Publications

In teleost fish as in mammals, humoral adaptive immunity is based on B lymphocytes expressing highly diverse immunoglobulins (IG). During B cell differentiation, IG loci are subjected to genomic rearrangements of V, D, and J genes, producing a unique antigen receptor expressed on the surface of each lymphocyte. During the course of an immune response to infections or immunizations, B...

The myxozoan parasite Ceratonova shasta is an important pathogen that infects multiple species of Pacific salmonids. Ongoing genetic surveillance has revealed stable host-parasite relationships throughout the parasite's endemic range. We applied Bayesian phylogenetics to test specific hypotheses about the evolution of these host-parasite relationships within the well-studied Klamath...

The prevalence of Ichthyophonus infection in Pacific herring Clupea pallasii was spatially heterogeneous in the southern Salish Sea, Washington State, USA. Over the course of 13 mo, 2232 Pacific herring were sampled from 38 midwater trawls throughout the region. Fork length was positively correlated with Ichthyophonus infection at all sites. After controlling for the positive...

Executive Summary The production of Klamath River fall Chinook salmon (Oncorhynchus tshawytscha) in northern California and southern Oregon is thought to be limited by poor survival during freshwater juvenile life stages, in part a result of Ceratonova shasta—a highly infectious disease that can lead to high fish mortality. Higher flushing river flows are thought to affect the...

Executive Summary In this report, we describe application of the Stream Salmonid Simulator (S3) to Chinook salmon (Oncorhynchus tshawytscha) in the Klamath River between Keno Dam in southern Oregon and the ocean in northern California. S3 is a deterministic life-stage-structured population model that tracks daily growth, movement, and survival of juvenile salmon. It can track different...

Stakeholder interests have spurred the reintroduction of the critically endangered populations of Chinook Salmon to tributaries upstream of Shasta Dam, in northern California. We released two groups of acoustically tagged, juvenile hatchery, late-fall Chinook Salmon to determine how juvenile salmon would distribute and survive. We measured travel times to Shasta Dam, and the number of...

Electricity from wind energy is a major contributor to the strategy to reduce greenhouse gas emissions from fossil fuel use and thus reduce the negative impacts of climate change. Wind energy, like all power sources, can have adverse impacts on wildlife. After nearly 25 years of focused research, these impacts are much better understood, although uncertainty remains. In this report, we...

Access to affordable and reliable energy remains a critical need for people and the economy. To satisfy society’s demand for energy, the United States is expanding access to vast natural resources to produce electricity as well as petroleum and natural gas products. Development of our Nation’s energy resources, however, often conflicts directly with the equally vast fish and wildlife...

This postcard provides details about the U.S. Geological Survey (USGS) Energy and Wildlife Research Annual Report for 2019, which highlights new research on the interactions of energy development with wildlife. Encompassing investigations of conventional and renewable energy development across the United States, from the Arctic Coastal Plain of Alaska to the balmy waters of Florida, the...

Increasing usage of non-medicinal methods (NMMs) to control sea louse infestations on salmon farms has raised questions about whether sea lice may be able to evolve tolerance of NMMs. Of particular concern is the potential for sea lice to evolve freshwater tolerance as a result of freshwater treatments. Wild trout and some juvenile salmonids swim into freshwater to control infestations...

Humpback chub (Gila cypha Miller 1946), found only in the Colorado River Basin, was one of the first species to be given full protection under the Endangered Species Act of 1973. Habitat alterations, such as changes in flow and water temperature caused by dams, and the introduction of nonnative fish have contributed to population declines in humpback chub and other native fish. These...

The impacts of Ceratonova shasta on Klamath River salmonids have been the focus of tremendous research and monitoring over the past decade. Knowledge gained from the various studies has resulted in a growing suite of decision support tools that can be used to predict the prevalence of infection and mortality that can be expected from varying exposure concentrations to C. shasta...