Publications

Marine and freshwater plastic pollution is a challenging issue receiving large amounts of research and media attention. Yet, few studies have documented the impact of microplastic ingestion to aquatic organisms. In the Pacific Northwest, Chinook salmon are a culturally and commercially significant fish species. The presence of marine and freshwater microplastic pollution is well...

Anthropogenic eutrophication contributes to harmful blooms of cyanobacteria in freshwater ecosystems worldwide. In Upper Klamath Lake, Oregon, massive blooms of Aphanizomenon flos-aquae and smaller blooms of other cyanobacteria are associated with cyanotoxins, hypoxia, high pH, high concentrations of ammonia, and potentially hypercapnia. Recovery of the endangered Lost River sucker...

Executive Summary Populations of federally endangered Lost River (Deltistes luxatus) and shortnose suckers (Chasmistes brevirostris) in Upper Klamath Lake, Oregon, and Clear Lake Reservoir (hereinafter Clear Lake), California, are experiencing long-term decreases in abundance. Upper Klamath Lake populations are decreasing not only because of adult mortality, which is relatively low, but...

Executive Summary Native steelhead (anadromous form of rainbow trout [Oncorhynchus mykiss]) and bridgelip sucker (Catostomus columbianus) were historically used by the Kah-miltpah (Rock Creek) Band for sustenance, trade, and traditional practices in Rock Creek, a tributary to the Columbia River in southeastern Washington State. Rock Creek flows south to the Columbia River at river...

Brazilian elodea (Egeria densa) is an invasive freshwater plant that demonstrates widespread ecological impacts in freshwater ecosystems and causes substantial economic damage. Here, we developed an environmental DNA assay for detection of E. densa to provide resource managers with a tool for early detection, identification, and monitoring of invasive populations.

Piscine orthoreovirus genotype 1 (PRV‐1) is the causative agent of heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon (Salmo salar L.). The virus has also been found in Pacific salmonids in western North America, raising concerns about the risk to native salmon and trout. Here, we report the results of laboratory challenges using juvenile Chinook salmon, coho salmon...

Within the Big Bend region of the northeastern Gulf of Mexico, one of the least developed coastlines in the continental USA, intertidal and subtidal populations of eastern oyster Crassostrea virginica (hereafter referred to as “oyster”) are a critical ecosystem and important economic constituent. We assessed trends in intertidal oyster populations, river discharge, and commercial fishing...

Executive Summary A 2-year radiotelemetry study was completed to monitor the movements of adult winter steelhead (Oncorhynchus mykiss) in the upper Cowlitz River Basin. A reintroduction program was established to restore healthy and harvestable populations of steelhead because volitional access to the area was blocked in the 1960s after construction of dams in the lower river. A trap-and...

Growth during the early marine critical period is positively associated with survival and recruitment for Pacific salmon Oncorhynchus spp., so it is important to understand how certain foraging strategies may bolster growth in estuarine and marine environments. To elucidate how spatiotemporal and demographic differences in diet contribute to growth rate variability, we analyzed stomach...

A study was conducted in the lower Yakima River, Washington, during June–October 2019 to evaluate water temperature effects on adult sockeye salmon (Oncorhynchus nerka) behavior. A total of 60 sockeye salmon adults were tagged with radio transmitters and monitored during the study. Fourteen of the fish were collected and tagged at Prosser Dam in late June and the remainder were collected...

Because fish that enter the interior Delta have poorer survival than those emigrating via the Sacramento River, understanding the mechanisms that drive entrainment rates at side channel junctions is critically important for the management of imperiled juvenile salmon. Here, we implement a previously proposed process-based conceptual model to study entrainment rates based on three linked...

We will investigate fish health factors that may be contributing to the failed recovery of Pacific herring populations in Prince William Sound. Field samples will provide infection and disease prevalence data from Prince William Sound and Sitka Sound that will inform the ASA model, serological data that will indicate the prior exposure history and future susceptibility of herring to VHS...