Electrofishing is a sampling tool commonly used by fisheries researchers. While much is known about the effects of electroshock on fish physiology, consequences to the immune system and disease progression have not received attention. To understand the effects of electroshock on immune function we undertook a comparison of electroshock and...
Environmental factors such as chemical contamination can have immunomodulatory effects on the immune response of fish and may be contributing to the decline in salmonid populations by augmenting disease susceptibility. Xenobiotics can interfere with the immune system at several levels of complexity, and different immune cells and processes have variable...
Stress, including extreme or rapidly changing temperatures, are known to have deleterious effects on fish health and physiology. This thesis examines the combined effects of elevated acclimation temperature and acute handling stress on the number of antibody producing cells, plasma lysozyme concentrations, and the number of pronephric leukocytes in juvenile...
In this thesis, we examined the effects of the exposures to anthropogenic pollutants on the fish, primarily juvenile chinook salmon, immune system using newly and recently developed immune assays. In addition, we developed a new assay for measuring immunocompetence of fish. In the first chapter, the Alamar Blue assay was...
Wild populations of fish are faced with a multitude of stressors, which may include human interaction, toxins, and disease. Benzo(a)pyrene (BaP), a known carcinogen and immunotoxin, has been reported in the stomach contents of juvenile chinook salmon, Oncorhynchus tshawytscha, in urban waterways. We investigated the impact of chronic dietary exposure...
Annual rates of prespawn mortality (PSM) in adult Chinook salmon (Oncorhynchus tshawytscha) trapped and transported upstream of dams in the Willamette River basin are high (often >40%) and could limit the ability to restore natural populations of spring Chinook salmon if not reduced. Improvements at the U.S. Army Corps of...
Hatcheries are used to produce salmon to augment the number of fish available for harvest, and to supplement wild populations that may be threatened with extinction. Although traditional hatchery rearing methods can produce many fish, they can pose risk to wild populations because they tend to produce salmon with lower...
Marine heatwaves have become more common over the past several years. The 2014-2015 ‘warm blob’ had profound effects on marine ecosystems in the Northeast Pacific. Given the particular habitat needs of Chinook Salmon (Oncorhynchus tshawytscha) we wanted to examine the impacts of the heatwave on Chinook depth distribution. We examined...