David A Hewitt, Ph.D.
David Hewitt is a Research Ecologist at the Wetland and Aquatic Research Center. Previously, David was a Research Fish Biologist at the Western Fisheries Research Center where he provided guidance for the research and monitoring program for two endangered catostomids in the Upper Klamath Basin of Oregon and California.
Related Content:
Hewitt, D. A., V. N. Ut, M. E. Andersen, J. W. Beeman, H. C. Patricio, S. M. Ainsley, S. Ounboundisane, D. Demko, and C. Conzelmann. 2015. Collaborative research of Mekong River fishes. Global Conference on Inland Fisheries, FAO, Rome, Italy. [Poster]
Education and Certifications
Ph.D. 2009. Marine Science (Fisheries Science/Crustacean Ecology), Virginia Institute of Marine Science, College of William and Mary, Advisor: Dr. Rom Lipcius
M.S. 2003. Fisheries and Wildlife Sciences (Minor in Statistics), North Carolina State University, Department of Zoology, North Carolina Cooperative Fish and Wildlife Research Unit, Advisor: Hightower
B.S. 2000. Fisheries Science, Virginia Tech, Department of Fisheries and Wildlife Sciences, College of Natural Resources, Blacksburg, VA
Science and Products
Filter Total Items: 29
Avian predation on juvenile and adult Lost River and Shortnose Suckers: An updated multi-predator species evaluation
Previous research suggests that predation by piscivorous colonial waterbirds may negatively influence the survival of Lost River Suckers (LRS) Deltistes luxatus and Shortnose Suckers (SNS) Chasmistes brevirostris in the Upper Klamath Basin (UKB), USA. However, estimates of predation from past studies, which were based on suckers with PIT tags, represent minimum estimates of sucker...
Authors
Allen Evans, Quinn Payton, Nathan V Banet, Bradley M. Cramer, Caylen Kelsey, David A. Hewitt
Distribution of bull trout (Salvelinus confluentus) in conjunction with habitat and trout assemblages in creeks within the Klamath Basin, Oregon 2010–16
Bull trout (Salvelinus confluentus) in the Klamath Basin are on the southernmost border of the range of the species, where threats are most severe and where bull trout are most imperiled. In their recovery plan the U.S. Fish and Wildlife Service (2015, https://ecos.fws.gov/ecp/report/species-with-recovery-plans) suggested that Klamath Basin bull trout are at increased risk of extirpation...
Authors
Barbara A. Martin, Nolan Banish, David A. Hewitt, Brian S. Hayes, Amari Dolan-Caret, Alta C. Harris, Caylen Kelsey
Avian predation of juvenile Lost River and Shortnose Suckers in Upper Klamath Lake: An assessment of Sucker assisted rearing program releases during 2018–2020
To bolster recruitment in Endangered Species Act (ESA) listed Lost River Suckers (Deltistes luxatus) and Shortnose Suckers (Chasmistes brevirostris) in the Upper Klamath Basin (UKB), the U.S. Fish and Wildlife Service (USFWS) and its partners have implemented the Sucker Assisted Rearing Program (SARP). As part of this program, juvenile suckers were reared in captivity, implanted with...
Authors
Allen Evans, Quinn Payton, Nathan V Banet, Bradley M. Cramer, Caylen Kelsey, David A. Hewitt
Spatial and temporal distribution of radio-tagged Lost River (Deltistes luxatus) and shortnose (Chasmistes brevirostris) suckers in Clear Lake Reservoir and associated spawning tributaries, Northern California, 2015–17
Executive SummaryData from a multi-year radio telemetry study were used to assess seasonal distribution patterns for two long-lived, federally endangered catostomids across substantially different water conditions in Clear Lake Reservoir, northern California. Lost River (Deltistes luxatus) and shortnose (Chasmistes brevirostris) suckers, two species endemic to the Klamath Basin, were...
Authors
Nathan Banet, David A. Hewitt, Amari Dolan-Caret, Alta C. Harris
Dynamics of endangered sucker populations in Clear Lake Reservoir, California
Executive SummaryIn collaboration with the Bureau of Reclamation, the U.S. Geological Survey began a consistent monitoring program for endangered Lost River suckers (Deltistes luxatus) and shortnose suckers (Chasmistes brevirostris) in Clear Lake Reservoir, California, in fall 2004. The program was intended to improve understanding of the Clear Lake Reservoir populations because they are...
Authors
David A. Hewitt, Brian S. Hayes, Alta C. Harris, Eric C. Janney, Caylen M. Kelsey, Russell W. Perry, Summer M. Burdick
Effects of harmful algal blooms and associated water-quality on endangered Lost River and shortnose suckers
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...
Authors
Summer M. Burdick, David A. Hewitt, Barbara A. Martin, Liam N. Schenk, Stewart A. Rounds
Characterization of the genetic structure of four sucker species in the Klamath River. Final Report
Four species of suckers (family Catostomidae) inhabit the Klamath River Basin of Oregon and California: Lost River suckers (LRS; Deltistes luxatus), shortnose suckers (SNS; Chasmistes brevirostris), Klamath largescale suckers (KLS; Catostomus snyderi), and Klamath smallscale suckers (KSS; Catostomus rimiculus). All but Klamath smallscale suckers are endemic and restricted to the Klamath...
Authors
Matt Smith, Jennifer Von Bargen, Christian A. Smith, Michael A. Miller, Josh Rasmussen, David A. Hewitt
Monitoring of endangered Klamath Basin suckers translocated from Lake Ewauna to Upper Klamath Lake, Oregon, 2014−2017
Data from a 4-year capture and transport program were used to assess translocation as a management strategy for two long-lived, federally endangered catostomids in the Upper Klamath Basin, Oregon. Lost River (Deltistes luxatus) and shortnose (Chasmistes brevirostris) suckers, two species endemic to the Klamath Basin, were translocated from Lake Ewauna to Upper Klamath Lake in each of 4...
Authors
Nathan V. Banet, David A. Hewitt
Status and trends of adult Lost River (Deltistes luxatus) and shortnose (Chasmistes brevirostris) sucker populations in Upper Klamath Lake, Oregon, 2017
Executive SummaryData from a long-term capture-recapture program were used to assess the status and dynamics of populations of two long-lived, federally endangered catostomids in Upper Klamath Lake, Oregon. Lost River suckers (LRS; Deltistes luxatus) and shortnose suckers (SNS; Chasmistes brevirostris) have been captured and tagged with passive integrated transponder (PIT) tags during...
Authors
David A. Hewitt, Eric C. Janney, Brian S. Hayes, Alta C. Harris
Status and trends of adult Lost River (Deltistes luxatus) and shortnose (Chasmistes brevirostris) sucker populations in Upper Klamath Lake, Oregon, 2015
Executive SummaryData from a long-term capture-recapture program were used to assess the status and dynamics of populations of two long-lived, federally endangered catostomids in Upper Klamath Lake, Oregon. Lost River suckers (LRS; Deltistes luxatus) and shortnose suckers (SNS; Chasmistes brevirostris) have been captured and tagged with passive integrated transponder (PIT) tags during...
Authors
David A. Hewitt, Eric C. Janney, Brian S. Hayes, Alta C. Harris
Colonial waterbird predation on Lost River and Shortnose suckers in the Upper Klamath Basin
We evaluated predation on Lost River Suckers Deltistes luxatus and Shortnose Suckers Chasmistes brevirostris by American white pelicans Pelecanus erythrorhynchos and double-crested cormorants Phalacrocorax auritus nesting at mixed-species colonies in the Upper Klamath Basin of Oregon and California during 2009–2014. Predation was evaluated by recovering (detecting) PIT tags from tagged...
Authors
Allen F. Evans, David A. Hewitt, Quinn Payton, Bradley M. Cramer, Ken Collis, Daniel D. Roby
The logic of comparative life history studies for estimating key parameters, with a focus on natural mortality rate
There are a number of key parameters in population dynamics that are difficult to estimate, such as natural mortality rate, intrinsic rate of population growth, and stock-recruitment relationships. Often, these parameters of a stock are, or can be, estimated indirectly on the basis of comparative life history studies. That is, the relationship between a difficult to estimate parameter...
Authors
John M Hoenig, Amy Y.-H. Then, Elizabeth A. Babcock, Norman G. Hall, David A. Hewitt, Sybrand A. Hesp
Non-USGS Publications**
Hewitt, D. A., and J. M. Hoenig. 2005. Comparison of two approaches for estimating natural mortality based on longevity. Fishery Bulletin 103(2):433-437.
Hoenig, J. M., and D. A. Hewitt. 2005. What can we learn about mortality from sex ratio data? A look at lumpfish in Newfoundland. Transactions of the American Fisheries Society 134:754-761. [Note the two important errata appended to the file.]
Hewitt, D. A., W. E. Pine, III, and A. V. Zale, editors. 2006. The AFS Guide to Fisheries Employment, 2nd Edition. American Fisheries Society, Bethesda, Maryland. (Available through the AFS online bookstore.)
Hewitt, D.A., D.M. Lambert, J.M. Hoenig, R.N. Lipcius, D.B. Bunnell, and T.J. Miller. 2007. Direct and Indirect Estimates of Natural Mortality for Chesapeake Bay Blue Crab. Transactions of the American Fisheries Society, 136(4): 1030-1040.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
Filter Total Items: 29
Avian predation on juvenile and adult Lost River and Shortnose Suckers: An updated multi-predator species evaluation
Previous research suggests that predation by piscivorous colonial waterbirds may negatively influence the survival of Lost River Suckers (LRS) Deltistes luxatus and Shortnose Suckers (SNS) Chasmistes brevirostris in the Upper Klamath Basin (UKB), USA. However, estimates of predation from past studies, which were based on suckers with PIT tags, represent minimum estimates of sucker...
Authors
Allen Evans, Quinn Payton, Nathan V Banet, Bradley M. Cramer, Caylen Kelsey, David A. Hewitt
Distribution of bull trout (Salvelinus confluentus) in conjunction with habitat and trout assemblages in creeks within the Klamath Basin, Oregon 2010–16
Bull trout (Salvelinus confluentus) in the Klamath Basin are on the southernmost border of the range of the species, where threats are most severe and where bull trout are most imperiled. In their recovery plan the U.S. Fish and Wildlife Service (2015, https://ecos.fws.gov/ecp/report/species-with-recovery-plans) suggested that Klamath Basin bull trout are at increased risk of extirpation...
Authors
Barbara A. Martin, Nolan Banish, David A. Hewitt, Brian S. Hayes, Amari Dolan-Caret, Alta C. Harris, Caylen Kelsey
Avian predation of juvenile Lost River and Shortnose Suckers in Upper Klamath Lake: An assessment of Sucker assisted rearing program releases during 2018–2020
To bolster recruitment in Endangered Species Act (ESA) listed Lost River Suckers (Deltistes luxatus) and Shortnose Suckers (Chasmistes brevirostris) in the Upper Klamath Basin (UKB), the U.S. Fish and Wildlife Service (USFWS) and its partners have implemented the Sucker Assisted Rearing Program (SARP). As part of this program, juvenile suckers were reared in captivity, implanted with...
Authors
Allen Evans, Quinn Payton, Nathan V Banet, Bradley M. Cramer, Caylen Kelsey, David A. Hewitt
Spatial and temporal distribution of radio-tagged Lost River (Deltistes luxatus) and shortnose (Chasmistes brevirostris) suckers in Clear Lake Reservoir and associated spawning tributaries, Northern California, 2015–17
Executive SummaryData from a multi-year radio telemetry study were used to assess seasonal distribution patterns for two long-lived, federally endangered catostomids across substantially different water conditions in Clear Lake Reservoir, northern California. Lost River (Deltistes luxatus) and shortnose (Chasmistes brevirostris) suckers, two species endemic to the Klamath Basin, were...
Authors
Nathan Banet, David A. Hewitt, Amari Dolan-Caret, Alta C. Harris
Dynamics of endangered sucker populations in Clear Lake Reservoir, California
Executive SummaryIn collaboration with the Bureau of Reclamation, the U.S. Geological Survey began a consistent monitoring program for endangered Lost River suckers (Deltistes luxatus) and shortnose suckers (Chasmistes brevirostris) in Clear Lake Reservoir, California, in fall 2004. The program was intended to improve understanding of the Clear Lake Reservoir populations because they are...
Authors
David A. Hewitt, Brian S. Hayes, Alta C. Harris, Eric C. Janney, Caylen M. Kelsey, Russell W. Perry, Summer M. Burdick
Effects of harmful algal blooms and associated water-quality on endangered Lost River and shortnose suckers
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...
Authors
Summer M. Burdick, David A. Hewitt, Barbara A. Martin, Liam N. Schenk, Stewart A. Rounds
Characterization of the genetic structure of four sucker species in the Klamath River. Final Report
Four species of suckers (family Catostomidae) inhabit the Klamath River Basin of Oregon and California: Lost River suckers (LRS; Deltistes luxatus), shortnose suckers (SNS; Chasmistes brevirostris), Klamath largescale suckers (KLS; Catostomus snyderi), and Klamath smallscale suckers (KSS; Catostomus rimiculus). All but Klamath smallscale suckers are endemic and restricted to the Klamath...
Authors
Matt Smith, Jennifer Von Bargen, Christian A. Smith, Michael A. Miller, Josh Rasmussen, David A. Hewitt
Monitoring of endangered Klamath Basin suckers translocated from Lake Ewauna to Upper Klamath Lake, Oregon, 2014−2017
Data from a 4-year capture and transport program were used to assess translocation as a management strategy for two long-lived, federally endangered catostomids in the Upper Klamath Basin, Oregon. Lost River (Deltistes luxatus) and shortnose (Chasmistes brevirostris) suckers, two species endemic to the Klamath Basin, were translocated from Lake Ewauna to Upper Klamath Lake in each of 4...
Authors
Nathan V. Banet, David A. Hewitt
Status and trends of adult Lost River (Deltistes luxatus) and shortnose (Chasmistes brevirostris) sucker populations in Upper Klamath Lake, Oregon, 2017
Executive SummaryData from a long-term capture-recapture program were used to assess the status and dynamics of populations of two long-lived, federally endangered catostomids in Upper Klamath Lake, Oregon. Lost River suckers (LRS; Deltistes luxatus) and shortnose suckers (SNS; Chasmistes brevirostris) have been captured and tagged with passive integrated transponder (PIT) tags during...
Authors
David A. Hewitt, Eric C. Janney, Brian S. Hayes, Alta C. Harris
Status and trends of adult Lost River (Deltistes luxatus) and shortnose (Chasmistes brevirostris) sucker populations in Upper Klamath Lake, Oregon, 2015
Executive SummaryData from a long-term capture-recapture program were used to assess the status and dynamics of populations of two long-lived, federally endangered catostomids in Upper Klamath Lake, Oregon. Lost River suckers (LRS; Deltistes luxatus) and shortnose suckers (SNS; Chasmistes brevirostris) have been captured and tagged with passive integrated transponder (PIT) tags during...
Authors
David A. Hewitt, Eric C. Janney, Brian S. Hayes, Alta C. Harris
Colonial waterbird predation on Lost River and Shortnose suckers in the Upper Klamath Basin
We evaluated predation on Lost River Suckers Deltistes luxatus and Shortnose Suckers Chasmistes brevirostris by American white pelicans Pelecanus erythrorhynchos and double-crested cormorants Phalacrocorax auritus nesting at mixed-species colonies in the Upper Klamath Basin of Oregon and California during 2009–2014. Predation was evaluated by recovering (detecting) PIT tags from tagged...
Authors
Allen F. Evans, David A. Hewitt, Quinn Payton, Bradley M. Cramer, Ken Collis, Daniel D. Roby
The logic of comparative life history studies for estimating key parameters, with a focus on natural mortality rate
There are a number of key parameters in population dynamics that are difficult to estimate, such as natural mortality rate, intrinsic rate of population growth, and stock-recruitment relationships. Often, these parameters of a stock are, or can be, estimated indirectly on the basis of comparative life history studies. That is, the relationship between a difficult to estimate parameter...
Authors
John M Hoenig, Amy Y.-H. Then, Elizabeth A. Babcock, Norman G. Hall, David A. Hewitt, Sybrand A. Hesp
Non-USGS Publications**
Hewitt, D. A., and J. M. Hoenig. 2005. Comparison of two approaches for estimating natural mortality based on longevity. Fishery Bulletin 103(2):433-437.
Hoenig, J. M., and D. A. Hewitt. 2005. What can we learn about mortality from sex ratio data? A look at lumpfish in Newfoundland. Transactions of the American Fisheries Society 134:754-761. [Note the two important errata appended to the file.]
Hewitt, D. A., W. E. Pine, III, and A. V. Zale, editors. 2006. The AFS Guide to Fisheries Employment, 2nd Edition. American Fisheries Society, Bethesda, Maryland. (Available through the AFS online bookstore.)
Hewitt, D.A., D.M. Lambert, J.M. Hoenig, R.N. Lipcius, D.B. Bunnell, and T.J. Miller. 2007. Direct and Indirect Estimates of Natural Mortality for Chesapeake Bay Blue Crab. Transactions of the American Fisheries Society, 136(4): 1030-1040.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.