Publications

The overall goal of juvenile salmonid research at The Dalles Dam is to provide data to inform decisions on strategies to improve smolt survival rates at the project. Survival improvement strategies address the three primary passage routes at The Dalles Dam -- spillway, sluiceway, and turbines – with the general intent to increase spill and sluice passage and decrease turbine passage. From 2001, wh

Introduction The Southwestern Willow Flycatcher (Empidonax traillii extimus; hereafter SWFL) is a federally endangered bird (USFWS 1995) that breeds in riparian areas in portions of New Mexico, Arizona, southwestern Colorado, extreme southern Utah and Nevada, and southern California (USFWS 2002). Across this range, it uses a variety of plant species as nesting/breeding habitat, but in all cases

During the winter of 2005-06, we radio and PIT tagged and released 48 juvenile fall Chinook salmon to evaluate over-wintering behavior and dam passage in the lower Snake River, Washington. Fish were released at the upstream end of the Lower Granite Dam forebay in November and December 2005. Fixed radio telemetry detection sites located in forebay and tailrace areas of Lower Granite, Little Goose,

Little is known about the survival of ESA-listed juvenile coho salmon during their seaward migration in the lower Klamath River. In 2006, the Bureau of Reclamation funded a study to estimate the survival of radio-tagged juvenile coho salmon in the Klamath River downstream of Iron Gate Dam. A series of models were evaluated to determine if survival varied between hatchery and wild fish and among se

From 1987 to 1992, we evaluated a fish bypass system at Bonneville Dam Powerhouse 2 on the Columbia River. The survival of subyearling Chinook salmon Oncorhynchus tshawytscha released into the system ranged from 0.774 to 0.911 and was significantly lower than the survival of test fish released into turbines and the area immediately below the powerhouse where bypass system flow reentered the river.

North American green sturgeon, Acipenser medirostris, was petitioned for listing under the Endangered Species Act (ESA). The two questions that need to be answered when considering an ESA listing are; (1) Is the entity a species under the ESA and if so (2) is the "species" in danger of extinction or likely to become an endangered species in the foreseeable future throughout all or a significant po

Recent studies have demonstrated that fish feeds contain significant concentrations of contaminants, many of which can bioaccumulate and bioconcentrate in fish. Organochlorine (OC) contaminants are present in the fish oils and fish meals used in feed manufacture, and some researchers speculate that all fish feeds contain measurable levels of some contaminants. To determine the concentration of con

We examined the survival, tag retention, and growth of Pacific lamprey Lampetra tridentata larvae and macrophthalmia marked with standard-length decimal coded wire tags and exposed to two levels of handling stress. The survival of marked individuals did not differ from that of unmarked individuals at either life stage for the duration of the experiment (56 d). Tag retention was 100% for all treatm

White sturgeon (Acipenser transmontanus) ???95 cm TL were monitored using acoustic and radio telemetry at a large hydroelectric dam (the Dalles Dam) on the Columbia River, during March 2004 through November 2005 to determine timing and routes of passage and to characterize general movements. Transmitters were surgically implanted into 148 fish during the study; 90 were released into the tailrace a

The optimal antenna of transmitters used in small aquatic animals is often a compromise between efficient radio wave propagation and effects on animal behavior. Radio transmission efficiency generally increases with diameter and length of the conductor, but increased antenna length or weight can adversely affect animal behavior. We evaluated the effects of changing antenna length and material on t

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