Publications

Extensive mortalities of adult coho salmon (Oncorhynchus kisutch), often called “Urban Runoff Mortality Syndrome” (URMS), have been documented during the fall in creeks where water quality has been degraded by roadway runoff. The primary cause of mortality is 6PPD-quinone (6PPDQ; N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine quinone)–an ozone transformation product that forms on all...

Black bass (Micropterus spp.) are the most important warmwater game fishes in the United States. They have high socioeconomic and recreational value and support an important aquaculture industry. Since 2008, fisheries managers have been reporting the observation of hyperpigmented melanistic lesions (HPMLs) on smallmouth bass (M. dolomieu) in different ecoregions of the United States...

Emergent viral diseases remain a critical obstacle to welfare across landscapes and species, encompassing humans, wildlife, and agriculture. Following a jump to a novel host, the severity of disease resulting from infection is a critical determinant of the overall emergent pathogen threat. Conventional wisdom posits that virulence, defined here as host mortality, attenuates to...

We examined the progression of gas bubble trauma (GBT) and associated mortality in sculpin (Cottus spp.), threespine stickleback (Gasterosteus aculeatus), and Northern pikeminnow (Ptychocheilus oregonensis) exposed to three levels of total dissolved gas (TDG; 120, 125, and 130% saturation) in laboratory experiments. Sculpin were most sensitive to elevated TDG followed by stickleback and...

Zebra (Dreissena polymorpha) and quagga (Dreissena rostriformis bugensis) mussels have caused the highest economic costs among all aquatic invasive species in the United States (Washington Department of Fish and Wildlife (WDFW) 2016). Officials estimate that if zebra and quagga mussels become established in Washington, removal and management costs could exceed $100 million annually (WDFW...

Fish passage development is a priority at Tieton Dam, on the Tieton River in Washington state, because passage options were not included when the dam was constructed nearly 100 years ago. To inform downstream passage design, we conducted a study to evaluate migration and near-dam behavior of juvenile salmon. The primary goal of the study was to determine how fish approached the dam and...

The recovery of endangered fish requires an understanding of the sources of mortality that regulate population dynamics. We estimated avian predation rates on passive integrated transponder tagged (PIT) adult and juvenile Lost River Suckers (Deltistes luxatus), Shortnose Suckers (Chasmistes brevirostris), Klamath Largescale Suckers (C. snyderi), and juvenile Chinook Salmon (Oncorhynchus

Nervous necrosis virus (NNV) causes a neurologic disease in a wide range of marine fish and poses serious disease risks to marine aquaculture worldwide. Little is known about the presence of NNV along the Atlantic coast of the United States, aside from the presence of barfin flounder nervous necrosis virus (BFNNV) in coldwater species in the northern part of this range. Herein we...

More than 10 years following the onset of the sea star wasting disease (SSWD) epidemic, affecting over 20 asteroid species from Mexico to Alaska, the causative agent has been elusive. SSWD killed billions of the most susceptible species, sunflower sea stars (Pycnopodia helianthoides), initiating a trophic cascade involving unchecked urchin population growth and the widespread loss of...

We performed a diagnostic disease investigation on a wild smallmouth bass (Micropterus dolomieu) with skin ulcers that was collected from Lake Oahe, South Dakota, following reports from anglers of multiple fish with similar lesions. Gross and histologic lesions of ulcerative dermatitis, myositis, and lymphocytolysis within the spleen and kidneys were consistent with largemouth bass virus...

Global restoration and conservation of freshwater biodiversity are represented in practice by works such as the Klamath River Renewal Project (KRRP), the largest dam removal and river restoration in the United States, which has reconnected 640 river kilometers. With dam removals, many biological outcomes remain understudied due to a lack of pre-impact data and complex ecosystem recovery...

Polycyclic aromatic hydrocarbons (PAHs) are toxic constituents of crude oil that can induce cardiac dysfunction and vision impairment in early life stage (ELS) fishes. However, it is currently unknown whether visual impairments are independent effects or if they result from underlying PAH cardiotoxicity. To better understand this mechanism, microinjection of microRNA 133b (miR133b) was...