University of California, Riverside

Environmental Sciences

Daniel Schlenk

Daniel Schlenk

Daniel Schlenk Photograph

Professor of Aquatic Ecotoxicology

Academic Degrees:

  • Ph.D. Oregon State University, 1989
  • B.S. Northeast Louisiana University, 1984


  • His research focuses on understanding the biochemical factors that influence susceptibility to environmental and natural chemicals. Three specific projects involve the impact of climate change on environmental factors that influence detoxification strategies in aquatic organisms; mechanistic investigations of the effects of salinity on pesticide toxicity in fish; and the role of biotransformation as a mechanism of tolerance to natural and man-made toxic agents.

Research Group:

  • Graduate Students
  • Other
    • Jordan Crago - Ph.D., Postdoctoral Research Associate

Representative Publications:

  • M. L. Brooks, E. Fleishman, L. R. Brown, P. H. Lehman, I. Werner, N. Scholz, C. Mitchelmore, J. R. Lovvorn, M. L. Johnson, D. Schlenk, S. van Drunick, J. I. Drever, D. M. Stoms, A. E. Parker, and R. Dugdale (2012) Life Histories, Salinity Zones, and Sublethal Contributions of Contaminants to Pelagic Fish Declines Illustrated with a Case Study of San Francisco Estuary, California, USA. Estuaries and Coasts 35:603-621.
  • R. Lavado, D. Shi, and D. Schlenk (2012) Effects of salinity on the toxicity and biotransformation of l-selenomethionine in Japanese medaka (Oryzias latipes) embryos: Mechanisms of oxidative stress. Aquatic Toxicology 108:18-22.
  • N. L. Scholz, E. Fleishman, L. Brown, I. Werner, M. L. Johnson, M. L. Brooks, C. L. Mitchelmore, and D. Schlenk (2012) A perspective on modern pesticides, pelagic fish declines, and unknown ecological resilience in highly managed ecosystems. Bioscience 62:428-434.
  • V. Lorenzi, A.C. Mehinto, N. Denslow, and D.Schlenk (2012) Effects of exposure to the B-blocker propranolol on the reproductive behavior and gene expression of the fathead minnow, Pimephales promelas. Aquatic Toxicology 116:8-15.
  • D. Bulloch, R. Lavado, K. Forsgren, S. Beni, D. Schlenk, C. Larive, (2012) Analytical and Biological Characterization of Halogenated Gemfibrozil Produced through Wastewater Chlorination. Environmental Science and Technology 46:5583-5589.
  • Jesus A. Reyes, Doris E. Vidal-Dorsch, Daniel Schlenk, Steven M. Bay, Jeffrey L. Armstrong, Joseph R. Gully, Curtis Cash, Michael Baker, Timothy D. Stebbins, Gary Hardiman, and Kevin M. Kelley (2012) Evaluation of reproductive endocrine status in hornyhead turbot sampled from Southern California's urbanized coastal environments. Environmental Toxicology and Chemistry 31:2689-2700.
  • K. L. Forsgren, X. Deng, G.-H. Lu, S. M. Bay, D. E. Vidal-Dorsch, J. Armstrong, J. R. Gully, D. Schlenk (2012) Annual and seasonal evaluation of reproductive status in hornyhead turbot at municipal wastewater outfalls in the southern California bight. Environmental Toxicology and Chemistry 31:2701-2710.
  • Steven M. Bay, Doris E. Vidal-Dorsch, Daniel Schlenk, Kevin M. Kelley, Keith A. Maruya, and Joseph R. Gully. (2012) Integrated coastal effects study: Synthesis of findings. Environmental Toxicology and Chemistry 31: 2711-2722.
  • J. Finn, M.Hui, V. Li, V. Lorenzi, N. de la Paz, S. H. Cheng, L.L. Chan, D.Schlenk (2012). Effects of propranolol on heart rate and development in Japanese meaka (Oryzias latipes) and zebrafish (Danio rerio). Aquatic Toxicology 122-123: 214-221.
  • D. Schlenk, R. Lavado, J. Loyo-Rosales, W. Jones, L. Maryoung, N. Riar, I. Werner, and D. Sedlak (2012). Reconstitution Studies of Pesticides and Surfactants Exploring the Cause of Estrogenic Activity Observed in Surface Waters of the San Francisco Bay Delta. Environmental Science & Technology 46: 9106-9111.
  • M.H. Gjernes, D.Schlenk, A. Arukwe (2012) Estrogen receptor-hijacking by dioxin-like 3,3’,4,4’-pentachlorobiphenyl (PCB126) in salmon hepatocytes involves both receptor activation and receptor protein stability. Aquatic Toxicology 124-125:197-208.
  • R. Lavado, R. Aparicio-Fabre, and D.Schlenk (2013) Effects of salinity acclimation on the pesticide metabolizing enzyme flavin-containing monooxygenase (FMO) in rainbow trout (Oncorhynchus mykiss). Comparative Biochemistry and Physiology Part C 157:9-15.
  • J.E. Drewes, P. Anderson, N. Denslow, A. Olivieri, D.Schlenk, S.A. Snyder, and K.A. Maruya (2013) Designing monitoring programs for chemicals of emerging concern in potable reuse- what to include and what not to include? Water Science and Technology 67:433-439.
  • K.L. Forsgren, N. Riar, D.Schlenk (2013) The effects of the pyrethroid insecticide, bifenthrin, on steroid hormone and gonadal development of steelhead (Oncorhynchus mykiss) under hypersaline conditions. General and Comparative Endocrinology 186:101-107.
  • Edward P. Kolodziej, Shen Qu, Kristy L. Forsgren, Sarah A Long, James B.Gloer,; Gerrad D.Jones,; Daniel Schlenk, Jonas Baltrusaitis, David M. Cwiertny (2013) Identification and Environmental Implications of Photo-Transformation Products of Trenbolone Acetate Metabolites. Environmental Science and Technology 47:5031-5041.
  • Lian-Jun Bao, Fang Jia, Jordan Crago, Eddy Y. Zeng, Daniel Schlenk, Jay Gan (2013) Assessing Bioavailability of DDT and Metabolites in Marine Sediments Using Solid Phase Microextraction with Performance Reference Compounds. Environmental Toxicology and Chemistry 32:1946-1953.
  • Doris E. Vidal-Dorsch, Steven M. Bay, Cataldo Ribecco, L. James Sprague, Mila Angert, Colleen Ludka, Oliana Carnevali, Darrin J. Greenstein, Daniel Schlenk, Kevin M. Kelley, Jesus A. Reyes, Shane Snyder, Brett Vanderford, Lan C. Wiborg, Dawn Petschauer, Roman Sasik, Michael Baker, Gary Hardiman (2013) Genomic and phenotypic response of hornyhead turbot exposed to municipal wastewater effluents. Aquatic Toxcicology 140-141:174-184.
  • Brant Jorgenson, Erica Fleishman, Kate MacNeale, Daniel Schlenk, Nathaniel Scholz, Julann Spromberg, Inge Werner, Donald A. Weston, Qingfu Xiao, Thomas Young, Minghua Zhang (2013) Predicted Transport Of Pyrethroid Insecticides From An Urban Landscape To Surface Water. Environmental Toxicology and Chemistry 32:2469-2477.
  • Michael E. Baker, Doris E. Vidal-Dorsch,, Cataldo Ribecco, L. James Sprague, Mila Angert, Narimene Lekmine, Colleen Ludka, Andrea Martella, Eugenia Ricciardelli, Steven M. Bay, Joseph R. Gully, Kevin M. Kelley, Daniel Schlenk, Oliana Carnevali, Roman Šášik , Gary Hardiman (2013) Molecular analysis of endocrine disruption in hornyhead turbot at wastewater outfalls in Southern California using a second generation multi-species microarray. PLOS ONE 8(9) e75553 1-16.
  • Navneet Riar, Lindley Maryoung, and Daniel Schlenk (2013) Effects of salinity acclimation on the endocrine disruption and acute Toxicity of bifenthrin in freshwater and euryhaline strains of Oncorhynchus mykiss. Environmental Toxicology and Chemistry (in press).
  • Keith Maruya, Paul Anderson, Nancy Denslow, Jorg Drewes, Adam Olivieri, Geoff Scott, Shane Snyder, Daniel Schlenk (2013) An Adaptive, Comprehensive Monitoring Strategy for Chemicals of Emerging Concern (CECs) in California’s Aquatic Ecosystems. Integrated Environmental Assessment and Management (in press).
  • Ramon Lavado, Roseaura Aparicio-Fabre, Daniel Schlenk (2013) Effects of salinity acclimation on the expression and activity of Phase I enzymes (CYP450 and FMOs) in coho salmon (Oncorhynchus kisutch). Fish Physiology and Biochemistry (in press).

Courses Taught:

  • ENTX 101 Fundamentals of Toxicology
  • ENTX 208/ENSC 208 Ecotoxicology
  • ENTX 205 Biotransformation of Organic Chemicals
  • ENSC 001 Introduction to Natural Resources
  • ENSC 191 Seminar in Professional Development

Graduate Program Affiliations and Research Focus Areas:

Honors and Awards

Dr. Schlenk’s honors include his selection as a Fellow of AAAS, as the Chair of USEPA - FIFRA Science Advisory Panel and appointments as a Ray Lankester Fellow at the Marine Biological Association of the United Kingdom, a visiting scholar at the Chinese University of Hong Kong, the Instituto Del Mare in Venice, Italy, the CSIRO Laboratory in Lucas Heights, Australia, and Distinguished Visiting Professor at the State Key Laboratory of Marine Science at Xiamen University, China.


More Information

General Campus Information

University of California, Riverside
900 University Ave.
Riverside, CA 92521
Tel: (951) 827-1012

Department Information

Environmental Sciences
Geology 2258

Tel: (951) 827-5116
Fax: (951) 827-3993