Overview:

Native resident salmonids are in decline in many portions of their historical range due in part to a variety of anthropogenic factors such as irrigation diversions, agriculture impacts, and hydropower dams (both federal and private). As a result, several resident salmonids are either listed or have been petitioned to be listed under the Endangered Species Act (ESA). This is a multi-phased project by the Idaho Department of Fish and Game with the goal of protecting and restoring populations of native salmonids (those listed above, and mountain whitefish) in the Upper Snake River Basin (USRB) above Hell's Canyon Dam in Idaho to self-sustaining, harvestable levels. The overall objectives (or phases) are to: 1) Assess stock status, population trends, and fish habitat; 2) Identify life history and habitat needs, and limiting factors; and 3) Develop, implement, and monitor the effectiveness of recovery and protection plans for populations at risk. The first phase of inventorying fish and their habitat was completed in FY05; status assessments have been finalized for bull trout and Yellowstone cutthroat trout and are underway for redband trout and mountain whitefish. We have randomly sampled stream locations to assess the current status of native salmonids throughout the USRB, and assess what factors influence that status. Relating fish abundance and distribution to stream and adjacent habitat conditions led directly to limiting factor analysis (Phase II), which is ongoing. Limiting factor analysis has included identifying life history needs, causes for population declines, threats to persistence, and opportunities for restoration. Once limiting factors are identified, the third phase was to use this information to develop recovery and protection plans for populations at risk. However, this project has been terminated by BPA, thus, during this final SOW with a much reduced budget, all that will be conducted will be finalizing the mountain whitefish and redband trout status assessments.

Background:

Since the construction of Swan Falls dam in 1901, the USRB has been heavily impacted by hydroelectric development. Currently there are approximately 92 hydroprojects and countless irrigation diversions making use of Snake River water in the Idaho portion of the basin. These activities, as well as habitat alteration due to logging and grazing practices, and the introduction of exotic fish species, have had impacts on native salmonids. Anadromous salmon and steelhead that used to inhabit the Snake River and its tributaries below Shoshone Falls have been extirpated by dam construction and hydroelectric operations.

Bull trout, redband trout, and Yellowstone cutthroat trout populations have experienced significant reductions in distribution and abundance in much of their historical range and have been petitioned to be or are listed under the ESA. Mountain whitefish are the only other native salmonid in the USRB, and their current status is not well known. Despite the sensitive status of these salmonids, quantitative data on the current distribution, trends, habitat, life history needs, limiting factors, and threats to persistence of native salmonids in the USRB were minimal for most populations before the initiation of this project. The extent of declines in distribution was unclear because most prior assessments of native salmonid status were largely qualitative, and based on professional judgment. Our approach has been to randomly select sampling sites across streams, entire river drainages, and a species' range in Idaho (and adjacent states) to determine present distribution and abundance of salmonids in the Middle and Upper Snake River provinces. We have also gathered as much information as possible from several other sources (federal; states including Wyoming, Utah, Nevada, and Oregon; university, etc.) relative to presence/absence and abundance estimates. Based on these results, current status, effective population size, genetic purity, and interconnectedness of populations of native salmonids are being determined.  Recovery strategies were being developed and implemented at the time of project termination.

Because of project termination, the much-reduced work elements for this Statement of Work (SOW) fall into 2 main Biological Objectives:

1: Finish analysis and writing of a mountain whitefish and redband trout status assessments.
2: Finish the evaluation of the growth of redband trout when water temperatures are at stressful levels to look for differences in growth between fish from desert vs. montane streams.