Columbia River Basin Fish Research Articles

Genetics Reveal Long-Distance Virus Transmission Links in Pacific Salmon.

Simple SummaryThe transmission of viruses between host populations is essential for viruses to persist on the landscape. Therefore, the identification of specific transmission links can provide insights into how a virus moves from source to recipient (sink) populations, allowing for the development of strategies to interrupt transmission routes and control viral disease. For the fish pathogen infectious hematopoietic necrosis virus (IHNV), this study identifies three transmission links associated with the emergence of IHNV in coastal Washington steelhead trout populations between 2007 and 2011. The links were identified by the genetic typing of virus isolates obtained from coastal fish and potential source fish from the Columbia River Basin. Three exact genotype matches were found, indicating at least three introductions of virus from Columbia fish to coastal fish during years of the emergence event. Likely sources were juvenile fish in the Columbia region experiencing disease, and the first detected recipient populations in all cases were adult fish returning to coastal hatcheries. Variation in timing and distance for these three transmission links will provide Pacific Northwest fish health managers with a better understanding of IHNV transmission routes from Columbia region fish to coastal steelhead trout.In the coastal region of Washington State, a major pathogen emergence event occurred between 2007 and 2011 in which steelhead trout (Oncorhynchus mykiss) experienced a high incidence of infection and disease outbreaks due to the rhabdovirus infectious hematopoietic necrosis virus (IHNV). Genetic typing showed that the introduced viruses were in the steelhead-specific MD subgroup of IHNV and indicated the most likely source was a virus from the nearby Columbia River Basin. In the current study, full-length viral glycoprotein (G) gene sequences were determined for 55 IHNV isolates from both coastal and Columbia fish populations to identify specific source populations and infer mechanisms of transmission to coastal steelhead. We identified three transmission links based on exact fullG genotype matches between Columbia and coastal fish. In all cases, the likely source population was infected juvenile fish, and sink populations were adult fish returning to coastal rivers to spawn. The time intervals between detection in source and sink populations varied from 6 months to nearly 4 years, suggesting different transmission pathways. Surprisingly, distances between source and sink populations varied between 140 and 1000 km. These results confirm repeated introductions of virus from Columbia River Basin fish as the cause of emergence of MD virus on the Washington coast from 2007 to 2011.

Research, Monitoring, and Evaluation of Fish and Wildlife Restoration Projects in the Columbia River Basin: Lessons Learned and Suggestions for Large-Scale Monitoring Programs

Abstract The year 2006 marked two milestones in the Columbia River Basin and the Pacific Northwest region's efforts to rebuild its once great salmon and steelhead runs—the 25th anniversary of the creation of the Northwest Power and Conservation Council and the 10th anniversary of an amendment to the Northwest Power Act that formalized scientific peer review of the council's Fish and Wildlife Program and its varied individual projects. The authors of this article served as peer reviewers in the last decade. Restoration efforts in the Columbia River constitute a massive long-term attempt at fisheries and ecosystem restoration. In this article we examine some of the lessons we learned in reviewing the research, monitoring, and evaluation efforts of projects and their effects on advancing knowledge (i.e., adaptive management) in the Columbia River Basin Fish and Wildlife Program, one of the most ambitious and expensive long-term ecological restoration programs in the United States.

Resident Fish in the Columbia River Basin

Abstract Development and operation of Columbia River Basin hydroelectric facilities have contributed to the reduction in diversity and abundance of some native resident fish. To mitigate for effects of hydroelectric development and operations, the Bonneville Power Administration (BPA) annually funds fisheries research and management efforts. In 2003, the BPA provided $19.2 million for the implementation of 54 resident fish projects that were recommended for funding by the Columbia Basin Fish and Wildlife Authority and Northwest Power and Conservation Council through the council's Columbia River Basin Fish and Wildlife Program. Through the resident fish segment of this program, managers have begun to better understand and manage impacted resident fish habitats and populations; however, restoration of resident fish populations will require cooperation among resident and anadromous fish mangers, hydrosystem operators, and federal regulators. Managers must ensure that power, water management, and land-use dec...

Return to the River: Scientific Issues in the Restoration of Salmonid Fishes in the Columbia River

Abstract The Columbia River once was one of the most productive river basins for anadromous salmonids on the West Coast of North America; however, its current runs total less than 10% of historic levels. The Independent Scientific Group (ISG) of the Northwest Power Planning Council reviewed regional salmon management actions described in the Columbia River Basin Fish and Wildlife Program and concluded that the current program is unlikely to recover declining salmon and steelhead stocks. Adoption of a salmon life history ecosystem concept as a guiding foundation is needed to recover depressed stocks. Increasing natural ecosystem processes and functions should rebuild salmon populations to more abundant, productive, and stable levels. Elements of a salmon recovery program that increase these normative conditions include restoration of habitat for all life history stages (including migrations), reduction of mortality sources (including harvesters), planning of hydropower mitigation measures in the context of...