This contract for FY2025 is approved under the Columbia Basin Fish Accords Extension with the Confederated Tribes of the Umatilla Indian Reservation (CTUIR).   Since its inception in 2002, the Freshwater Mussel Project of the CTUIR has conducted research designed to understand the biology, ecology, and status of freshwater mussels in the western United States. Specifically, the project has focused on three main study areas designed to: 1) determine the status and distribution of freshwater mussels in CTUIR Tribal lands; (2) investigate factors controlling the distribution and abundance of mussels, and (3) to assess genetic differences among western freshwater mussel species in the Columbia River basin. The project now begins focus on the long-term goal of restoration of freshwater mussels to the Umatilla River basin and other ceded subbasins as part of ongoing efforts to rebuild ecosystem diversity, function, and traditional cultural opportunities in the region.

Freshwater mussels in western North America (Genera Anodonta, Margaritifera, and Gonidea) are notoriously understudied, although they have historically been a major component of the biomass in western aquatic systems and likely have a disproportionately large impact on ecological stability and processes in these systems. BPA and CTUIR have funded pioneering work on the genetic composition and taxonomy of western freshwater mussels. Now that the basic genetic subdivisions and landscape patterns of genetic variance have been described for these groups of mussels, studies focused on habitat requirements and ecological roles can be designed appropriately. Such studies are critical for effective monitoring, conservation, and restoration programs.  

CTUIR's interest in conserving freshwater mussels and restoring viable populations is in the context of “First Foods” resource management on Tribal and ceded lands. One of the major goals of the CTUIR freshwater mussel project is to restore sustainable populations of freshwater mussels to the Umatilla River system and other ceded subbasins. The John Day, Grande Ronde, Tucannon, and Walla Walla River systems, on ceded lands, contain populations of freshwater mussels, and are a high priority for conservation. These river systems (particularly the John Day) also provide opportunities to study the distribution, habitat requirements, and ecosystem functions of freshwater mussels. Conclusions drawn from the distribution of mussels in this system can inform restoration efforts in other rivers, such as the Umatilla.

This contract year seeks to continue long term monitoring of mussel populations, improve and apply methods for juvenile mussel propagation and culture, to initiate a landscape scale analysis of mussel habitat and distribution, to finalize development of a master supplementation plan that will guide mussel population recovery and conservation this year and in future contract years.