Publications

This report presents the results for two sampling periods (April 2008 and July 2008) during a 4-year monitoring program to characterize selenium concentrations in selected irrigation drains flowing into the Salton Sea, California. Total selenium, selenium species (dissolved selenite, selenate, organoselenium), and total suspended solids were determined in water samples and total selenium...

A study to estimate the effects of Iron Gate Dam discharge on ESA-listed juvenile coho salmon during their seaward migration to the ocean was begun in 2005. Estimates of survival through various reaches of river downstream from the dam were completed in 2006, 2007, and 2008 as part of this process. This report describes the estimates of survival during 2008, and is a complement to...

Parvicapsula minibicornis is a myxosporean parasite that is associated with disease in Pacific salmon during their freshwater life history phase. This study reports the development of a quantitative (real-time) polymerase chain reaction (QPCR) to detect P. minibicornis DNA. The QPCR assay targets the 18S ribosomal subunit gene. A plasmid DNA control was developed to calibrate cycle...

No abstract available.

Numerous state and federal agencies are increasingly concerned with the rapid expansion of invasive, noxious weeds across the United States. Herbicides are frequently applied as weed control measures in forest and rangeland ecosystems that frequently overlap with critical habitats of threatened and endangered fish species. However, there is little published chronic toxicity data for...

Concerns about infectious diseases in fish used for research have risen along with the dramatic increase in the use of fish as models in biomedical research. In addition to acute diseases causing severe morbidity and mortality, underlying chronic conditions that cause low-grade or subclinical infections may confound research results. Here we present recommendations and strategies to...

Host specificity is a phenomenon exhibited by all viruses. For the fish rhabdovirus infectious hematopoietic necrosis virus (IHNV), differential specificity of virus strains from the U and M genogroups has been established both in the field and in experimental challenges. In rainbow trout (Oncorhynchus mykiss), M IHNV strains are consistently more prevalent and more virulent than U IHNV...

Members of the bacterial genus Francisella are highly virulent and infectious pathogens. New models to study Francisella pathogenesis in evolutionarily distinct species are needed to provide comparative insight, as the mechanisms of host resistance and pathogen virulence are not well understood. We took advantage of the recent discovery of a novel species of Francisella to establish a...

This study was conducted to better understand the habitat requirements and environmental limiting factors of Syncaris pacifica, the California freshwater shrimp. This federally listed endangered species is native to perennial lowland streams in a few watersheds in northern California. Field sampling occurred in Lagunitas and Olema creeks at seasonal intervals from February 2003 to...

The Hanford Reach is one of the few remaining unimpounded sections of the Columbia River. However, because of flow management at upstream dams, there are often large fluctuations in water level. To determine how environmental conditions might affect age-0 resident fishes in the Hanford Reach, we evaluated species composition, distribution, abundance, and standard lengths of larval and...

A rapid staining procedure for detection of recent skin and fin injuries was tested in juvenile Chinook salmon Oncorhynchus tshawytscha. Immersion of anesthetized fish for 1 min in aerated aqueous solutions of the synthetic food dye fast green FCF (Food Green 3) at concentrations of 0.1 to 0.5% produced consistent and visible staining of integumental injuries. A 0.1% fast green...

Epizootics of viral erythrocytic necrosis (VEN) occurred among juvenile Pacific herring Clupea pallasii in Skagit Bay, Puget Sound, Washington, during 2005-2007 and were characterized by high prevalences and intensities of cytoplasmic inclusion bodies within circulating erythrocytes. The prevalence of VEN peaked at 67% during the first epizootic in October 2005 and waned to 0% by August...