU main website www.tu.org by clicking on the “Science” button along the top banner. You can review the main CSI webpages, reports generated by CSI data, and a more detailed CSI user guide.

Much of the CSI information and maps cover broad geographic areas. The primary analysis area is the subwatershed, which often covers 10,000 to 20,000 acres. The subwatersheds are scored separately for the various CSI indicators and are given specific colors in the CSI maps that reflect these scores.

Because each subwatershed covers a large amount of country, identifying the best projects becomes a 2‐tier process as shown on the figure below. Tier I is the CSI analysis itself, which provides information on population and habitat conditions, and their future security, at the subwatershed scale across entire river basins and species ranges. Tier II is the more local information, which may include site‐specific data on individual stream reaches, individual landowner interests, and agency priorities. This is where the local TU knowledge comes in. The best projects are those that integrate these local issues and concerns with the broader context of habitat and population conditions.

We have developed relatively simple opportunities maps for most of the species covered in the CSI. These maps show highest priority strategies for each subwatershed based on comparing scores of the CSI indicators for population integrity, habitat integrity, and future security. For example, if a subwatershed scores high for both habitat integrity and population integrity, it will show a high priority for protection. Similarly, if a subwatershed scores high for population integrity but lower for habitat integrity, habitat restoration is indicated.

The map to the left shows priority management opportunities for Bonneville cutthroat trout. Of course, when these types of CSI priorities are combined with local information (Tier II above), you may find that multiple management actions such as protection and restoration are needed in individual subwatersheds.

Can We Use the CSI for Wild Trout?

Although primarily developed for native coldwater fishes, the CSI can be helpful for identifying projects for wild trout in a couple of ways. First, we have completed a few CSI analyses specifically for wild trout in such areas as Colorado and Wyoming’s North Platte River (see map at right) and Idaho’s Big Lost Basin. Second, our geographic coverage for native trout overlaps with many wild trout areas and can be used to identify PRRS opportunities for wild populations of brown, brook, and rainbow trout. For example, the CSI provides scores for habitat integrity and future security indicators for the entire historic range of each native trout species. These ranges typically extend far beyond the current range of native trout and include many streams now inhabited by wild trout. So, those scores describe current habitat conditions and limiting factors for many wild trout populations.

Where Can I Get More Information?

Sabrina Beus in our Boise, Idaho, office can answer questions or help direct you to the appropriate TU science staff. She can be contacted at sbeus@tu.org.