David Ward (Former Employee)
Science and Products
Eelgrass
Eelgrass is the predominant aquatic plant within embayments of southwestern Alaska and provides an important habitat for birds, fish, and invertebrates. The USGS has conducted extensive research on the status, trends, and use of eelgrass by migratory birds in southwestern Alaska primarily at the Izembek National Wildlife Refuge.
Effects of water clarity on humpback chub
Introduced rainbow trout and brown trout are considered a threat to the endangered humpback chub in the Colorado River in Grand Canyon. These introduced species eat native fish, but impacts are difficult to assess because predation vulnerability depends on the physical conditions under which predation takes place. We studied how predation vulnerability of juvenile humpback chub changes in response...
Laboratory Predation Data (various nonnative warm-water sport fishes), Arizona
These data were compiled to evaluate the potential impact various environmental conditions may have on native fish populaitons through predation. Introduced warm-water sport fishes present a high predation risk for juvenile native fishes, but observations of juvenile native fish surviving and recruiting in some rare cases led us to question what environmental conditions might be...
Hatchery Trout Predation Data, Arizona
These data were compiled to evaluate the potential adverse impacts that stocked trout may have on native fish populaitons through predation. Hatchery-reared rainbow and brown trout are typically fed exclusively on commercially prepared pelleted feeds and have no experience catching or consuming life fish at the time of stocking and yet stocked fish are percieved to present a high...
Bioelectrical impedance analysis for an endangered desert fishData
These data were used to examine the effectiveness of a non-lethal tool (Bioelectrical Impedance Analysis, "BIA") to estimate the physiological condition of endangered and threatened fishes in the Colorado River Basin. We conducted laboratory trials using hatchery-raised Humpback Chub and Bonytail and wild-captured Roundtail Chub, where fish were subjected to different feeding trials to...
Filter Total Items: 32
U.S. Geological Survey Grand Canyon Monitoring and Research Center: Proceedings of the fiscal year 2023 annual reporting meeting to the Glen Canyon Dam Adaptive Management Program
This proceedings is prepared for the USBR and Glen Canyon Dam Adaptive Management Program (GCDAMP) to account for work conducted and products delivered in FY 2023 by SBSC's Grand Canyon Monitoring and Research Center (GCMRC) and to inform the Technical Work Group of science conducted by GCMRC and its cooperators in support of the GCDAMP. It includes a summary of accomplishments...
Authors
Andrew Alan Schultz, Gregory Mark Anderson, David Topping, Ronald E. Griffiths, David Dean, Paul E. Grams, Keith A. Kohl, Gerard Lewis Salter, Matthew A. Kaplinski, Katherine Anne Chapman, Erich R. Mueller, Emily C. Palmquist, Bradley J. Butterfield, Joel B. Sankey, Bridget Deemer, Charles B. Yackulic, Lindsay Erika Hansen, Drew Elliot Eppehimer, Theodore A. Kennedy, Anya N. Metcalfe, Jeffrey D. Muehlbauer, Morgan Ford, Michael J. Dodrill, Maria C. Dzul, Pilar Rinker, Michael J. Pillow, David L. Ward, Josh Korman, Molly A.H. Webb, James A. Crossman, Eric J Frye, David L. Rogowski, Kimberley Dibble, Lucas S. Bair, Joshua Abbott, Tom Gushue, Erica Paige Byerley, Joseph E Thomas, Thomas A. Sabol, Bryce Anthony Mihalevich
Evaluating conservation units using network analysis: A sea duck case study
Conserving migratory wildlife requires understanding how groups of individuals interact across seasons and landscapes. Telemetry reveals individual movements at large spatiotemporal scales; however, using movement data to define conservation units requires scaling up from individual movements to species- and community-level patterns. We developed a framework to define flyways and...
Authors
Juliet S. Lamb, Clara Cooper-Mullin, Scott G. Gilliland, Alicia Berlin, Timothy D. Bowman, W. Sean Boyd, Susan E.W. De La Cruz, Daniel Esler, Joseph R. Evenson, Paul L. Flint, Christine Lepage, Dustin E. Meattey, Jason E. Osenkowski, Peter WC Patton, Matthew Perry, Daniel K. Rosenberg, Jean-Pierre L. Savard, Lucas J Savoy, Jason L. Schamber, David L. Ward, John Y. Takekawa, Scott R. McWilliams
Proceedings of the Fiscal Year 2022 Annual Reporting Meeting to the Glen Canyon Dam Adaptive Management Program
(Hartwell) This report is prepared primarily to account for work conducted and products delivered in FY 2022 by GCMRC and to inform the Technical Work Group of science conducted by GCMRC and its cooperators in support of the Glen Canyon Dam Adaptive Management Program (GCDAMP). It includes a summary of accomplishments, modifications to work plans, results, and recommendations related to...
Authors
David Topping, Paul E. Grams, Emily C. Palmquist, Joel B. Sankey, Helen Fairley, Bridget Deemer, Charles B. Yackulic, Theodore A. Kennedy, Anya N. Metcalfe, Maria C. Dzul, David Ward, Mariah Aurelia Giardina, Lucas S. Bair, Tom Gushue, Caitlin M. Andrews, Ronald E. Griffiths, David Dean, Keith A. Kohl, Michael J. Moran, Nicholas Voichick, Thomas A. Sabol, Laura A. Tennant, Kimberley Dibble, Michael Runge
Comparison of electrofishing and PIT antennas for detection of hatchery-reared Roundtail Chub (Gila robusta) stocked into a desert stream
Stocking of rare native fishes for conservation purposes is a common practice in the southwestern United States. Monitoring typically occurs after hatchery-reared fish are released to assess post-stocking movement and survival. We conducted a two-year study, in which tow-barge electrofishing and portable, flat-bed passive integrated transponder (PIT) antennas were used to monitor PIT...
Authors
Laura A. Tennant, David Ward, Alice C. Gibb
What's in the hump of the humpback chub?
The function of the nuchal hump on adult humpback chub (Gila cypha) has been the subject of longtime conjecture. Hypotheses about the purpose of the hump range from it being a feature that confers hydrodynamic advantages in swift water to speculation about how the hump may have reduced predation vulnerability to Colorado pikeminnows (Ptychocheilus lucius). We used comparative histology...
Authors
David Ward, Michael P. Ward
Viability of Razorback-Flannelmouth Sucker hybrids
Razorback sucker (Xyrauchen texanus) and flannelmouth sucker (Catostomus latipinnis) live in sympatry in the Colorado River basin. Although morphological intermediates have been described since 1889, hybrids were seemingly rare. Rarity of hybrids was likely attributed to razorback suckers' ability to find conspecific mates throughout the basin. Dams have segmented the Colorado River...
Authors
Pilar N. Wolters, David L. Rogowski, David Ward, Alice C. Gibb
An evaluation of sedatives for use in transport of juvenile endangered fishes in plastic bags
Trucks and aircraft typically transport rare or endangered fishes in large unsealed tanks containing large volumes of water (typically hundreds of liters) during conservation efforts. Ornamental fishes, however, are commonly sent by mail in small sealed plastic bags filled with oxygen, minimal water, and a small amount of sedative to reduce weight and overall shipping costs. Our goal was...
Authors
Laura A. Tennant, Benjamin Vaage, David Ward
Geographic variation in the intensity of warming and phenological mismatch between Arctic shorebirds and invertebrates
Responses to climate change can vary across functional groups and trophic levels, leading to a temporal decoupling of trophic interactions or ‘phenological mismatches.’ Despite a growing number of single-species studies that identified phenological mismatches as a nearly universal consequence of climate change, we have a limited understanding of the spatial variation in the intensity of...
Authors
Enubi Kwon, Emily L. Weiser, Richard Lanctot, Stephen C. Brown, H. River Gates, H. Grant Gilchrist, Steve J. Kendall, David B. Lank, Joseph R. Liebezeit, Laura McKinnon, Erica Nol, David C. Payer, Jennie Rausch, Sarah T. Saalfeld, Daniel J. Rinella, Nathan R. Senner, David Ward, Paul A Smith, Robert C. Wissman, Brett K. Sandercock
What environmental conditions reduce predation vulnerability for juvenile Colorado River native fishes?
The incompatibility of native Colorado River fishes and nonnative warm-water sport fishes is well documented with predation by nonnative species causing rapid declines and even extirpation of native species in most locations. In a few rare instances native fishes are able to survive and recruit despite the presence of nonnative warm water predators, indicating that specific environmental...
Authors
David Ward, Benjamin Vaage
Change in dominance determines herbivore effects on plant biodiversity
Herbivores alter plant biodiversity (species richness) in many of the world’s ecosystems, but the magnitude and the direction of herbivore effects on biodiversity vary widely within and among ecosystems. One current theory predicts that herbivores enhance plant biodiversity at high productivity but have the opposite effect at low productivity. Yet, empirical support for the importance of...
Authors
Sally E. Koerner, Melinda D. Smith, Deron E. Burkepile, P. Niall Hanan, Meghan L. Avolio, Scott M. Collins, Alan K. Knapp, Nathan P. Lemoine, Elisabeth J. Forrestel, Stephanie Eby, Dave I. Thompson, Gerardo A. Aguado-Santacruz, John P. Anderson, T. W. Anderson, Ayana Angassa, Sumanta Bagchi, Elisabeth S. Bakker, Gary Bastin, Lauren E. Baur, Karen H. Beard, Erik A. Beever, Patrick J. Bohlen, Elizabeth H. Boughton, Don Canestro, Ariela Cesa, Enrique Chaneton, Jimin Cheng, Carla M. D'Antonio, Claire Deleglise, Fadiala Dembélé, Josh Dorrough, David J. Eldridge, Barbara Fernandez-Going, Silvia Fernández-Lugo, Lauchlan H. Fraser, Bill Freedman, Gonzalo García-Salgado, Jacob R. Goheen, Liang Guo, Sean Husheer, Moussa Karembé, Johannes MH Knops, Tineke Kraaij, Andrew Kulmatiski, Minna-Maarit Kytöviita, Felipe Lezama, Gregory Loucougaray, Alejandro Loydi, Daniel G. Milchunas, Suzanne J. Milton, John W. Morgan, Claire Moxham, Kyle C. Nehring, Han Olff, Todd M. Palmer, Salvador Rebollo, Corinna Riginos, Anita C. Risch, Marta Rueda, Mahesh Sankaran, Takehiro Sasaki, Kathryn A. Schoenecker, Nick L. Schultz, Martin Schütz, Angelika Schwabe, Frances Siebert, Christian Smit, Karen A. Stahlheber, Christian Storm, Dustin J. Strong, Jishuai Su, Yadugiri V. Tiruvaimozhi, Claudia Tyler, James Val, Martijn L. Vandegehuchte, Kari E. Veblen, Lance T Vermeire, David L. Ward, Jianshuang Wu, Truman P. Young, Qiang Yu, Tamara J. Zelikova
Are hatchery-reared Rainbow Trout and Brown Trout effective predators on juvenile native fish?
Hatchery‐reared Rainbow Trout Oncorhynchus mykiss and Brown Trout Salmo trutta are typically fed exclusively on commercially prepared pelleted feeds and have no experience catching or consuming live fish at the time of stocking. Despite this lack of predation experience, it is commonly assumed that stocked Rainbow Trout and Brown Trout will adversely impact native fish populations by...
Authors
David Ward, Rylan Morton-Starner, Benjamin Vaage
Effectiveness of ultrasonic imaging for evaluating presence and maturity of eggs in fishes in remote field locations
Ultrasonic imaging is an effective, nonlethal method used to determine sex and maturity in a variety of fishes. However, many previous studies of this technique have been performed in laboratory environments. Using Common Carp Cyprinus carpio, we developed a standardized method for ultrasonically scanning cyprinids, and we accurately sexed 78% (N = 58) of those individuals. We then...
Authors
Morgan E. Brizendine, David Ward, Scott A. Bonar
Colorado River Basin Projects
The Colorado River Basin Actionable and Strategic Integrated Science and Technology Team has created an interactive map of USGS projects to highlight the integrated science currently conducted within the Colorado River Basin. These projects are not all inclusive of the work conducted by the USGS within the CRB, but highlight the broad range of integrated science currently conducted.
Science and Products
Eelgrass
Eelgrass is the predominant aquatic plant within embayments of southwestern Alaska and provides an important habitat for birds, fish, and invertebrates. The USGS has conducted extensive research on the status, trends, and use of eelgrass by migratory birds in southwestern Alaska primarily at the Izembek National Wildlife Refuge.
Effects of water clarity on humpback chub
Introduced rainbow trout and brown trout are considered a threat to the endangered humpback chub in the Colorado River in Grand Canyon. These introduced species eat native fish, but impacts are difficult to assess because predation vulnerability depends on the physical conditions under which predation takes place. We studied how predation vulnerability of juvenile humpback chub changes in response...
Laboratory Predation Data (various nonnative warm-water sport fishes), Arizona
These data were compiled to evaluate the potential impact various environmental conditions may have on native fish populaitons through predation. Introduced warm-water sport fishes present a high predation risk for juvenile native fishes, but observations of juvenile native fish surviving and recruiting in some rare cases led us to question what environmental conditions might be...
Hatchery Trout Predation Data, Arizona
These data were compiled to evaluate the potential adverse impacts that stocked trout may have on native fish populaitons through predation. Hatchery-reared rainbow and brown trout are typically fed exclusively on commercially prepared pelleted feeds and have no experience catching or consuming life fish at the time of stocking and yet stocked fish are percieved to present a high...
Bioelectrical impedance analysis for an endangered desert fishData
These data were used to examine the effectiveness of a non-lethal tool (Bioelectrical Impedance Analysis, "BIA") to estimate the physiological condition of endangered and threatened fishes in the Colorado River Basin. We conducted laboratory trials using hatchery-raised Humpback Chub and Bonytail and wild-captured Roundtail Chub, where fish were subjected to different feeding trials to...
Filter Total Items: 32
U.S. Geological Survey Grand Canyon Monitoring and Research Center: Proceedings of the fiscal year 2023 annual reporting meeting to the Glen Canyon Dam Adaptive Management Program
This proceedings is prepared for the USBR and Glen Canyon Dam Adaptive Management Program (GCDAMP) to account for work conducted and products delivered in FY 2023 by SBSC's Grand Canyon Monitoring and Research Center (GCMRC) and to inform the Technical Work Group of science conducted by GCMRC and its cooperators in support of the GCDAMP. It includes a summary of accomplishments...
Authors
Andrew Alan Schultz, Gregory Mark Anderson, David Topping, Ronald E. Griffiths, David Dean, Paul E. Grams, Keith A. Kohl, Gerard Lewis Salter, Matthew A. Kaplinski, Katherine Anne Chapman, Erich R. Mueller, Emily C. Palmquist, Bradley J. Butterfield, Joel B. Sankey, Bridget Deemer, Charles B. Yackulic, Lindsay Erika Hansen, Drew Elliot Eppehimer, Theodore A. Kennedy, Anya N. Metcalfe, Jeffrey D. Muehlbauer, Morgan Ford, Michael J. Dodrill, Maria C. Dzul, Pilar Rinker, Michael J. Pillow, David L. Ward, Josh Korman, Molly A.H. Webb, James A. Crossman, Eric J Frye, David L. Rogowski, Kimberley Dibble, Lucas S. Bair, Joshua Abbott, Tom Gushue, Erica Paige Byerley, Joseph E Thomas, Thomas A. Sabol, Bryce Anthony Mihalevich
Evaluating conservation units using network analysis: A sea duck case study
Conserving migratory wildlife requires understanding how groups of individuals interact across seasons and landscapes. Telemetry reveals individual movements at large spatiotemporal scales; however, using movement data to define conservation units requires scaling up from individual movements to species- and community-level patterns. We developed a framework to define flyways and...
Authors
Juliet S. Lamb, Clara Cooper-Mullin, Scott G. Gilliland, Alicia Berlin, Timothy D. Bowman, W. Sean Boyd, Susan E.W. De La Cruz, Daniel Esler, Joseph R. Evenson, Paul L. Flint, Christine Lepage, Dustin E. Meattey, Jason E. Osenkowski, Peter WC Patton, Matthew Perry, Daniel K. Rosenberg, Jean-Pierre L. Savard, Lucas J Savoy, Jason L. Schamber, David L. Ward, John Y. Takekawa, Scott R. McWilliams
Proceedings of the Fiscal Year 2022 Annual Reporting Meeting to the Glen Canyon Dam Adaptive Management Program
(Hartwell) This report is prepared primarily to account for work conducted and products delivered in FY 2022 by GCMRC and to inform the Technical Work Group of science conducted by GCMRC and its cooperators in support of the Glen Canyon Dam Adaptive Management Program (GCDAMP). It includes a summary of accomplishments, modifications to work plans, results, and recommendations related to...
Authors
David Topping, Paul E. Grams, Emily C. Palmquist, Joel B. Sankey, Helen Fairley, Bridget Deemer, Charles B. Yackulic, Theodore A. Kennedy, Anya N. Metcalfe, Maria C. Dzul, David Ward, Mariah Aurelia Giardina, Lucas S. Bair, Tom Gushue, Caitlin M. Andrews, Ronald E. Griffiths, David Dean, Keith A. Kohl, Michael J. Moran, Nicholas Voichick, Thomas A. Sabol, Laura A. Tennant, Kimberley Dibble, Michael Runge
Comparison of electrofishing and PIT antennas for detection of hatchery-reared Roundtail Chub (Gila robusta) stocked into a desert stream
Stocking of rare native fishes for conservation purposes is a common practice in the southwestern United States. Monitoring typically occurs after hatchery-reared fish are released to assess post-stocking movement and survival. We conducted a two-year study, in which tow-barge electrofishing and portable, flat-bed passive integrated transponder (PIT) antennas were used to monitor PIT...
Authors
Laura A. Tennant, David Ward, Alice C. Gibb
What's in the hump of the humpback chub?
The function of the nuchal hump on adult humpback chub (Gila cypha) has been the subject of longtime conjecture. Hypotheses about the purpose of the hump range from it being a feature that confers hydrodynamic advantages in swift water to speculation about how the hump may have reduced predation vulnerability to Colorado pikeminnows (Ptychocheilus lucius). We used comparative histology...
Authors
David Ward, Michael P. Ward
Viability of Razorback-Flannelmouth Sucker hybrids
Razorback sucker (Xyrauchen texanus) and flannelmouth sucker (Catostomus latipinnis) live in sympatry in the Colorado River basin. Although morphological intermediates have been described since 1889, hybrids were seemingly rare. Rarity of hybrids was likely attributed to razorback suckers' ability to find conspecific mates throughout the basin. Dams have segmented the Colorado River...
Authors
Pilar N. Wolters, David L. Rogowski, David Ward, Alice C. Gibb
An evaluation of sedatives for use in transport of juvenile endangered fishes in plastic bags
Trucks and aircraft typically transport rare or endangered fishes in large unsealed tanks containing large volumes of water (typically hundreds of liters) during conservation efforts. Ornamental fishes, however, are commonly sent by mail in small sealed plastic bags filled with oxygen, minimal water, and a small amount of sedative to reduce weight and overall shipping costs. Our goal was...
Authors
Laura A. Tennant, Benjamin Vaage, David Ward
Geographic variation in the intensity of warming and phenological mismatch between Arctic shorebirds and invertebrates
Responses to climate change can vary across functional groups and trophic levels, leading to a temporal decoupling of trophic interactions or ‘phenological mismatches.’ Despite a growing number of single-species studies that identified phenological mismatches as a nearly universal consequence of climate change, we have a limited understanding of the spatial variation in the intensity of...
Authors
Enubi Kwon, Emily L. Weiser, Richard Lanctot, Stephen C. Brown, H. River Gates, H. Grant Gilchrist, Steve J. Kendall, David B. Lank, Joseph R. Liebezeit, Laura McKinnon, Erica Nol, David C. Payer, Jennie Rausch, Sarah T. Saalfeld, Daniel J. Rinella, Nathan R. Senner, David Ward, Paul A Smith, Robert C. Wissman, Brett K. Sandercock
What environmental conditions reduce predation vulnerability for juvenile Colorado River native fishes?
The incompatibility of native Colorado River fishes and nonnative warm-water sport fishes is well documented with predation by nonnative species causing rapid declines and even extirpation of native species in most locations. In a few rare instances native fishes are able to survive and recruit despite the presence of nonnative warm water predators, indicating that specific environmental...
Authors
David Ward, Benjamin Vaage
Change in dominance determines herbivore effects on plant biodiversity
Herbivores alter plant biodiversity (species richness) in many of the world’s ecosystems, but the magnitude and the direction of herbivore effects on biodiversity vary widely within and among ecosystems. One current theory predicts that herbivores enhance plant biodiversity at high productivity but have the opposite effect at low productivity. Yet, empirical support for the importance of...
Authors
Sally E. Koerner, Melinda D. Smith, Deron E. Burkepile, P. Niall Hanan, Meghan L. Avolio, Scott M. Collins, Alan K. Knapp, Nathan P. Lemoine, Elisabeth J. Forrestel, Stephanie Eby, Dave I. Thompson, Gerardo A. Aguado-Santacruz, John P. Anderson, T. W. Anderson, Ayana Angassa, Sumanta Bagchi, Elisabeth S. Bakker, Gary Bastin, Lauren E. Baur, Karen H. Beard, Erik A. Beever, Patrick J. Bohlen, Elizabeth H. Boughton, Don Canestro, Ariela Cesa, Enrique Chaneton, Jimin Cheng, Carla M. D'Antonio, Claire Deleglise, Fadiala Dembélé, Josh Dorrough, David J. Eldridge, Barbara Fernandez-Going, Silvia Fernández-Lugo, Lauchlan H. Fraser, Bill Freedman, Gonzalo García-Salgado, Jacob R. Goheen, Liang Guo, Sean Husheer, Moussa Karembé, Johannes MH Knops, Tineke Kraaij, Andrew Kulmatiski, Minna-Maarit Kytöviita, Felipe Lezama, Gregory Loucougaray, Alejandro Loydi, Daniel G. Milchunas, Suzanne J. Milton, John W. Morgan, Claire Moxham, Kyle C. Nehring, Han Olff, Todd M. Palmer, Salvador Rebollo, Corinna Riginos, Anita C. Risch, Marta Rueda, Mahesh Sankaran, Takehiro Sasaki, Kathryn A. Schoenecker, Nick L. Schultz, Martin Schütz, Angelika Schwabe, Frances Siebert, Christian Smit, Karen A. Stahlheber, Christian Storm, Dustin J. Strong, Jishuai Su, Yadugiri V. Tiruvaimozhi, Claudia Tyler, James Val, Martijn L. Vandegehuchte, Kari E. Veblen, Lance T Vermeire, David L. Ward, Jianshuang Wu, Truman P. Young, Qiang Yu, Tamara J. Zelikova
Are hatchery-reared Rainbow Trout and Brown Trout effective predators on juvenile native fish?
Hatchery‐reared Rainbow Trout Oncorhynchus mykiss and Brown Trout Salmo trutta are typically fed exclusively on commercially prepared pelleted feeds and have no experience catching or consuming live fish at the time of stocking. Despite this lack of predation experience, it is commonly assumed that stocked Rainbow Trout and Brown Trout will adversely impact native fish populations by...
Authors
David Ward, Rylan Morton-Starner, Benjamin Vaage
Effectiveness of ultrasonic imaging for evaluating presence and maturity of eggs in fishes in remote field locations
Ultrasonic imaging is an effective, nonlethal method used to determine sex and maturity in a variety of fishes. However, many previous studies of this technique have been performed in laboratory environments. Using Common Carp Cyprinus carpio, we developed a standardized method for ultrasonically scanning cyprinids, and we accurately sexed 78% (N = 58) of those individuals. We then...
Authors
Morgan E. Brizendine, David Ward, Scott A. Bonar
Colorado River Basin Projects
The Colorado River Basin Actionable and Strategic Integrated Science and Technology Team has created an interactive map of USGS projects to highlight the integrated science currently conducted within the Colorado River Basin. These projects are not all inclusive of the work conducted by the USGS within the CRB, but highlight the broad range of integrated science currently conducted.