Ben Letcher is an Ecologist at the USGS Eastern Ecological Science Center in Turners Falls, Massachusetts.
Ben is a population ecologist focusing on stream habitats and science communication.
Professional Experience
1995-now USGS, Ecology section leader, Anadromous Fish Research Center, Turners, Falls, MA, and adjunct professor Department of Natural Resources
Conservation, University of Massachusetts - Amherst1994-1995 Oak Ridge Postdoctoral Fellow (with Dr. David Conover) State University of New York, Stony Brook, NY
1992-1994 Electric Power Research Institute Fellow, North Carolina State University, Raleigh, NC
1990-1992 Wisconsin Sea Grant Fellow, North Carolina State University, Raleigh, NC
1987-1990 URI-USEPA Cooperative Research Fellow, University of Rhode Island, Kingston, RI
1986-1987 Research Assistant, Center for Coastal Studies, Provincetown, MA.
1985-1986 Research Assistant, University of Massachusetts, Amherst, MA.
Education and Certifications
PhD, 1994, NC State, Zoology with statistics and modeling minor
M.S. 1990, URI School of Oceanography, biological option
B.S. 1985, Trinity College, Biology
Science and Products
Filter Total Items: 16
Filter Total Items: 89
Gene-expression signatures of Atlantic salmon's plastic life cycle
How genomic expression differs as a function of life history variation is largely unknown. Atlantic salmon exhibits extreme alternative life histories. We defined the gene-expression signatures of wild-caught salmon at two different life stages by comparing the brain expression profiles of mature sneaker males and immature males, and early migrants and late migrants. In addition to life-stage-spec
Authors
N. Aubin-Horth, B. H. Letcher, H.A. Hofmann
Atlantic salmon (Salmo salar) smolt production: the relative importance of survival and body growth
The complex life history of Atlantic salmon (Salmo salar) coupled with interacting abiotic and biotic factors leads to extreme demographic variability across the species' range. Our goal was to evaluate the relative importance of survival and body growth in determining smolt production across space and time. We used passive integrated transponder tags and capture-mark-recapture analyses to estimat
Authors
G.E. Horton, B. H. Letcher, M.M. Bailey, M.T. Kinnison
Migratory behaviour and survival rates of wild northern Atlantic salmon Salmo salar post-smolts: Effects of environmental factors
To study smolt behaviour and survival of a northern Atlantic salmon Salmo salar population during river descent, sea entry and fjord migration, 120 wild S. salar were tagged with acoustic tags and registered at four automatic listening station arrays in the mouth of the north Norwegian River Alta and throughout the Alta Fjord. An estimated 75% of the post-smolts survived from the river mouth, thro
Authors
J. G. Davidsen, A.H. Rikardsen, E. Halttunen, E.B. Thorstad, F. Okland, B. H. Letcher, J. Skarhamar, T. F. Naesje
Impacts of Low-Flow and Stream-Temperature Changes on Endangered Atlantic Salmon - Current Research
Recent climate studies in New England and the northeastern United States have shown evidence of physical changes over time, including trends toward earlier snowmelt runoff, decreasing river ice, and increasing spring water temperatures. A U.S. Geological Survey (USGS) study funded by the National Global Warming and Wildlife Science Center will be investigating changes in summer low streamflows and
Authors
Robert W. Dudley, Glenn A. Hodgkins, Benjamin H. Letcher
Seasonal variation in size-dependent survival of juvenile Atlantic salmon (Salmo salar): Performance of multistate capture-mark-recapture models
We estimated the magnitude and shape of size-dependent survival (SDS) across multiple sampling intervals for two cohorts of stream-dwelling Atlantic salmon (Salmo salar) juveniles using multistate capture-mark-recapture (CMR) models. Simulations designed to test the effectiveness of multistate models for detecting SDS in our system indicated that error in SDS estimates was low and that both time-i
Authors
B. H. Letcher, G.E. Horton
Movement patterns and study area boundaries: Influences on survival estimation in capture-mark-recapture studies
The inability to account for the availability of individuals in the study area during capture-mark-recapture (CMR) studies and the resultant confounding of parameter estimates can make correct interpretation of CMR model parameter estimates difficult. Although important advances based on the Cormack-Jolly-Seber (CJS) model have resulted in estimators of true survival that work by unconfounding eit
Authors
G.E. Horton, B. H. Letcher
Size and age distributions of Juvenile Connecticut River American shad above Hadley Falls: Influence on outmigration representation and timing
Age- and size-based habitat use and movement patterns of young-of-year American shad in rivers are not well understood. Adult females reach their natal rivers at different times and ascend the river at different rates, which may lead to variation of hatch dates at a single location. Also, shad are serial spawners, so eggs of the same female may be released at different distances from the river mou
Authors
M. J. O'Donnell, B. H. Letcher
Growth rate differences between resident native brook trout and non-native brown trout
Between species and across season variation in growth was examined by tagging and recapturing individual brook trout Salvelinus fontinalis and brown trout Salmo trutta across seasons in a small stream (West Brook, Massachusetts, U.S.A.). Detailed information on body size and growth are presented to (1) test whether the two species differed in growth within seasons and (2) characterize the seasonal
Authors
S.M. Carlson, A.P. Hendry, B. H. Letcher
An efficient smolt trap for sandy and debris-laden streams
Tripod weir and box traps are traditionally used to capture and enumerate out-migrating salmonid smolts in short-term studies and in streams where temporary or portable traps are the only practical option. Although traditional traps can be effective when conditions are ideal, they are often unable to withstand high-discharge events in streams containing a large amount of debris or sandy substrates
Authors
J.G. Scace, B. H. Letcher, J. Noreika
Early discrimination of Atlantic salmon smolt age: Time course of the relative effectiveness of body size and shape
The goal of this study was to test the relative effectiveness of morphological measurements and body size in predicting the smolt age of Atlantic salmon Salmo salar and to determine the time course of body size and shape differences between smolt ages. Analyses were conducted on age-0 to age-2 fish that were stocked as fry in the West Brook, Massachusetts and on laboratory-raised age-0 to age-1 fi
Authors
J.H. Pearlstein, B. H. Letcher, M. Obedzinski
Population response to habitat fragmentation in a stream-dwelling brook trout population
Fragmentation can strongly influence population persistence and expression of life-history strategies in spatially-structured populations. In this study, we directly estimated size-specific dispersal, growth, and survival of stream-dwelling brook trout in a stream network with connected and naturally-isolated tributaries. We used multiple-generation, individual-based data to develop and parameteri
Authors
B. H. Letcher, K.H. Nislow, J.A. Coombs, M. J. O'Donnell, T.L. Dubreuil
A model for estimating passive integrated transponder (PIT) tag antenna efficiencies for interval-specific emigration rates
Our goal was to understand movement and its interaction with survival for populations of stream salmonids at long-term study sites in the northeastern United States by employing passive integrated transponder (PIT) tags and associated technology. Although our PIT tag antenna arrays spanned the stream channel (at most flows) and were continuously operated, we are aware that aspects of fish behavior
Authors
G.E. Horton, T.L. Dubreuil, B. H. Letcher
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- Publications
Filter Total Items: 89
Gene-expression signatures of Atlantic salmon's plastic life cycle
How genomic expression differs as a function of life history variation is largely unknown. Atlantic salmon exhibits extreme alternative life histories. We defined the gene-expression signatures of wild-caught salmon at two different life stages by comparing the brain expression profiles of mature sneaker males and immature males, and early migrants and late migrants. In addition to life-stage-specAuthorsN. Aubin-Horth, B. H. Letcher, H.A. HofmannAtlantic salmon (Salmo salar) smolt production: the relative importance of survival and body growth
The complex life history of Atlantic salmon (Salmo salar) coupled with interacting abiotic and biotic factors leads to extreme demographic variability across the species' range. Our goal was to evaluate the relative importance of survival and body growth in determining smolt production across space and time. We used passive integrated transponder tags and capture-mark-recapture analyses to estimatAuthorsG.E. Horton, B. H. Letcher, M.M. Bailey, M.T. KinnisonMigratory behaviour and survival rates of wild northern Atlantic salmon Salmo salar post-smolts: Effects of environmental factors
To study smolt behaviour and survival of a northern Atlantic salmon Salmo salar population during river descent, sea entry and fjord migration, 120 wild S. salar were tagged with acoustic tags and registered at four automatic listening station arrays in the mouth of the north Norwegian River Alta and throughout the Alta Fjord. An estimated 75% of the post-smolts survived from the river mouth, throAuthorsJ. G. Davidsen, A.H. Rikardsen, E. Halttunen, E.B. Thorstad, F. Okland, B. H. Letcher, J. Skarhamar, T. F. NaesjeImpacts of Low-Flow and Stream-Temperature Changes on Endangered Atlantic Salmon - Current Research
Recent climate studies in New England and the northeastern United States have shown evidence of physical changes over time, including trends toward earlier snowmelt runoff, decreasing river ice, and increasing spring water temperatures. A U.S. Geological Survey (USGS) study funded by the National Global Warming and Wildlife Science Center will be investigating changes in summer low streamflows andAuthorsRobert W. Dudley, Glenn A. Hodgkins, Benjamin H. LetcherSeasonal variation in size-dependent survival of juvenile Atlantic salmon (Salmo salar): Performance of multistate capture-mark-recapture models
We estimated the magnitude and shape of size-dependent survival (SDS) across multiple sampling intervals for two cohorts of stream-dwelling Atlantic salmon (Salmo salar) juveniles using multistate capture-mark-recapture (CMR) models. Simulations designed to test the effectiveness of multistate models for detecting SDS in our system indicated that error in SDS estimates was low and that both time-iAuthorsB. H. Letcher, G.E. HortonMovement patterns and study area boundaries: Influences on survival estimation in capture-mark-recapture studies
The inability to account for the availability of individuals in the study area during capture-mark-recapture (CMR) studies and the resultant confounding of parameter estimates can make correct interpretation of CMR model parameter estimates difficult. Although important advances based on the Cormack-Jolly-Seber (CJS) model have resulted in estimators of true survival that work by unconfounding eitAuthorsG.E. Horton, B. H. LetcherSize and age distributions of Juvenile Connecticut River American shad above Hadley Falls: Influence on outmigration representation and timing
Age- and size-based habitat use and movement patterns of young-of-year American shad in rivers are not well understood. Adult females reach their natal rivers at different times and ascend the river at different rates, which may lead to variation of hatch dates at a single location. Also, shad are serial spawners, so eggs of the same female may be released at different distances from the river mouAuthorsM. J. O'Donnell, B. H. LetcherGrowth rate differences between resident native brook trout and non-native brown trout
Between species and across season variation in growth was examined by tagging and recapturing individual brook trout Salvelinus fontinalis and brown trout Salmo trutta across seasons in a small stream (West Brook, Massachusetts, U.S.A.). Detailed information on body size and growth are presented to (1) test whether the two species differed in growth within seasons and (2) characterize the seasonalAuthorsS.M. Carlson, A.P. Hendry, B. H. LetcherAn efficient smolt trap for sandy and debris-laden streams
Tripod weir and box traps are traditionally used to capture and enumerate out-migrating salmonid smolts in short-term studies and in streams where temporary or portable traps are the only practical option. Although traditional traps can be effective when conditions are ideal, they are often unable to withstand high-discharge events in streams containing a large amount of debris or sandy substratesAuthorsJ.G. Scace, B. H. Letcher, J. NoreikaEarly discrimination of Atlantic salmon smolt age: Time course of the relative effectiveness of body size and shape
The goal of this study was to test the relative effectiveness of morphological measurements and body size in predicting the smolt age of Atlantic salmon Salmo salar and to determine the time course of body size and shape differences between smolt ages. Analyses were conducted on age-0 to age-2 fish that were stocked as fry in the West Brook, Massachusetts and on laboratory-raised age-0 to age-1 fiAuthorsJ.H. Pearlstein, B. H. Letcher, M. ObedzinskiPopulation response to habitat fragmentation in a stream-dwelling brook trout population
Fragmentation can strongly influence population persistence and expression of life-history strategies in spatially-structured populations. In this study, we directly estimated size-specific dispersal, growth, and survival of stream-dwelling brook trout in a stream network with connected and naturally-isolated tributaries. We used multiple-generation, individual-based data to develop and parameteriAuthorsB. H. Letcher, K.H. Nislow, J.A. Coombs, M. J. O'Donnell, T.L. DubreuilA model for estimating passive integrated transponder (PIT) tag antenna efficiencies for interval-specific emigration rates
Our goal was to understand movement and its interaction with survival for populations of stream salmonids at long-term study sites in the northeastern United States by employing passive integrated transponder (PIT) tags and associated technology. Although our PIT tag antenna arrays spanned the stream channel (at most flows) and were continuously operated, we are aware that aspects of fish behaviorAuthorsG.E. Horton, T.L. Dubreuil, B. H. Letcher - Software