University of California, Riverside

Environmental Sciences

Daniel Schlenk

Daniel Schlenk

Daniel Schlenk Photograph

Department Vice Chair
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. Four 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; the role of biotransformation as a mechanism of tolerance to natural and man-made toxic agents; impacts of endocrine disrupting chemicals on aquatic organisms; and mechanisms of PAH developmental toxicity in fish.

Research Group:

    Representative Publications:

    • Jordan Crago and Daniel Schlenk (2015) The effect of bifenthrin on the dopaminergic pathway in juvenile rainbow trout (Oncorhynchus mykiss). Aquatic Toxicology 162:66-72.
    • Gabriela Rodríguez-Fuentes, Fernando J. Rubio-Escalante, Elsa Noreña-Barroso, Karla S. Escalante-Herrera, Daniel Schlenk (2015) Impacts of oxidative stress on acetylcholinesterase transcription, and activity in embryos of zebrafish (Danio rerio) following chlorpyrifos exposure. Comparative Biochemistry Physiology 172-173:19-25.
    • Thiago Scremin Boscolo Pereira, Camila Nomura Pereira Boscolo, Danilo Grünig Humberto da Silva, Sergio Ricardo Batlouni, Daniel Schlenk, Eduardo Alves de Almeida (2015) Anti-androgenic activities of diuron and its metabolites in male Nile tilapia (Oreochromis niloticus). Aquatic Toxicology 164:10–15.
    • Alvine C. Mehinto, Ai Jia, Shane A. Snyder, B. Sumith Jayasinghe, Nancy D. Denslow, Jordan Crago, Daniel Schlenk, Christopher Menzie, Sandy D. Westerheide, Frederic D.L. Leusch, Keith A. Maruya (2015) Interlaboratory comparison of in vitro bioassays for screening of endocrine active chemicals in recycled water. Water Research 83:303-309.
    • Lindley A. Maryoung, Ramon Lavado, Theo K. Bammler, Evan P. Gallagher, Patricia L. Stapleton, Richard P. Beyer, Federico M. Farin, Gary Hardiman, Daniel Schlenk (2015) Differential Gene Expression in Liver, Gill, and Olfactory Rosettes of Coho Salmon (Oncorhynchus kisutch) After Acclimation to Salinity. Marine Biotechnology 17:703-717.
    • Varenka Lorenzi, Ree Choe, Daniel Schlenk (2016) Effects of environmental exposure to diazepam on the reproductive behavior of fathead minnow, Pimephales promelas. Environmental Toxicology 31: 561–568.
    • Keith A. Maruya, Nathan G. Dodder, Alvine C. Mehinto, Nancy D. Denslow, Daniel Schlenk, Shane A. Snyder and Stephen B. Weisberg (2016) A tiered, integrated biological and chemical monitoring framework for contaminants of emerging concern (CECs) in aquatic ecosystems. Integrated Environmental Assessment and Management 12(3), 540-547.
    • Aileen Maldonado, Amber Johnson, Deborah Gochfeld, Marc Slattery, Gary K. Ostrander, Jon-Paul Bingham, Daniel Schlenk (2016) Hard Coral (Porites lobata) extracts and homarine on Cytochrome P450 expression in Hawaiian butterflyfishes with different feeding strategies. Comparative Biochemistry and Physiology 179:57-63.
    • Geoffrey Ivan Scott, Dwayne E. Porter, G. Tom Chandler, R. Sean Norman, C. Hart Scott, Miguel Ignacio Uyaguari-Diaz, Keith Maruya, Steve B. Weisberg, Michael H. Fulton, Ed F. Wirth, Janet Mooore, Paul L. Pennington, Daniel Schlenk, George P. Cobb, Nancy D. Denslow (2016) Antibiotics as CECs: An Overview of the Hazards Posed by Antibiotics and Antibiotic Resistance. Frontiers in Marine Science 3:24. doi: 10.3389/fmars.2016.00024.
    • Allison Kupsco Daniel Schlenk (2016) Stage susceptibility of Japanese medaka (Oryzias latipes) to selenomethionine and hypersaline developmental toxicity. Environmental Toxicology and Chemistry 35:1247-1256.
    • Jordan Crago, Cindy Bui, Sanji Grewal, Daniel Schlenk (2016) Age-Dependent Effects in Fathead Minnows from the anti-diabetic drug Metformin. General and Comparative Endocrinology 232: 185-90.
    • Thiago Scremin Boscolo Pereira, Camila Nomura Pereira Boscolo, Andreia Arantes Felício, Sergio Ricardo Batlouni, Daniel Schlenk, Eduardo Alves de Almeida (2016) Estrogenic activities of diuron metabolites in female Nile tilapia (Oreochromis niloticus). Chemosphere 146:497-502.
    • Shirin Mesbah Oskul, Graciel Diamante, Chunyang, Liao, Wei, Shi, Jay Gan, Daniel Schlenk, William H. Grover (2016) Assessing and reducing the toxicity of 3-D printed parts. Environmental Science and Technology Letters 3:1-6.
    • Augustine Arukwe, Jan Myburgh, Håkon A. Langberg, Aina O. Adeogun, Idunn Godal Braa, Monika Moeder, Daniel Schlenk, Jordan Paul Crago, Francesco Regoli, Christo Botha (2016) Developmental alterations and endocrine-disruptive responses in farmed Nile crocodiles (Crocodylus niloticus) exposed to contaminantsfrom the Crocodile River, South Africa. Aquatic Toxicology 173: 83-93.
    • Jordan Crago, Elvis Genbo Xu, Allison Kupsco, Fang Jia, Alvine C. Mehinto, Wenjian Lao, Keith A. Maruya, Jay Gan and Daniel Schlenk (2016). Trophic transfer and effects of DDT in male hornyhead turbot (Pleuronichthys verticalis) from Palos Verdes Superfund site, CA (USA) and comparisons to field monitoring. Environmental Pollution 213:940-948.
    • Elvis Genbo Xu, Cindy Bui, Cassandra Lamerdin, Daniel Schlenk (2016). Spatial and temporal assessment of environmental contaminants in water, sediments and fish of the Salton Sea and its two primary tributaries, California, USA, from 2002-2012. Science of the Total Environment 559:130–140.
    • Aileen Maldonado, Ramon Lavado, Sean Knuston, Marc Slattery, Sridevi Ankisetty, Jared V Goldstone, Kayo Watanabe, Eunha Hoh, Rama S Gadepalli, John M. Rimoldi, Gary K. Ostrander, Daniel Schlenk (2016) Biochemical Mechanisms for Geographical Adaptations to Novel Toxin Exposures in Butterflyfish. PLOS one Volume: 11 Issue: 5: e0154208.
    • Elvis Genbo Xu, Edward M. Mager, Martin Grosell, Christina Pasparakis, Lela S. Schlenker, John D. Stieglitz, Daniel Benetti, E.Starr Hazard, Sean M. Courtney, Graciel Diamante, Juliane Freitas, Gary Hardiman, Daniel Schlenk (2016) Time- and oil-dependent transcriptomic and physiological responses to Deepwater Horizon oil in mahi-mahi (Coryphaena hippurus) embryos and larvae. Environmental Science and Technology 50: 7842-7851.
    • Allison Kupsco, Daniel Schlenk (2016) Molecular Mechanisms of Selenium-Induced Spinal Deformities in Fish. Aquatic Toxicology 179:143-150.
    • Susanne M. Brander, Molly K. Gabler, Nicholas L. Fowler, Richard E. Connon, and Daniel Schlenk (2016) Pyrethroid pesticides as endocrine disruptors: Molecular mechanisms in vertebrates with a focus on fishes. Environmental Science and Technology 50:8977-8992.
    • Andréia A. Felício, Jordan Crago, Lindley A. Maryoung, Eduardo A. Almeida, Daniel Schlenk (2016). Effects of alkylphenols on the biotransformation of diuron and enzymes involved in the synthesis and clearance of sex steroids in juvenile male tilapia (Oreochromus mossambica). Aquatic Toxicology 180:345-352.
    • Juliane, Freitas, Allison Kupsco, Graciel Diamante, Andreia Felicio, Eduardo Alves de Almeida, Daniel Schlenk (2017) Influence of temperature on the thyroidogenic effects of Diuron and its metabolite 3,4-DCA in tadpoles of the American bullfrog (Lithobates catesbeianus). Environmental Science and Technology (in press).
    • Allison Kupsco, Daniel Schlenk (2017) Developmental Expression and Regulation of Flavin-containing monooxygenase by the Unfolded Protein Response in Japanese Medaka (Oryzias latipes). Comparative Biochemistry and Physiology C. 191:7-13.
    • Allison Kupsco, Daniel Schlenk (2017) Comparative developmental toxicity of desalination brine and sulfate-dominated saltwater in a euryhaline fish. Archives of Environmental Contamination and Toxicology (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 is a Fellow of the American Association for the Advancement of Science since 2010, and from 2007-2014, he was a permanent member of the USEPA FIFRA Science Advisory Panel which he chaired from 2012-2014. From 2003-2006, he was a member of the Board of Directors for the North American Society of Environmental Toxicology and Chemistry. He was co-editor-in chief of Aquatic Toxicology from 2005-2011, and still serves on the editorial board of Aquatic Toxicology as well as Toxicological Sciences, and Marine Environmental Research. He has been a recipient of the Ray Lankester Investigatorship of the Marine Biological Association of the United Kingdom; a visiting Scholar of the Instituto Del Mare, Venice Italy; a visiting Scholar in the Department of Biochemistry, Chinese University of Hong Kong; a Visiting Scientist at the CSIRO Lucas Heights Laboratory, in Sydney Australia, a Distinguished Fellow of the State Key Laboratory for Marine Environmental Science of Xiamen University, China, and a Visiting Professor Fellow of the National Counsel of Technological and Scientific Development at the University of Sao Jose Rio Preto, Brazil . He has been an ad hoc member for the USEPA Science Advisory Board for Aquatic Life Criteria Guidelines from the Ecological Processes and Effects Committee, and has participated in proposal review panels for the NSF, USEPA, NOAA, and the National Institute of Environmental Health Sciences.


    More Information

    General Campus Information

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

    Department Information

    Environmental Sciences
    Geology 2460

    Tel: (951) 827-5116
    Fax: (951) 827-4652