Jessica E. Rettig

Jessica E. Rettig

Associate Professor of Biology; Anderson Endowment Director
Position Type 
2000 - Present
All Affiliations 
Aquatic Ecology



I am an aquatic ecologist, which means that I study the organisms that live in ponds and akes, and how these organisms interact with each other and their environment. Basically, I am a big fan of learning about the animals and plants that live in the water and as an ecologist I want to know about biological interactions such as predation and competition. Students in my research group assist with sampling ponds, collecting fish, or running experiments to learn more about the basic biology and ecology of animals like fish, zooplankton, or amphibians. Advanced students design and conduct their own research projects during the summer or academic year. I enjoy doing science – for me this means getting to design a project, collect data and analyze data, often in the great outdoors. I bring this enthusiasm for doing science to my classes where students engage in research projects, from the design stage through reporting the results, in order to le arn more about the natural world.

As a scientist I also recognize the importance of communicating scientific ideas and concepts, thus all my courses provide opportunities for students to hone their skills in oral and written communication. Indeed, Population & Community Ecology serves as a writing intensive class in Denison’s General Education curriculum, and Vertebrate Zoology serves as an oral communication course. Given my interest in communication, I recently began teaching in Denison’s Writing Program by teaching a Writing Workshop (W-101) for first year students. This course, titled Science, Society, and Infectious Disease, uses issues in infectious disease as the topical focus to teach students how to write informed, evidence-based argumentative papers at the college-level. If you are interested in doing science, or in communicating science, please contact me via email.

B.A., Earlham College; Ph.D., Michigan State University

Learning & Teaching

  • Ecology & Evolution (BIOL 230)
  • Vertebrate Zoology (BIOL 313)
  • Population & Community Ecology (BIOL 375)
  • Writing Workshop: Science, Society, & Infectious Disease (W-101)
  • Advising Circle (AC-101); Advising Seminar (AS-101); First Year Seminar (FSY 103)
Academic Positions 
  • Academic Positions Associate Professor, Department of Biology at Denison University, 2006 - present
  • Assistant Professor, Department of Biology at Denison University, 2000 - 2006
  • Assistant Professor, Biology Department at William Jewell College, Liberty, MO, 1997 - 2000
  • Visiting Assistant Professor, Biology Department at Earlham College, Richmond, IN, 1996 - 1997


Population & community ecology; aquatic ecology — I study the ecology of ponds and the organisms that live in ponds. On a broad scale I am interested in examining the interactions between fish, invertebrate, and plants and I also study community dynamics within small ponds. Often I compare ponds to each other or I study a single a pond across time (several years). I examine competitive and predation-linked interactions between different species of fishes, such as native bluegill and non-native mosquitofish and I explore the short- and long-term relationship between fish and their zooplankton prey (tiny crustaceans). I use a mixture of field surveys, mesocosm experiments, and lab experiments to address different research questions.

Recent lines of research include a mesocosm experiment and a multi-summer field-survey project to explore interactions between native sunfish and non-native mosquitofish. For the mesocosm experiment, I manipulated the abundance of bluegill sunfish and mosquitofish in cattletanks at the Denison BioReserve to quantify how these fishes affected the prey community and how competition between the two species influenced the growth of the fish. This mesocosm experiment was conducted in collaboration with a research student and was presented at the annual meeting of the Ecological Society of America in August 2016. For the field-survey project (2015-2017) I was assisted by several students to track the abundance of mosquitofish and longear sunfish in Olde Minnow and Wood Duck ponds at the BioReserve. Based on the mesocosm experiment with bluegill (a close relative of the longear), I suspected that the the longear and mosquitofish might compete for prey it ems, so we also collected fish of each species to track their diets (stomach composition) across the summer during 2015 and 2016.


  • Geyer, R.L.*, G.R. Smith, and J.E. Rettig. 2016. Effects of Roundup formulations, nutrient addition, and Western Mosquitofish (Gambusia affinis) on aquatic communities. Environmental Science and Pollution Research. 23:11729-11739.
  • Smith, G.R., A.A. Burgett*, and J.E. Rettig. 2012. Effects of the anuran tadpole assemblage and nutrient enrichment on freshwater snail abundance (Physella sp.). American Midland Naturalist 168: 341-351.
  • *Buttermore, K.F., P.N. Litkenhaus*, D.C. Torpey*, G.R. Smith, and J.E. Rettig. 2011. Effects of mosquitofish (Gambusia affinis) cues on wood frog (Lithobates sylvaticus) tadpole activity. Acta Herpetologica 6: 81-85.
  • Rettig, J.E., and G.R. Smith. 2009. Class research projects in ecology courses: Methods to un-“can” the experience. Journal of College Science Teaching 38(5): 38-42.
  • *Arrington, J.J., K.R.J. Thaman*, J.E. Rettig, and G.R. Smith. 2009. Feeding harassment among male and female mosquitofish (Gambusia affinis). Journal of Freshwater Ecology 24: 327-329.
  • *Russo, G., A. Chou*, J.E. Rettig, and G.R. Smith. 2008. Foraging responses of mosquitofish (Gambusia affinis) to items of different sizes and colors. Journal of Freshwater Ecology 23: 677-678.
  • Rettig, J.E, L.S. Schuman*, and J.K. McCloskey*. 2006. Seasonal patterns of abundance: do zooplankton in small ponds do the same thing every spring-summer? Hydrobiologia. 556: 193-207.
  • Smith, G.R., J.B. Iverson, and J.E. Rettig. 2006. Changes in a turtle community from a northern Indiana lake: a long-term study. Journal of Herpetology 40: 180-185.
  • Garvey, J.E., J.E. Rettig, R.A. Stein, D.M. Lodge, and S.P. Klosiewski. 2003. Scale-dependent associations among fish predation, littoral habitat, and distributions of crayfish species. Ecology 84: 3339-3348.
  • Rettig, J.E. 2003. Zooplankton responses to predation by larval bluegill: an enclosure experiment. Freshwater Biology 48: 636-648.
  • Rettig, J.E. and G.G. Mittelbach. 2002. Interactions between adult and larval bluegill sunfish: positive and negative effects. Oecologia 130: 222-230.
  • Smith, G.R., J.E. Rettig, A.M. Frahm, and P.W. Gabrielson. 2000. Prediction Generation and Testing: An Exercise Using Plant Distributions. Bioscene: Journal of College Biology Teaching 26(3): 19-21.
  • Smith, G.R., J. E. Rettig, G.G. Mittelbach, J.L. Valiulis*, and S.R. Schaack*. 1999. The effects of fish on assemblages of amphibians in ponds: a field experiment. Freshwater Biology 41: 829-837.
  • Rettig, J.E. 1998. Variation in species composition of larval assemblages: using electrophoresis to identify larval sunfish. Transactions of the American Fisheries Society 127: 661-668.
  • Rettig, J.E., R.C. Fuller, A.L. Corbett, and T. Getty. 1997. Fluctuating asymmetry indicates levels of competition in an even-aged poplar clone. Oikos 80: 123-127.
  • Mittelbach, G.G., A.M. Turner, D.J. Hall, J.E. Rettig, and C.W. Osenberg. 1995. Perturbation and resilience: a long-term, whole-lake study of predator extinction and reintroduction. Ecology 76: 2347-2360.
  • *Tristano, E.P. and J.E. Rettig. 2016 Interactions between native and non-native fishes and their impact on zooplankton in small temperate ponds. Annual Meeting of the Ecological Society of America. Ft. Lauderdale, FL.
  • Reding, J.A., G.R. Smith, J.E. Rettig, R.N. Homan, D.J. Spieles, T.D. Schultz, A.C. McCall, and B. Sodergren. 2016. The Granville Schools Land Lab: A K-12/college/government teaching a research collaboration. Annual Meeting of the Ecological Society of America. Ft. Lauderdale, FL.
  • *Burger, A.C., G.R. Smith, and J.E. Rettig. 2011. Competition between invasive mosquitofish and native bluegill sunfish. Annual Meeting of the Ecological Society of America. Austin, TX.
  • *Miller, E.Z. and J.E. Rettig. 2011. Behavior in groups: measuring aggression between bluegill (Lepomis macrochirus) and invasive mosquitofish (Gambusia affinis). Annual Meeting of the Ecological Society of America. Austin, TX.
  • Rettig, J.E. and J.H. Clemmer*. 2011. An experimental analysis of foraging and aggressive behavior between mosquitofish and bluegill. Annual Meeting of the Ecological Society of America. Austin, TX.


Professional Memberships 
  • American Fisheries Society
  • American Society of Ichthyologists and Herpetologists
  • American Society of Limnology and Oceanography
  • Association for Women in Science
  • Ecological Society of America
  • The Ohio Academy of Science
  • Sigma Xi
Professional Service (includes Denison Service) 
  • Peer-Reviewer for the Higher Learning Commission's Open Pathway 2015-present
  • System Appraiser for the Higher Learning Commission’s Academic Quality Improvement Program (AQIP) 2010-2013

Service to Denison

  • Chair- Biology Department 2010-2013
  • Anderson Endowment Director 2007-present
  • Ronneberg Lecture Series Coordinator 2007-present


Honors & Awards 

Grants, Fellowships and Honors

  • Henry Chisholm Endowed Chair in the Natural Sciences (2010-2015)
  • Commitment to Community Award, Denison Chapter of Mortar Board (2006)
  • Phi Beta Kappa (1991, Earlham College)