Rick Relyea

Professor and Director, Pymatuning Laboratory of Ecology

Ecology & Evolution

Office: (412) 624-4656
Lab: (412) 624-4458
101 Clapp Hall
4249 Fifth Avenue
Pittsburgh, PA 15260

Ph.D., University of Michigan (1998)


Dr. Relyea is an aquatic ecologist who received his Ph.D. from the University of Michigan in 1998, under the mentorship of Dr. Earl Werner. He joined the department in 1999 and has served as the Director of the University's field station, the Pymatuning Laboratory of Ecology, since 2007.

For effective conservation, we have to understand how natural communities work and how they are affected by human impacts. To accomplish this goal, my lab works at the interface of several biological fields, including ecology, evolution, animal behavior, and ecotoxicology. By integrating our thinking (and our experiments) across these diverse biological disciplines, we can develop exciting new insights that improve our basic understanding of ecological communities and make discoveries that are important to conservation. I have applied this approach to my studies of aquatic communities. My research group works in a variety of environments (from highly controlled laboratory experiment to outdoor mesocosms and natural field sites) and we focus on a wide diversity of aquatic organisms including amphibians, fish, insects, snails, amphipods, crayfish, zooplankton, aquatic plants, and algae.

My research program can be broken down into several broad areas:

  • The effects of pesticides and nutrients on aquatic communities
  • The interaction of diseases with other natural and anthropogenic stressors
  • The impact of leaf litter inputs on wetland communities
  • Sexual selection in crustaceans
  • The ecology and evolution of phenotypic plasticity (e.g., how variation in predators, competitors, and mates induce changes in an organism's behavior, morphology, and life history)
  • Long-term monitoring of aquatic communities
Recent Publications
  • 2014

  • Ricklefs, R., and R. Relyea. 2014. Ecology:  The Economy of Nature (7th ed.). Freeman Publishers. (college textbook)

  • Benard, M. F., C. J. Davis, R. A. Relyea, D. K. Skelly, E. E. Werner, and K. Yurewicz. 2014. Is spatial synchrony predictable?  A test in an amphibian metapopulation? Proceedings of the Royal Society B __:__-__.

  • Hua, J., D. K. Jones, and R. A. Relyea. 2014. Induced tolerance from a sublethal insecticide leads to cross-tolerance to other insecticides. Environmental Science & Technology__:__-__.

  • Brogan, W. R., and R. A. Relyea. 2014. A new mechanism of macrophyte mitigation: How submerged plants reduce malathion's acute toxicity to aquatic animals. Chemosphere __:__-__.

  • Hua, J., and R. A. Relyea. 2014. Chemical cocktails in aquatic ecosystems: Pesticide effects on resistance and resilience. Environmental Pollution __:__-__.

  • Hoverman, J. T., R. D. Cothran, and R. A. Relyea. 2014. Generalist versus specialist strategies of plasticity: Snail responses to predators that have different foraging modes. Freshwater Biology __:__-__.

  • Cothran, R. D., A. B. Stoler, and R. A. Relyea. 2014. Leaves and litterbugs:  how litter quality affects the performance of freshwater amphipods. Freshwater Science __:__-__.

  • Murren, C. J., H. J. Maclean, S. E. Diamond, U. K. Steiner, M. A. Heskel, C. A. Handelsman, C. K. Ghalambor, J. R. Auld, H. S. Callahan, D. W. Pfennig, R. A. Relyea, C. D. Schlichting, and J. Kingsolver. 2014. Evolutionary change in continuous reaction norms. American Naturalist 183:453-467.pdf

  • Groner, M. L., L. A. Rollins-Smith, L. K. Reinert, J. Hempel, M. E. Bier, and R. A. Relyea. 2013. Interactive effects of competition and predator-cues on immune responses of leopard frogs at metamorphosis. Journal of Experimental Biology 217:351-358.pdf

  • Goos, J. M., B. J. French, R. A. Relyea, R. D. Cothran, and P. D. Jeyasingh. 2014. Sex-specific plasticity in somatic phosphorus content of Hyalella amphipods. Hydrobiologia 722:93-102.pdf

  • 2013

  • Hanlon, S. M., and R. A. Relyea. 2013. Sublethal effects of pesticides on predator-prey interactions in amphibians. Copeia 2013:691-698.pdf

  • Cothran, R. D., A. R. Stiff, K. Chapman, G. A. Wellborn, and R. A. Relyea. 2013. Reproductive interference via interspecific pairing in an amphipod species complex. Behavioral Ecology and Sociobiology 67:1357-1367.pdf

  • Hua, J., N. Morehouse, and R. A. Relyea. 2013. Pesticide resistance in amphibians: Induced resistance in susceptible populations, constitutive tolerance in tolerant populations. Evolutionary Applications 6:1028-1040.pdf

  • Groner, M. L., J. C. Buck, S. Gervasi, A. R. Blaustein, L K. Reinert, L. A. Rollins-Smith, M. E. Bier, J. Hempel, and R. A. Relyea. 2013. Lasting effects: Larval exposure to predators alters immune function and disease in post-metamorphic wood frogs. Ecological Applications 23:1443-1454.pdf

  • Gervasi, S. S., J. Urbina, J. Hua, T. Chestnut, R.A. Relyea, and A. R. Blaustein. 2013. Experimental evidence for differential susceptibility to the amphibian chytrid fungus (Batrachochytrium dendrobatidis) in the American bullfrog (Lithobates catesbeianus). EcoHealth 10:166-171.pdf

  • Stoler, A., and R. A. Relyea. 2013. Leaf litter quality induces morphological and developmental changes in larval amphibians. Ecology 94:1594–1603.pdf

  • Brogan, W. R., and R. A. Relyea. 2013. Mitigating with macrophytes:  Submersed plants reduce the toxicity of pesticide-contaminated water to zooplankton. Environmental Toxicology and Chemistry 31:699-706.pdf

  • Stoler, A., and R. A. Relyea. 2013. Bottom-up meets top-down:  Leaf litter inputs influence predator-prey interactions in wetlands. Oecologia 173:249-257.pdf

  • Brogan, W. R., and R. A. Relyea. 2013. Mitigation of malathion’s acute toxicity by four submersed macrophyte species. Environmental Toxicology and Chemistry 31:1535-1543.pdf

  • Hua, J., R. Cothran, A. Stoler, and R. A. Relyea. 2013. Cross-tolerance in amphibians:  Wood frog mortality when exposed to three insecticides with a common mode of action. Environmental Toxicology and Chemistry 32:932-936.pdf

  • Cothran, R. D., K. A. Henderson, D. Schmidenberg, and R. A. Relyea. 2013. Phenotypically similar but ecologically distinct: Differences in competitive ability and predation risk among amphipods. Oikos 122:1429-1440.pdf

  • Cothran, R. D., J. Brown, and R. A. Relyea. 2013. Proximity to agriculture is correlated with pesticide tolerance:  Evidence for the evolution of amphibian resistance to modern pesticides. Evolutionary Applications 6:832-841.pdf

  • 2012

  • Friedland, A., R. Relyea, and D. Courard-Hauri. 2012. Essentials of Environmental Science (1st ed.). Freeman Publishers.  (college textbook).  pdf

  • Tejedo, M., H. Duarte, L. M. Gutiérrez-Pesquera, J. F. Beltrán, M. Katzenberger, F. Marangoni, C. A. Navas, A. G. Nicieza, R. A. Relyea, E. L. Rezende, A. Richter-Boix, M. Santos, M. Simon, and M. Solé. 2012. El studio de las tolerancias térmicas para el examen de hipótesis biogeográficas y de la vulnerabilidad de los organismos ante el calentamiento global. Ejemplos en anfibios. Boletín de la Asociación Herpetológica Española 23:1-26.pdf

  • Egea-Serrano, A., R. A. Relyea, M. Tejédo, and M. Torralva. 2012. Understanding the impact of chemicals on amphibians:  A meta-analytic review. Ecology and Evolution 2:1382-1397.pdf

  • Hua, J., and R. A. Relyea. 2012. East Coast versus West Coast: Effects of an insecticide in communities containing different amphibian assemblages. Freshwater Science 21:787-799.pdf

  • Cothran, R. D., K. Chapman, A. R. Stiff, and R. A. Relyea. 2012. "Cryptic" direct benefits of mate choice: Choosy females experience reduced predation risk while in precopula. Behavioral Ecology and Sociobiology 66:905-913.pdf

  • Hammond, J. I., D. K. Jones, P. R. Stephens, and R. A. Relyea. 2012. Phylogeny meets ecotoxicology: Evolutionary patterns in sensitivity to a common insecticide among North American amphibians. Evolutionary Applications 5:593-606.pdf

  • Hoverman, J. T., and R. A. Relyea. 2012. The long-term impacts of predators on prey: Inducible defenses, population dynamics, and indirect effects. Oikos 121:1219-1230.pdf

  • Relyea, R. A. 2012. New effects of Roundup on amphibians:  Predators reduce herbicide mortality while herbicides induce anti-predator morphology. Ecological Applications 22:634-647.  pdf

  • Cothran, R. D., A. R. Stiff, P. D. Jeyasingh, and R. A. Relyea. 2012. Eutrophication and predation risk affect sexual trait expression and mating success. Evolution 66:708-719.  pdf

  • Buck, J. C., E. A. Scheessele, R. A. Relyea, and A. R. Blaustein. 2012. The effects of multiple stressors on wetland communities: pesticides, pathogens, and competing amphibians. Freshwater Biology 57:61-73.  pdf

  • 2011

  • Friedland, A., R. Relyea, and D. Courard-Hauri. 2011 (1st ed.). Environmental Science: Foundations and Applications. Freeman Publishers.  (college textbook)

  • Friedland, A., R. Relyea, and D. Courard-Hauri. 2011 (1st ed.). Environmental Science for AP. Freeman Publishers.  (AP high school textbook)

  • Hoverman, J. T., C. J. Davis, E. E. Werner, D. K. Skelly, R. A. Relyea, and K. L. Yurewicz. 2011. Environmental gradients and the structure of freshwater snail communities. Ecography 34:1049-1058.  pdf

  • Searle, C. L., S. S. Gervasi, J. Hua, J. I. Hammond, R. A. Relyea, D. Olson, and A. R. Blaustein . 2011. Differential host susceptibility to Batrachochytrium dendrobatidis, an emerging amphibian pathogen. Conservation Biology 25:965-974.  pdf

  • Groner, M. L., and R. A. Relyea. 2011. A tale of two pesticides: How common insecticides affect aquatic communities. Freshwater Biology 56:2391-2404.  pdf

  • Cothran, R. D., F. Radarian, and R. A. Relyea. 2011. Altering aquatic food webs with a global insecticide: Arthropod-amphibian links in wetland communities. Journal of the North American Benthological Society 30:893-912.  pdf

  • Auld, J. R., A. A. Agrawal, and R. A. Relyea. 2011. Measuring the cost of plasticity;  A void multi-collinearity. Proceedings of the Royal Society B 278:2726-2727.  pdf

  • Relyea, R. A. 2011. Amphibians are not ready for Roundup®. Pages 267-300 in J. Elliott, C. Bishop, and C. Morrisey, eds. Wildlife Ecotoxicology—Forensic Approaches. Springer.  pdf

  • Stoler, A. B., and R. A. Relyea. 2011. Living in the litter: The influence of tree leaf litter on wetland communities. Oikos 120:862-872.  pdf

  • Blaustein, A. R., B. A. Han, R. A. Relyea, P. T. J. Johnson,  J. C. Buck, S. S. Gervasi, and L. B. Kats. 2011. The complexity of amphibian population declines: Understanding the role of co-factors in driving amphibian losses. Annals of the New York Academy of Sciences 123:108-119.  pdf

  • Jones, D. K., J. R. Hammond, and R. A. Relyea. 2011. Competitive stress can make the herbicide Roundup® more deadly to larval amphibians. Environmental Toxicology and Chemistry 30:446-454.  pdf

  • Auld, J. R., and R. A. Relyea. 2011. Adaptive plasticity in predator-induced defenses in a common freshwater snail: Altered selection and mode of predation due to prey phenotype. Evolutionary Ecology 25:189-202.  pdf

  • 2010

  • Auld, J. R., and R. A. Relyea. 2010. Life-history plasticity and inbreeding depression under mate limitation and predation risk: cumulative lifetime fitness dissected with a life table response experiment. Evolutionary Ecology 24:1171-1185.  pdf

  • Groner, M. L., and R. A. Relyea. 2010. Batrachochytrium dendrobatidis is present in northwest Pennsylvania, USA, with high prevalence in Notophthalmus viridescens. Herpetological Review. 41:462-465.  pdf

  • Relyea, R. A., and K. Edwards. 2010. What doesn’t kill you makes you sluggish:  How sublethal pesticides alter predator-prey interactions.  Copeia 2010:558-567.  pdf

  • Cothran, R. D., A. Kuzmic, G. A. Wellborn, and R. A. Relyea. 2010. Phenotypic manipulation provides insights into the function of a sexually selected trait in a freshwater crustacean species complex. Animal Behaviour 80:543-549.  pdf

  • Jones, D. K., J. I. Hammond, and R. A. Relyea. 2010. Roundup® and amphibians:  The importance of concentration, application time, and stratification. Environmental Toxicology and Chemistry 29:2016-2025.  pdf

  • Auld, J. R., A. A. Agrawal, and R.A. Relyea. 2010. Re-evaluating the costs and limits of adaptive phenotypic plasticity. Proceedings of the Royal Society B 277:503-511.  pdf

  • Auld, J.R., and R. A. Relyea. 2010. Inbreeding depression in adaptive plasticity under predation risk in a freshwater snail. Biology Letters 6:222-224.  pdf

  • Cothran, R., R. Greco, and R. A. Relyea. 2010. No evidence that a common pesticide impairs female mate choice in a freshwater amphipod. Environmental Toxicology 25:310-314.  pdf

  • Relyea, R. A. 2010. Multiple stressors and indirect food web effects of contaminants on herptofauna.  Pages 475-486 in D. Sparling, ed. Ecotoxicology of Amphibians and Reptiles, 2nd edition.  pdf

  • Click here for a complete list of publications

E-mail Lab