ABSTRACT
The Panther Creek drainage (east central Idaho) historically supported substantial runs of spring and summer chinook salmon Oncorhynchus tshawytscha and steelhead trout O. mykiss. Since the early 1900s, mining activities within the drainage (and associated releases of heavy metals) have eliminated chinook runs from the basin. In 1995, a biological restoration and compensation program (BRCP) was formulated to identify measures that would lead to development of a self-sustaining run of chinook salmon in Panther Creek. Because of the Endangered Species Act (ESA) endangered status of spring chinook salmon stocks in Idaho, the restoration program was developed with consideration for the source of brood stock, required numbers of adult pairs, rearing practices, and monitoring and evaluation. The development of the BRCP was completed in three steps: selection of restoration/enhancement options; time series analysis to provide a restoration/recovery curve of chinook populations in Panther Creek based on the selected measures; and cost estimation (assigning costs to the BRCP elements). Four general categories of restoration options were identified and evaluated including (1) restoration of populations by hatchery supplementation techniques (preferably using wild donor stocks); (2) creation of additional habitats (within or outside of the Panther Creek drainage) to promote increased survival of fish and increase carrying capacities; (3) restoration and/or enhancement of existing habitats (within or outside of the Panther Creek drainage) to increase fish survival; and (4) reduction in fish losses such as those occurring in irrigation diversions. Specific engineering concepts were identified and evaluated for each category. In addition to engineering options, various biological strategies for reintroducing chinook salmon into the system were evaluated. Although the effectiveness of the program has yet to be determined in Panther Creek, we believe the BRCP as outlined provides the best opportunity for successful reintroduction and restoration of chinook salmon into the system. The general steps completed and considerations addressed in developing this BRCP included those likely to be necessary in other drainages where restoration of depleted or extirpated stocks of salmon and/or steelhead is desired. In those cases, this BRCP process may provide guidance in developing successful and economically feasible reintroduction and restoration programs.
