Skip Top Navigation

Research Staff

Our research staff are as diverse as the projects they work on. Whether they are conducting water quality monitoring or presenting research results at a national conference, our staff share a common goal—to further understanding of the environment through research, education, and outreach.

George Guillen

Executive Director, Environmental Institute of Houston
Professor of Biology and Environmental Science, CSE

Guillen is the executive director of EIH and a professor of biology and environmental science at UHCL. Guillen obtained his Ph.D. in environmental science from the University of Texas, School of Public Health. His previous experience includes chief of the Fisheries and Contaminants Program at the U.S. Fish and Wildlife Service office in Arcata, Calif. Prior to that he was the toxicology and risk assessment unit chief at the Minerals Management Service in New Orleans, La. Additionally, he worked for 10 years with the TCEQ predecessor agencies (TNRCC and TWC) as district manager and program manager. He also served as a biologist with the Texas Parks and Wildlife Department for more than four years.

Staff Bio

George is holding an American oystercatcher. He is smiling and is looking into the distance to his right.

Jenny Oakley

Associate Director, Research Programs

Oakley is EIH's associate director of research programs and has worked for EIH since 2008. She earned a Ph.D. in the Marine Biology Interdisciplinary Graduate Program at Texas A&M University in 2019. Her M.S. and B.S. degrees are in biology (minor in chemistry) from TAMU-Corpus Christi. Oakley manages EIH's research programs, working closely with EIH research staff to coordinate proposal development, project management, and report compilation. She is also one of EIH's licensed OUPV captains.

Staff Bio

Jenny is smiling to the camera. She is holding a large fish out in front of her.

Aurora Alvarez

Research Technician

Alvarez is a research technician at EIH. She graduated from University of Nebraska- Lincoln with a B.S in fisheries and wildlife in 2019. She assists on the statewide NRSA project.

Staff Bio

Aurora is wearing a black sun visor and smiling at the camera. A stream and trees are in the background.

Kaylei Chau

Research Associate

Chau is a research associate at the Environmental Institute of Houston. She graduated from UHCL with her B.S. in environmental science with a specialization in biology in the spring of 2017. Currently, she is pursuing a master's degree, and will be focusing on floating wetland treatment systems for her thesis project.

Staff Bio

Kaylei is wearing a pink cap. She is smiling at the camera. A rocky hillside and trees are in the background.

Noah Daun

Research Associate

Daun is a research associate at EIH. He graduated from UW–Stevens Point with a B.S. in May 2019. He graduated with an M.S. from University of Southern Mississippi in May 2023. His thesis focused on the habitat preferences of the freckled darter and variation of fish species assemblages in woody habitats of large rivers. He is currently the fish taxonomist for Texas on the NRSA project.

Staff Bio


Mandi Gordon

Senior Biologist

Gordon began working for EIH as a research associate in 2011. She obtained her M.S. in biology from Georgia Southern University and her B.S. in marine biology from Texas A&M University at Galveston. Her prior experience covers broad topics such as examination of physiological adaptations, biomechanics, ecological and environmental impacts on populations, and reproductive endocrinology. Gordon has had the opportunity to work with a wide range of vertebrate species, but her primary senior research role at EIH involves the study of turtles. Since working for EIH, she has participated in interdisciplinary projects ranging from water quality monitoring to population demographics and ecology.

Staff Bio

Mandi is outside and is smiling into the camera. She is amused by the gray tree frog sitting on the bill of her khaki-colored cap.

Marc Mokrech

Senior Research Scientist

Mockrech's background is in civil engineering specialized in geographic information systems (GIS) and remote sensing. His current research focuses on spatial modeling considering an interdisciplinary approach for analyzing and understanding future environmental and socio-economic implications. He has more than 10 years in applying spatial modeling in a wide range of fields including coastal management and adaptation to future changes, impact assessment of climate change on urban and natural environments, hydrological and watershed analysis, terrain analysis, and uncertainty management in GIS-based models. Mokrech is currently investigating changes in landscape use and demographics and impacts on the local environment.

Staff Bio

Marc looks into the distnce. He is wearing a cap and an orange sweatshirt. He is holding a drone controller. Marsh grasses and a body of water are in the background.

Ashlyn Sak

Research Technician

Sak joined the EIH team in 2022 as a research technician. She earned her B.S. in natural resource ecology and management from Louisiana State University. Her research interests include fish morphology, mutualistic relationships, climate change, and disease ecology.

Staff Bio

Close up of Ashlyn hiking White Sands.

Erica Underwood

Research Technician

Underwood is a research technician and has worked for EIH since 2022. She earned a B.S. in biology from Lindenwood University, with a minor in chemistry. Previously, she worked with the National Park Service helping to protect endangered Kemp's ridley sea turtles.

Staff Bio

Close up of Erica at the beach.


Equipment Maintenance Technician

The equipment maintenance technician is responsible for performing basic maintenance and repair of field gear that support research tasks (e.g., vessels, trailers, outboard motors, vehicles, ATVs). This position is critical to the success of our research program which is engaged in aquatic studies state-wide in Texas.

EIH Logo