Rebecca A. Buchanan

Rebecca A. Buchanan
University of Washington Seattle | UW · School of Aquatic and Fishery Sciences

Doctor of Philosophy

About

45
Publications
7,543
Reads
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394
Citations
Citations since 2016
23 Research Items
256 Citations
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201620172018201920202021202201020304050
Introduction
I am the Co-Director of the University of Washington’s Columbia Basin Research, and Senior Research Scientist in the UW School of Aquatic and Fishery Sciences. My interest is developing and communicating quantitative methods to support science-based management of hydropower and water resources for fish and human communities. I specialize in spatially- and temporally-branching release-recapture models for salmon and steelhead migrations in rivers, past dams, and in estuaries.
Additional affiliations
July 2015 - present
University of Washington Seattle
Position
  • Senior Researcher
Description
  • I develop quantitative methods and tools to support managers and researchers in science-based management of hydropower projects, water resources, and fish communities. My specialty is multistate release-recapture models for juvenile and adult salmonid migration in rivers, past dams, and through estuaries. I also assist managers and researchers in design and analysis of their tagging studies, and lead workshops in survival analysis for salmon researchers.
January 2007 - June 2015
University of Washington Seattle
Position
  • Researcher
Description
  • I developed quantitative models and tools to monitor salmonid migration in the Columbia Basin and the Sacramento-San Joaquin River delta, lead workshops in survival analysis for managers and analysts, wrote journal articles, and presented findings at research conferences.
January 2006 - January 2007
University of Washington Seattle
Position
  • PostDoc Position
Description
  • I developed release-recapture methods to monitor route-specific survival of juvenile and adult salmon in the Columbia River Basin, wrote journal articles, and presented at scientific meetings.
Education
September 2000 - December 2005
University of Washington Seattle
Field of study
  • Quantitative Ecology and Resource Management
August 1996 - June 1998
Syracuse University
Field of study
  • Mathematics Education
August 1991 - May 1995
Bryn Mawr College
Field of study
  • Mathematics

Publications

Publications (45)
Technical Report
Full-text available
This document is a compilation and synthesis of the many references relevant to tag predation in salmonid studies in the Central Valley, as well as pertinent studies outside the region. There are four main sections: (1) background, (2) categorization tables, (3) annotated bibliography, and (4) appendices. Our aim is to provide researchers in the Ce...
Article
Effective management of natural resources and migratory fish populations depends on understanding the relationship between life cycle parameters, management decisions, and environmental conditions. Yet the difficulty of data collection can result in small or non‐representative data sets and thus limit the accuracy and utility of modeling results. T...
Article
Full-text available
Background Acoustic telemetry is a powerful tool for studying fish behavior and survival that relies on the assumption that tag detection reflects the presence of live study subjects. This assumption is violated when tag signals continue to be recorded after consumption by predators. When such tag predation is possible, it is necessary for research...
Preprint
Full-text available
Acoustic telemetry is a powerful tool for studying fish behavior and survival that relies on the assumption that tag detection reflects the presence of live study subjects. This assumption is violated in cases where tag signals continue to be recorded after predators have consumed tagged study subjects. When such tag predation is possible, it becom...
Article
Southern salmon populations face increased risk from a warming climate. New analysis of salmon ear bones shows outsized reliance on rarely used cold-water habitat for population survival through drought years — habitat that is expected to shrink under climate change.
Article
Extirpation of the Central Valley spring-run Chinook Salmon ESU (Oncorhynchus tshawytscha) from the San Joaquin River is emblematic of salmonid declines across the western seaboard of the United States. Habitat restoration and fish reintroduction efforts are ongoing, but recent telemetry studies have revealed low outmigration survival of juveniles...
Preprint
Full-text available
Extirpation of the Central Valley spring-run Chinook Salmon ESU (Oncorhynchus tshawytscha) from the San Joaquin River is emblematic of salmonid declines across the Pacific Northwest. Habitat restoration and fish reintroduction efforts are ongoing, but recent telemetry studies have revealed low outmigration survival of juveniles to the ocean. Previo...
Experiment Findings
Full-text available
All VAMP reports are available online at http://tuolumnerivertac.com/documents.htm
Experiment Findings
Full-text available
All VAMP reports are available online at http://tuolumnerivertac.com/documents.htm
Experiment Findings
Full-text available
All VAMP reports are available online at http://tuolumnerivertac.com/documents.htm
Article
Juvenile steelhead are exposed to numerous threats in heterogeneous, estuarine environments, yet understanding of survival patterns and processes during this migratory stage is often limited by studies that use surrogate species or are restricted in duration and spatial specificity. Lack of detailed survival information in this critical migratory s...
Article
Full-text available
Survival of juvenile fall-run Chinook Salmon Oncorhynchus tshawytscha from the San Joaquin River (SJR) during their migration through the Sacramento-San Joaquin Delta of California has been low in recent years, and there is uncertainty about the role of river flow on survival. Five years (2010–2014) of acoustic telemetry data from juvenile hatchery...
Technical Report
Full-text available
Predation by non-native fishes in the McNary Reservoir and Hanford Reach of the Columbia River reduces the productivity of anadromous fish populations that rear in and migrate through this area. Recent work shows very low juvenile Chinook salmon survival, high consumption rates of juvenile salmonids by smallmouth bass and walleye, and high non-nati...
Article
Survival of juvenile fall‐run Chinook Salmon Oncorhynchus tshawytscha through the San Joaquin River Delta of California, USA, has been low for most estimates since 2002, and has been consistently low since 2010. From 2010 through 2015, annual estimates of the probability of surviving through the Delta (from Mossdale to Chipps Island, approximately...
Article
Full-text available
Background Multistate release–recapture models are used to study the movements and survival of animals when multiple migration pathways exist. Model complexity increases exponentially as the number of possible migration pathways increases. ResultsProgram Branch was developed as freeware to allow users to construct multistate release–recapture model...
Article
Full-text available
As juvenile salmon enter the Sacramento-San Joaquin River Delta ("the Delta") they disperse among its complex channel network where they are subject to channel-specific processes that affect their rate of migration, vulnerability to predation, feeding success, growth rates, and ultimately, survival. In the decades before 2006, tools available to qu...
Article
Full-text available
Survival of juvenile anadromous Pacific salmonids from their earliest age of seaward movement (“out-migration”) through the tributaries that connect their rearing grounds to larger-order rivers (“cohort survival”) is an important yet often unmonitored factor in the complex life history of these species. Populations with variable age at out-migratio...
Article
Full-text available
Background: Acoustic-tag studies with their high to very high detection rates defy traditional statistical wisdom regarding analysis of tagging studies. Conventional wisdom has been to use a parsimonious model with the fewest parameters that adequately describes the data to estimate survival parameters in release-recapture studies in order to find...
Article
The survival of juvenile Chinook Salmon through the lower San Joaquin River and Sacramento–San Joaquin River Delta in California was estimated using acoustic tags in the spring of 2009 and 2010. The focus was on route use and survival within two major routes through the Delta: the San Joaquin River, which skirts most of the interior Delta to the ea...
Conference Paper
The advent of small acoustic telemetry tags has greatly expanded our ability to track movements of juvenile salmonids as they migrate to the ocean. We are now able to track tagged fish as they move through complex environments such as river deltas and estuaries, and can begin to address such questions as: What routes do salmon smolts take through d...
Article
A multistate mark-recapture (MSMR) model of the adult salmonid migration through the lower Columbia River and into the Snake River was developed, designed for radiotelemetry detections at dams and tributary mouths. The model focuses on upstream-directed travel, with states determined from observed fish movement patterns indicating directed upstream...
Article
Full-text available
Data from live and dead fish counts at salmonid spawning areas have been used for decades to estimate stream residence time. Simulation studies indicate that the peak-to-peak and median-to-median estimates of stream residence time will have at least a 50% negative bias under the best of circumstances. A new estimation technique called the “expectat...
Technical Report
Full-text available
To determine whether the Juvenile Salmon Acoustic Telemetry System (JSATS) technology was suitable for conducting subyearling Chinook salmon survival studies in the Priest Rapids Project, we tagged 546 Priest Rapids Hatchery-origin subyearling fall Chinook salmon (mean fork length = 104 mm) with a newly developed delayed-start acoustic transmitter...
Article
Full-text available
A total of 1154 acoustic-tagged subyearling fall Chinook salmon (Oncorhynchus tshawytscha) were monitored during their movement through Lower Monumental Reservoir, Snake River, Washington, USA. A release–recapture design was developed to partition their fates into migration, delayed migration (i.e., holdover or temporary residualization), and morta...
Article
Full-text available
The survival of very small fish can have a major impact on the dynamics of fisheries stocks. Numerous marking techniques have been developed or adapted to small fish in order to investigate either early life histories or small-sized species. Some techniques provide batch marks, while others provide individually unique identification with or without...
Article
Full-text available
Previous methods of estimating route-specific passage and survival probabilities for anadromous salmonids past hydroelectric dams have often failed because of faulty assumptions. We present a robust, multiple-release model that combines release–recapture methods that are known to solve parts of the overall problem. Release 1 allows estimation of ro...
Technical Report
Full-text available
Juvenile Snake River fall Chinook salmon (Oncorhyncus tshawytscha) typically emigrate as age-0 fish from the Snake River to the Pacific Ocean between early June and September, with the majority of the fish swimming seaward between mid-June and mid-July. The fish emigrating later in the season have a higher likelihood of remaining in freshwater for...
Article
Full-text available
Since 1987, millions of juvenile salmonids (smolts; Oncorhynchus species) in the Snake and upper Columbia rivers have been tagged with Passive Integrated Transponder (PIT) tags, and detected at hydroelectric projects as theymigrate downriver to the Pacific Ocean. Since the late 1990s, detection of PIT-tagged adults has been possible at some dams. E...
Article
The finite annual rate of population increase (λ) is a fundamental demographic parameter that characterizes the relative annual change in animal numbers. Uncertainty in the estimation of λ from demographic population viability analyses (PVAs) has been largely limited to sensitivity analysis, calculating a pseudo-distribution for λˆ using Monte Carl...
Article
Full-text available
Smolt transportation is a major mitigation strategy in the Columbia River hydrosystem, yet measures of its effects on adult return rates are often unclear. Managers use a variety of transportation effect measures that need to be clearly defined and easy to understand. We develop eight alternative transportation effect measures based on a release–re...
Article
Ranked set sampling (RSS) can be a useful environmental sampling method when measurement costs are high but ranking costs are low. RSS estimates of the population mean can have higher precision than estimates from a simple random sample (SRS) of the same size, leading to potentially lower sampling costs from RSS than from SRS for a given precision....
Article
Full-text available
The combined juvenile and adult detections of Snake River yearling Chinook salmon Oncorhynchus tshawytscha implanted with passive integrated transponder tags migrating through the hydroelectric facilities in the Federal Columbia River Power System were analyzed using the ROSTER statistical release–recapture model. This model was used to estimate th...
Article
The combined juvenile and adult detection histories of PIT-tagged wild salmonids migrating through the Federal Columbia River Power System (FCRPS) were analyzed using the ROSTER (River-Ocean Survival and Transportation Effects Routine) statistical release-recapture model. This model, implemented by software Program ROSTER, was used to estimate surv...
Article
The U.S. Army Corps of Engineers Portland District (CENWP) funds numerous evaluations of fish passage and survival on the Columbia River. In 2007, the CENWP asked Pacific Northwest National Laboratory to conduct an acoustic telemetry study to estimate the survival of juvenile Chinook salmon passing the spillway at Bonneville Dam. This report docume...
Article
In 2005, the University of Washington developed a new statistical model to analyze the combined juvenile and adult detection histories of PIT-tagged salmon migrating through the Federal Columbia River Power System (FCRPS). This model, implemented by software Program ROSTER (River-Ocean Survival and Transportation Effects Routine), has been used to...
Article
Full-text available
Ship wakes produced by deep-draft vessels transiting the lower Columbia River have been observed to cause stranding of juvenile salmon. Proposed deepening of the Columbia River navigation channel has raised concerns about the potential impact of the deepening project on juvenile salmon stranding. The Portland District of the U.S. Army Corps of Engi...
Article
Full-text available
Thesis (Ph. D.)--University of Washington, 2005. Release-recapture models for two types of tagging data from migrating salmonids in the Columbia and Snake rivers are presented. The first model uses both juvenile and adult PIT-tag data to analyze the seaward and spawning migrations through the hydrosystem. This branching model accommodates transport...

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Projects

Projects (4)
Project
Development of a Standard Operating Procedure (SOP) for diagnosing and handling tag predation in acoustic telemetry studies of emigrating juvenile salmonids in the Sacramento–San Joaquin River Delta. This project involves: (1) analyzing existing telemetry data sets of predatory fishes to characterize movement patterns by species, season, and regions; (2) developing analytical approaches to reduce uncertainty, subjectivity, and effort of analysis in salmonid acoustic telemetry studies; and (3) standardizing methods and providing software tools for diagnosing detections of predated tags in future studies.
Archived project
Multi-year experimental management program designed to protect juvenile Chinook salmon migrating from the San Joaquin River through the Sacramento-San Joaquin Delta (California). All VAMP reports are available online at http://tuolumnerivertac.com/documents.htm