Kaitlyn Gahl

After graduating from Montana State University, Kaitlyn worked seasonal fisheries jobs across the western U.S. She hopped state to state working with montane trout, prairie minnows, pacific salmon, and desert fishes. These native species inspired her, and in 2020 she began her masters in the Bonar Lab. Her research focuses on habitat utilization of fishes in the Lower Verde River subbasin. Year round you can find her in the lush desert canyons of northern Arizona snorkeling and tracking fish with radio telemetry. This research is vital in securing water rights for wilderness tributaries of the Verde River, ensuring continued habitat for native desert fishes.

Joshua Grant

Earned a B.S. in Wildlife Science from New Mexico State University in 2016. After graduating, Josh got a job with U.S. Fish and Wildlife Service mainly working with the endangered Rio Grande Silvery Minnow. Josh then accepted a graduate position for fall 2019 to work towards his masters degree in fisheries management. His project included working with the Arizona Game and Fish Department to help standardize gill net and boat electrofishing surveys to align with those of the American Fisheries Society. Upon graduating in 2022, he is now a warm water sportfish biologist with New Mexico Department of Game and Fish.

Matthew Recsetar

Matthew Recsetar received a BS in Neurobiology at William and Mary College in Williamsburg, Viginia. He then decided a fisheries career was more to his liking, and joined the University of Arizona to work on an MS in fisheries. Matt's work was focused on understanding the temperature tolerance of Apache trout, Arizona's state fish. Apache trout are one of the most southern trout species, and biologists need to understand their thermal requirements to help protect the species and manage streams. Matt worked with state and federal fisheries biologists to develop thermal tolerance criteria for the Apache trout, and tested management techniques for other stream organisms such as crayfish. He also learned fish rearing techniques at the University of Arizona and had a strong interest in aquaculture. Following graduation, he took a position as an Aquaculture Extension Specialist at the Univeristy of Arkansas Pine Bluff.

Christina Perez

Christina Perez received her B.S. in Forest Wildlife from Western New Mexico University in the spring of 2011. For her senior practicum in 2010 she worked with a fisheries biologist from the Forest Service in the Gila National Forest doing non-native fish removal in the Gila River. This was the point where her career interests shifted to the field of fisheries. Since this experience she has worked in Alaska on the Kenai peninsula locating suitable habitats for juvenile Chinook and Coho salmon. Also, she have worked as a seasonal fisheries technician with Colorado Parks and Wildlife in Meeker, Colorado and in Vernal, Utah, for the Utah Division of Natural Resources. In both of these positions, she gained valuable experience as an integral part of the Upper Colorado River Endangered Fish Recovery Program doing non-native fish removal in the Yampa River and Green River. Through her fisheries positions she also gained experience with multiple sampling methods in numerous streams, large rivers, floodplains, lakes, and large reservoirs. While working on her MS with AZCFWRU at The University of Arizona, her project entailed working on large reservoirs in Arizona collecting data using AFS standard methods and using of eDNA to detect the presence of species and their relative abundance.

Timofey Specivy

Dr. Timofey Specivy (standing) was a visiting scholar from the Institute of Fisheries of the Ukrainian Academy of Agrarian Sciences. He was a former Fisheries Enforcement Officer for the Ukrainian fisheries management agency before he received his Ph.D. in fisheries biology in Kiev. He worked with Dr. Kuzmenko on mechanical removal methods for invasive populations of Northern pike. Northern pike can decimate populations of other fishes in lakes if illegally introduced, and management strategies for agencies are important. Timofey lended his Eastern European experience to develop mechanical removal methods for invasive populations of Northern Pike (Esox lucius) in Arizona reservoirs.

Norman Mercado-Silva

Dr. Norman Mercado-Silva received a BS in Biology from the Universidad Nacional Autonoma de Mexico in Mexico City [National University in Mexico (UNAM)], and an MS in Conservation Biology and Sustainable Development and a Ph.D in Zoology and Limnology from the University of Wisconsin - Madison. Norman is interested in many different aspects of environmental science, especially in the conservation and management of freshwater ecosystems and fish biology, ecology, and conservation. Specifically, his research has involved the ecology and distribution of invasive species, stream biomonitoring, and stable isotope-based studies of trophic relationships in freshwater ecosystems. He is very interested in how aquatic ecosystems respond to a variety of anthropogenic stressors, in the development of tools that can help identify these responses, and in the mitigation of these stressors. More recently he has been involved in the estimation of habitat suitability criteria for fish in desert streams and the implementation and development of standard methods for sampling freshwater fish. More information at: https://sites.google.com/site/normanmercadosilva/

Olin Feuerbacher

Olin Feuerbacher recieved a BS in Ecology and Evolutionary Biology from the University of Arizona, was employed as staff, and is working on an MS at the University of Arizona. Olin brought great expertise in fish rearing and propagation to his work at the University of Arizona, where he served as a Fisheries Laboratory Manager, and an endangered fish propagation biologist. His MS work centers on developing better methods to propagate and rear Devils Hole pupfish and related species, which will be used by the US Fish and Wildlife service in their plans for propagating and managing the fish. Olin is currently employed as a fisheries biologist and propagation specialist at the U.S. Fish and Wildlife Service's Ash Meadows National Wildlife Refuge, Pahrump, Nevada, and is in the final stages of completing his degree.

Joy Price

Joy Price received a Bachelor's degree in Marine Sciences at Coastal Carolina University and then came to the University of Arizona to study factors affecting stream temperatures in waters containing Apache trout. Joy's work discussed how heat enters streams and identified types of riparian plant community, stream flow and groundwater management techniques that could be used to cool streams to make them more suited for the rare trout. Her work was especially relevant, given ongoing stream warming due to climate change and other factors. Joy had to adjust her study because of the huge Wallow wildfire that raged through her study area midway through her degree. She did a fine job adjusting to the changes and graduated spring, 2013

David Rogowski

David Rogowski received his Ph.D. from North Dakota State University and joined the University of Arizona as a post-doctoral researcher. David studied ways to optimize the control of invasive crayfish in Arizona streams and rivers. No native crayfish occur within Arizona; however, the northern crayfish has been introduced in a number of water bodies throughout the state and predates and competes with native animals and destroys aquatic vegetation. David's work allows agency biologists to optimize their control strategies for the crayfish. Following his work at the University of Arizona, David was first employed as a professor at Texas Tech University and currently leads Colorado River fisheries studies in the Grand Canyon studies for the Arizona Game and Fish Department.

Thomas Archdeacon

Thomas Archdeacon leads the Rio Grande Silvery Minnow salvage and augmentation program to help recover Rio Grande Silvery Minnow. Additionally, serves as an associate editor for the North American Journal of Fisheries Management.

Cori Carveth

Cori Carveth received her BS degree from Trent University in Peterborough, Ontario, Canada. Upon completion, she worked as a fisheries biologist for the Peterborough District of the Ontario Ministry of Natural Resources for two years before beginning her masters research at the University of Arizona. The topic of her thesis involved a comparison of the upper lethal tolerances of nineteen native and nonnative fish species in Arizona. She also worked cooperatively with Ann Widmer to test the thermal tolerances of the threatened species spikedace, Meda fulgida and loachminnow, Tioroga cobitis, under static and fluctuating conditions. The latter experiment involved the construction of a large recirculating computerized laboratory facility. This information was important for management agencies to understand the thermal tolerances of various fishes in the southwestern United States, and manage water bodies accordingly. Cori successfully completed her thesis in the spring of 2005 and an advanced in a series of postions from the Utah Division of Wildlife Resources; the Arizona Game and Fish Department; Ontario Ministry of Natural Resources. She is now a Biologist and Project Manager at Golder Associates Ltd, Ontario, Canada.

Chuck Schade

Chuck Schade received a BS degree at the University of Montana. He worked for a period with the Utah Division of Wildlife before coming to the University of Arizona to get his MS degree. Chuck worked with the U.S. Environmental Protection Agency on a project that sampled the fish, invertebrates and water quality of streams throughout the American West. His MS concentrated on patterns in the distribution and abundance of introduced fishes in the West. Chuck was responsible for the Arizona portion of sampling for this national project, but examined data throughout the West for his MS thesis. He found that over 50% of streams in the West contain nonnative fish. He graduated in December 2004, and was employed by Harris Consulting and the U.S. Fish and Wildlife Service before obtaining his current job as a biologist and project manager at BioResource Consultants Inc. in Los Angeles, California.

Alexander Didenko

Alexander Didenko received an undergraduate degree at the University of Moscow in Ichthyology. He worked several years with Marine fisheries agencies in the former Soviet Union studying the biology of arctic fishes and reservoir species, and later received a MS degree in France. Alexander changed tracks considerably when he came to study desert fishes. He developed relative weight equations to help sample four rare desert fishes for his MS, which he received in May 2002. He is currently employed in the Ukraine as a research biologist for the Institute of Fisheries of the Ukrainian Academy of Agrarian Sciences

Chad Teal

Chad Teal received his master’s degree in Aquaculture from the University of Miami. His research in Florida focused on the sustainability of marine finfish aquaculture and recirculating aquaculture system design. Chad went on to become the technical director and lead educator for an environmental education center he helped develop called the Miami Science Barge. Chad has extensive experience in aquatic science research, living system design and construction, and public outreach and education. Chad’s doctoral research at the University of Arizona focused on developing genetic methods to control invasive populations of Red Shiner and Green Sunfish. Chad has been a member of the Bonar Lab for 4 years.

Emily Freed

Student

Larissa Lee

Larissa Lee earned a B.A. from Colby College in 2013, with majors in both Environmental Studies and Global Studies. Since 2013, she has worked with fish populations in Wyoming, Montana, and Idaho. In Wyoming, she helped to remove invasive lake trout from Yellowstone Lake in Yellowstone National Park. Larissa spent a year working as an AmeriCorps member at Trout Unlimited, where she developed a restoration strategy for a degraded watershed in Montana. In Idaho, she monitored salmonid populations as a fisheries technician for Idaho Fish and Game. Larissa came to the University of Arizona in 2016 to complete her M.S. in Natural Resources, with a focus on fisheries conservation and management. As a graduate research assistant at the University of Arizona, Larissa is developing habitat suitability criteria for native and nonnative species in multiple Arizona rivers and streams. She is also examining the relationship between hydrologic flow regime and fish community structure throughout these rivers and streams. Her research will inform fisheries managers on how to best protect flow regime to promote the success of native fish populations. 

Morgan Brizendine

Morgan Brizendine received a B.S. in Fisheries Science from Virginia Tech in Blacksburg, Virginia. She is currently pursuing an M.S. in Natural Resources with a concentration in fisheries management and conservation at the University of Arizona. Morgan's work focuses on the use of ultrasonic imaging and Ovaprim® to evaluate humpback chub Gila cypha egg maturation in the main stem Colorado River in the Grand Canyon downstream of Glen Canyon Dam. Humpback chub are an endangered species of fish endemic to the Colorado River basin. The development of non-lethal methods to assess egg maturation in female humpback chub could provide critical information biologists need to continue management of this species.

Stephani Clark-Barkalow

Stephani Clark-Barkalow received a BS in Conservation Biology from the University of New Mexico. Stephani came to the University of Arizona to obtain a Master's degree studying total suspended sediment tolerance and effects of border patrol activity on Yaqui chub, a minnow on both U.S. and Mexican endangered species lists. This work will be used by the U.S. Fish and Wildlife Service and U.S. Border Patrol to minimize, where possible, any affects to the rare fishes found on the border. Stephani's project allowed her to work on both sides of the U.S./Mexican international border with biologists and private landowners. Stephani graduated in May 2014 and went to work for American Southwest Ichthyological Researchers in Albuquerque, NM as a fisheries biologist studying endangered fishes of the Colorado River Basin.

Jack Ruggirello

Jack Ruggirello received a BS in Conservation Biology with a minor in chemistry at the State University of New York College at Cortland. While at SUNY Cortland, he participated in two fisheries management internships in which he developed a strong passion for fisheries. After, he acquired a two year lab tech position with the USGS Great Lakes Science Center at Tunison Laboratory of Aquatic Science. During this time he decided to continue his education at the University of Arizona and pursue an MS in fisheries. His thesis work involves learning about the environmental and behavioral aspects of spawning in a critically endangered minnow, Moapa dace. Through his work on developing a captive rearing and breeding protocol for fisheries managers, he has been the first to hold this unique fish in captivity for any length of time, and is the first to observe spawning of this fish in the wild through his use of high-speed videography.

Justin Mapula

Justin Mapula recieved a Bachelor's degree at New Mexico State University and then came to the University of Arizona to obtain a MS degree studying a possible larval food bottleneck to the endangered Devils Hole Pupfish. The Devils Hole pupfish is a highly-endangered species found in a isolated spring and cavern system in Death Valley National Park. Both US Fish and Wildlife Service and National Park Service biologists want to find which factors limit their population. Justin held four leadership positions in the student chapters of the American Fisheries Society and Wildlife Society where he gained experience with a variety of species, government agencies, and public interest groups. He is currently employed by the U.S. Forest Service as a fisheries biologist in Shasta, California.

Scott Rogers

Scott Rogers (right) received a BA at the University of Montana. Scott worked with Arizona Game and Fish Department and USGS Grand Canyon Monitoring and Research Center biologists to study spawning and recruitment of flannelmouth suckers in the tailwater of Glen Canyon Dam, Colorado River. This information was important for agencies managing native fishes in the Grand Canyon in the face of lowered water temperatures below the dam, desication and presence of nonnative species. Following his MS work, Scott worked at the Grand Canyon as a research biologist for the Arizona Game and Fish Department. Currently he is a Fisheries Program Manager for the Arizona Game and Fish Department in Flagstaff, Arizona.

Yuliya Kuzmenko

Dr. Yuliya Kuzmenko (sitting) was a visiting scholar from Zaporizhzha National University, Ukraine, where she has gained extensive experience in fisheries management of freshwater reservoirs and the evolution of populations of non-native species in new conditions. Yuliya lended her Eastern European experience to develop mechanical removal methods for invasive populations of northern pike (Esox lucius) in Arizona reservoirs. Northern pike can decimate populations of other fishes in lakes if illegally introduced, and management strategies for agencies are important. Prior to her arrival in Arizona, Yuliya was an Assistant professor at Zaporozhzhya State University where she lectured and performed fisheries research. She also worked as a fisheries researcher for the Ukraine State Ministry of Agricultural Policy, conducting research on fish spawning, fecundity, and population structure. Yuliya completed her Ph.D. in Ichthyology in 2004 with a dissertation on commercial fisheries of the Kakhovka reservoir. She emigrated from the Ukraine, and is currently employed as fisheries biologist in British Columbia, Canada.

Ann Widmer

Ann Widmer got her Bachelor's degree in Biology at the University of Colorado at Boulder and worked with the Colorado Division of Wildlife before coming to the University of Arizona to work on her Master's degree. Her MS project involved determining the upper temperature tolerance of loach minnow (Tiaroga cobits), a threatened species endemic to the Gila River basin. She accomplished this using 3 different methods, each of which measured slightly different aspects of thermal stress. Because traditional temperature tolerance tests poorly mimic natural stream temperature regimes, Ann worked with Cori Carveth to build a laboratory with computerized temperature control that could test tolerance under diurnal temperature fluctuations. This information was important for management agencies to understand the thermal tolerances of various fishes in the southwestern United States, and manage water bodies accordingly. Ann graduated with an MS from the University of Arizona and is currently employed as an aquatic ecologist at SWCA Environmental Consultants.

Cristina Velez

Cristina Velez got her undergraduate education at the University of Texas as Austin and at the University of Nevada Las Vegas. She worked on her MS on a project with Laura Leslie, studying the impacts of introduced fishes on native fishes in the Verde River, Arizona. Cristina investigated the distribution of native and nonnative fishes in the river and their habitat use. She used this information and information from Laura Leslie's study to calculate the total impact of introduced predators on native fishes by species, environment type, time of year and size class. This information is used by the US Fish and Wildlife Service and the Arizona Game and Fish Department to manage the river's fish communities. Cristina graduated January 2004. She worked as an endangered species biologist for the National Park Service at Lake Mead National Recreation Area and now works for the U.S. Goverment in Brazil as a USAID Environment Officer.

Laura Leslie

Laura Leslie got her BS at the University of Wyoming and worked for Wyoming Game and Fish for a while. Her MS project at the University of Arizona was investigating the diet and consumption rates of introduced predatory fishes on native desert fishes in the Verde River, Arizona. This project was conducted to identify those introduced fish species that preyed most heavily on native desert fishes, and what types of habitats, the time of year, and what size classes were responsible for most of the predation. This information is used by the US Fish and Wildlife Service and the Arizona Game and Fish Department to manage the river's fish communities. Laura graduated in August 2003 was first employed as a Research Biologist with the Arizona Game and Fish Department, working on the Colorado River.Aquatic Ecologist and is now working as a fisheries biologist at SWCA Environmental Consultants in Cody, Wyoming.

Steven Ingram

Originally from Napa, California, Steven began working in fisheries conservation as an undergraduate intern in the Doris Duke Conservation Scholars Program at Cornell University. After graduating, he worked as a fisheries technician for the Oregon Department of Fish and Wildlife and as a fisheries observer for the NOAA Fisheries Groundfish Observer Program. Steven then pursued a Master's degree in Natural Resources at the University of Arizona. His graduate research involved evaluating hydroacoustics and age and growth techniques as methods that could potentially enhance the Arizona Game and Fish Department's routine monitoring of warmwater fisheries in Arizona reservoirs. He now works as a fish biologist for the U.S. Fish and Wildlife Service in Whiteriver, Arizona.

Taylor Ulrich

Taylor Ulrich received his Bachelors of Science in Natural Resource with an emphasis in Fisheries Management and Conservation. He received a Masters of Science in Natural Resource with an emphasis in Fisheries Management and Conservation with AZCFWRU. His research project analyzed methods to maximize the impact of video presentations designed for public. These methods included considerations such as video duration, types of music, and the incorporation of psychological principles. The videos and research were completed using footage captured from arid environments in Nevada and Death Valley and  featured cryptic desert fishes and other aquatic organisms. Taylor also created a guide based on his research results that is intended for other biologists to use that will inform them on how to effectively use videography in their own areas of expertise.

Zach Nemec

Zach Nemec grew up in the greater Cleveland area of Ohio. He attended his undergraduate at Hiram College, a small liberal arts school in Northeast Ohio. During his undergraduate career, Zach conducted research in Dr. Jennifer Clark’s stream ecology lab. He focused on how channel reconfiguration affected the macroinvertebrate community and ecosystem function in a low order stream.  Zach was also a part of the Doris Duke Conservation Scholars Program at Northern Arizona University. All through his time as a scholar, he interned with U.S.G.S. Grand Canyon Monitoring and Research Center and UC San Diego Scripps Institution of Oceanography. After receiving his Bachelor of Arts degree in spring 2016, he started his graduate assistantship at the University of Arizona with Dr. Scott Bonar.  Zach’s research consists of developing habitat suitability criteria for both native and nonnative fish species in several medium size rivers in central Arizona. In addition, he is investigating the role of riparian vegetation has on fish communities.   

Roy Ulibarri

Roy Ulibarri received a BS in Zoology with a minor in Botany from Western New Mexico University. Having worked his summer seasons with the U.S. Fish and Wildlife on Apache trout recovery and non-native species removal he decided to pursue a MS in fish conservation and management at the University of Arizona. Roy's work is focused on determining suitable and preferred habitat for the Zuni bluehead sucker. There is not much known about the ecological requirements of the Zuni bluehead sucker. Roy will be developing habitat criteria for Zuni bluehead sucker to improve the ability of the FWS and others to conserve the species, and help prevent losses due to inadequate information.

Sally Petre

Sally Petre received her Bachelor of Science degree in Environmental Science with minors in Fisheries Sciences and Wetland Assessment from North Carolina State University. While at North Carolina State University she studied mercury contamination in six marine species that are commonly caught and consumed in North Carolina. To support decisions about local, sustainable fish consumption, these data were compared to EPA, FDA, and Seafood Watch List consumption recommendations. Currently, Sally is completing her Master's degree studying habitat suitability for Apache Trout, a native endemic species to the White Mountains and Virile crayfish, a non-native species. Sally has been very active with the American Fisheries Society and volunteers with Arizona Game and Fish and US Fish and Wildlife Service to gain a diversity of experiences from teaching school groups about fishing and ecology to working with endangered fishes of the Grand Canyon. Sally has accepted a position with the Arizona Game and Fish Department as a Sport Fish Research Biologist and is excited to continue working in Arizona!

Colleen Svancara

Colleen Svancara is a graduate student at the University of Arizona's School of Natural Resource Program, and is approaching a Masters Degree in Natural Resource Studies. Colleen is a native of Tucson, Arizona. She obtained her bachelor's degree in May 2013 at the University of Arizona in Conservation Biology. Colleen is working with Scott and professors Laura Lopez-Hoffman and George Ruyle on a large, comprehensive project on jaguar conservation in southern Arizona. The U.S. Fish and Wildlife Service has contracted the help of the university in conducting research on attitudes of the ranchers of southeastern Arizona and how educational outreach can be a useful tool in encouraging conservation. Colleen's research entails interviewing ranchers about their opinions and perspectives towards jaguar conservation. This data will inform the design of outreach workshops to be held in late 2014, open to all southern Arizona ranchers. The main goal is to use different education methods to assess changes in rancher perception and knowledge of jaguar conservation.

Ambre Chaudoin

Ambre Chaudoin completed a B.S. in Wildlife, Fish and Conservation Biology from the University of California, Davis. She has extensive ecological research experience, dealing in a variety of freshwater and marine ecosystems through work experience with organizations and institutions such as UC Davis, Bodega Marine Laboratory, Monterey Bay Aquarium, The Marine Mammal Center, and Wildlife Center of Silicon Valley. Ambre is currently working on an MS degree at the University of Arizona in collaboration with the US Geological Survey, the US Fish and Wildlife Service the National Park Service, and the Devils Hole pupfish Recovery Team on aspects of the conservation and recovery of the critically endangered Devils Hole pupfish. Her research specifically focuses on investigating the factors that drive reproduction of the Devils Hole pupfish with implications for management in the wild population as well laboratory propagation applications.

Andrew Schultz

Andrew Shultz is an Arizona native, and has many years experience working with desert fishes. Andy received both his BS and his MS at the University of Arizona on desert fisheries-related issues. Andy led the UA effort to coordinate with several agencies to remove the imperiled Gila Chub (Gila intermedia) from Sabino Canyon before the advancing Aspen Fire destroyed its habitat. The rescue effort was successful, and was featured on several local and national news outlets. Andy finished his PhD on methods to culture and rear Gila Chub at the University of Arizona and is currently employed as a Fish Research Biologist by the U.S. Bureau of Reclamation at the Tracy Fish Collection Facility located in the Central Valley of California.

Alison Iles

Alison Iles was the lab's research specialist for several years, working with Scott as a lead researcher on the North American freshwater fish standard sampling project. This assignment involved contacting various state / provincial and federal fish and wildlife agencies across North America to obtain and compile data on fisheries indices for common species of fish. Alison also coordinated and executed field research examining the relationship of Asian tapeworm infection rates with habitat and biological factors. Following her work at the University of Arizona, Alison obtained a Ph.D. in Marine Sciences at Oregon State University and is currently employed there as a postdoctoral researcher. Alison came to Arizona after completing a B.Sc. in Environmental Science and a M.Sc. in Aquatic Ecology at McGill University, Montreal, Canada.

Jason Kline

Jason Kline moved to Tucson from Tennessee in October of 2003, where he earned his B.S. at Tennessee Technological University in Marine and Fisheries Biology. He studied effects of a non-native parasite, the Asian tapeworm, on endangered desert fishes of the Rio Yaqui. Effects of Asian tapeworm on rare desert fishes were needed so agency biologists can understand how to better conserve the fishes. He also developed methods to propagate the endangered Yaqui chub and Yaqui topminnow, the first time ever in captivity. Following graduation, Jason was employed as a Fisheries Specialist with the Arizona Game and Fish Department, and then moved to Denver where he is now a biologist at SWCA Environmental Consultants.

Jon Flinders

Jon Flinders received a BS degree at Utah State University and worked with the Utah Division of Wildlife on the fisheries at Bear Lake for a time. He came to the University of Arizona to study the effects of introduced northern pike on Arizona fish communities. Northern pike are currently in only a few lakes in Arizona, and illegal introductions by the public have expanded their distribution, even to within 5 miles of the Mexican border. Jon worked closely with the Arizona Game and Fish Department to study the impacts of this top piscivore. Jon graduated December 2004, was first employed as a district biologist in Yuma with the Arizona Game and Fish Department, then went to the University of Arkansas to obtain a Ph.D. He is currently employed as a research fisheries biologist with the Idaho Department of Fish and Game.

David Ward

David Ward is an Arizona native and has conducted a variety of fisheries research in the Southwest. He received a BS degree in Zoology from Brigham Young University and a MS in Fisheries Science from the University of Arizona. David studied the effects of temperature on the swimming ability of native fishes in the Grand Canyon for his MS work. This work provides information for agencies managing temperatures of the Colorado River below Glenn Canyon Dam. David first worked for the Arizona Game and Fish Department as a Grand Canyon fisheries biologist and managed a hatchery research station for Arizona Game and Fish Department. He is now employed as a fisheries biologist studying the Grand Canyon with the U.S. Geological Survey's Grand Canyon Monitoring and Research Center. David’s research activities focus on interactions between native and nonnative fish species with an emphasis on conservation of native Colorado River fishes.