Jessica Rettig

Jessica E. Rettig

Professor of Biology
Director of Global Health
Coordinator, Anderson Science Program
Coordinator, Ronneberg Lecture Series
Position Type
- Present
Aquatic Ecology
She / Her

Dr. Rettig has been teaching at Denison since the fall of 2000 and currently is a full professor in the Biology Department and the Director of the Global Health Program. Dr. Rettig teaches introductory and advanced courses in biology, Introduction to Global Health, and she’s taught in Denison’s Writing Program. Dr. Rettig’s graduate training centered on ecology and evolutionary biology and she earned her Ph.D. from Michigan State University, completing much of her research at MSU’s Kellogg Biological Station. In addition to teaching and her research in aquatic ecology, Dr. Rettig serves as the coordinator of Denison’s Anderson Science Program where she is responsible for organizing and supporting an undergraduate summer research experience program for 60-70 students annually. She also directs Denison’s S-STEM Program which uses a grant from the National Science Foundation to support mentoring pathways for students in the sciences. External to Denison, Dr. Rettig serves as a Peer Reviewer for colleges and universities undergoing accreditation reviews with the Higher Learning Commission.

Ph.D. Michigan State University in Zoology and in Ecology, Evolutionary Biology, & Behavior (EEBB); B.A. Earlham College in Biology with Departmental and College Honors

Learning & Teaching

  • Introduction to Global Health (GH 100)
  • Vertebrate Zoology (BIOL 313)
  • Population and Community Ecology (BIOL 375)
  • Ecology & Evolution (BIOL 230)
  • Advising Circle 101 (AC-101)
  • Writing Workshop 101: Science, Society, & Infectious Disease (W-101)
  • Introduction to the Science of Biology (BIOL 150)
  • Invertebrate Zoology (BIOL 324)
  • General Zoology (BIOL 102)
Academic Positions
  • 2023-present Director of the Global Health Program, Denison University
  • 2019-present Professor of Biology, Denison University
  • 2007-present Anderson Science Program Coordinator
  • 2010-2013 Chair of Biology, Denison University
  • 2006-2019 Associate Professor of Biology, Denison University
  • 2000-2006 Assistant Professor of Biology, Denison University
  • 1999-2000 Assistant Professor of Biology, William Jewell College
  • 1997-1999 Instructor of Biology, William Jewell College
  • 1996-1997 Visiting Assistant Professor of Biology, Earlham College


I study the ecology of animal populations inhabiting in small ponds (< 2 ha). My study organisms include native sunfish, non-native mosquitofish, their macroinvertebrate and zooplankton prey, and other animals (i.e., crayfish, amphibians, turtles).

My main focus as a scholar has been on the ecology of behavioral, trophic, and competitive interactions that occur in small ponds (< 2 ha). I use native sunfish, non-native mosquitofish, their macroinvertebrate and zooplankton prey, and other potential interactors (i.e., crayfish or amphibians) as study organisms. Zooplankton are tiny crustaceans and insects that serve as prey for many fish. My overall goals are to better understand basic questions about pond ecology and species interactions: Why are certain species present or absent in the pond (what factors contribute to their presence or absence)? How do particular species living in a pond interact with each other?

My research projects utilize field studies of the ecology of animals living in small ponds, as well as lab and mesocosm experiments. Recent research falls into three major arenas: Interactions between native and non-native fish & the impacts of fish on aquatic communities; Zooplankton Communities & Pond Ecology (often in collaboration with Dr. Smith [Denison University]); Pond Turtle Ecology (in collaboration with Dr. Smith and Dr. Iverson [Earlham College]).

I routinely work with undergraduates on research, hosting students in the lab during the summer and mentoring senior biology majors through their Senior Research projects (N=24; BIOL 451-452).



Recent Peer-reviewed Publications (*=undergraduate co-author)

  • Rettig, J.E., M. Surace*, K.D. Rose*, A.J. Baird*, Z.D. Baker*, and G.R. Smith. 2023. Variation in the diets of western mosquitofish (Gambusia affinis) in two ponds: effects of time and coexistence with centrarchid fishes. Animal Biology 73: 407-421.
  • Iverson, J.B., G.R. Smith, and J.E. Rettig. 2022. Chrysemy picta reproductive output. Herpetological Review 53(1): 115-116.
  • Smith, G.R., J.B. Iverson, and J.E. Rettig. 2022. Do observed sex ratios in a turtle community in northern Indiana vary from 1979-2014? Amphibian & Reptile Conservation 16(1):193-202.
  • Iverson, J.B., G.R. Smith, and J.E. Rettig. 2022. Growth in Common Snapping Turtles, Chelydra serpentina (Testundines: Chelydridae), in northern Indiana. Herpetology Notes 15: 41-43.
  • Smith, W.O.*, J.E. Rettig, L.E. Smith*, and G.R. Smith. 2021. Prevalence of leeches and algae on Painted Turtles (Chrysemys picta) in four created ponds in central Ohio: Effects of pond, sex, size, and month. Chelonian Conservation and Biology 20(2): 304-307.
  • Rettig, J.E., N.R. Teeters*, and G.R. Smith. 2021. Effects of Bluegill and two species of tadpoles on experimental zooplankton communities. American Midland Naturalist 186:95-105.
  • Smith, G.R., and J.E. Rettig. 2021. Influence of the presence of invasive mosquitofish and submerged vegetation on oviposition site selection by gray treefrogs (Hyla versicolor). Herpetological Journal 31:85-90.
  • Rettig, J.E., and G.R. Smith. 2021. Relative strength of top-down effects of an invasive fish and bottom-up effects of nutrient addition in a simple aquatic food web. Environmental Science and Pollution Research 28: 5845-5853.
  • Smith, G.R., J.E. Rettig, and J.B. Iverson. 2020. Frequency of and temporal trends in shell anomalies in a turtle community in a northern Indiana lake. Chelonian Conservation and Biology 19(2) 277-282. doi:10.2744/CCB-1408.1
  • Iverson, J.B., G.R. Smith, and J.E. Rettig. 2019. Body size and growth in Northern Map Turtles (Graptemys geographica) in Indiana. Journal of Herpetology 53: 297-301.
  • Smith, G.R., J.E. Rettig, M. Smyk*, M. Jones*, G. Eng-Surowiec*, D. Mirshavili*, and J. Hollis*. 2019. Consumption of the eggs, hatchlings, and tadpoles of Green Frogs (Lithobates clamitans) by native and non-native predators. Amphibia-Reptilia 40: 383-387.
  • *Clemmer, J.H. and J.E. Rettig. 2019. Native bluegill influence the foraging and aggressive behavior of invasive mosquitofish PeerJ:e6203

Recent Conference Presentations (*=undergraduate co-author)

  • Rettig, J.E., J.E. Katz, R. Mitton-Fry, S.M. Villarreal, K.M. Specht, S.A. Stasko, and B.I. Wharton. 2022. Multilevel mentoring to improve belonging, metacognition, and science identity of bachelor degree-seeking science and mathematics students. American Association for the Advancement of Science – S-STEM Conference, Washington, D.C.
  • Rettig, J.E. 2021. A multi-year assessment of zooplankton community assembly in a newly constructed permanent pond. Annual Meeting of the Ecological Society of America. Conducted virtually August 2-6, 2021.
  • Rettig, J.E., C.K. Hoy*, and J.V. Scheff*. 2020. Temporal patterns of macroinvertebrate abundance in a small constructed pond suggest an impact of predation by sunfish. Annual Meeting of the Society for Freshwater Sciences. Conducted virtually in June 2020.
  • Rettig, J.E. 2018. Invasion by a native species: Consequences for population dynamics and diet of a non-native species. Annual Meeting of the Society for Freshwater Sciences. Detroit, MI.
  • *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.


Professional Memberships
  • Ecological Society of America
  • American Society of Ichthyologists and Herpetologists
  • American Society of Limnology and Oceanography
  • American Fisheries Society
  • Association for Women in Science
  • Phi Beta Kappa
  • Sigma Xi
  • Society for Freshwater Science
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


Grants & Funding

External Grants

  • 2021 Multilevel mentoring to improve belonging, metacognition, and science identity of bachelor degree-seeking science and mathematics students. S-STEM grant from the National Science Foundation. Funded for $650,000 over 5 years with >60% of grant used for undergraduate scholarships. Principle Investigator (PI).
  • 2002 Stressor effects on amphibian larval communities: Integrated Experiments on the effects of nitrate. Declining Amphibian Populations Task Force Seed Grant. Funded for $1710. (co-PI with Dr. Smith).
Honors & Awards
  • 2010–2015 Henry Chisholm Endowed Chair in the Natural Sciences (Denison)
  • 2006 Commitment to Community Award, Denison Chapter of Mortar Board
Student Collaborations

Senior Research Projects from Dr. Rettig’s lab since 2015

  • Davit Mirzashvili (‘15) - Investigating and quantifying predator and prey behavior of mosquitofish, crayfish, and gray tree tadpoles
  • Genevieve Eng-Surowiec (‘15) - Examining Prey Preferences for Baby Mosquitofish Under Different Competitive Situations
  • Sneha Vissa (‘15) - An analysis of temperature, salinity, chlorophyll-a, nutrient concentrations and zooplankton diversity in the equatorial South Pacific Ocean, including the Phoenix Islands Protected Area (PIPA, Republic of Kiribati)
  • Kyle Rose (‘16) - Examining the effects of an introduced sunfish species on an established mosquitofish population in two Ohio ponds: population size and diets
  • Archit Agarwal (‘17) - Student Involvement in a Small Liberal Arts College: How Does Social Engagement Relate to Indicators of Stress & Success?
  • Andrew Baird (‘17) Comparison of population size and diets of coexisting mosquitofish and sunfish in a small Ohio pond – 2015 & 2016
  • Kenny Connelly (‘20) - Trends in richness and diversity of macroinvertebrates in a small Ohio pond
  • Claire Hoy (‘20) - Temporal pattern of macroinvertebrate abundance and possible predatory effects in a constructed pond in Ohio
  • Maggie O’Neill-Dee (‘20) - Seasonal patterns of zooplankton & algae abundance in a small Ohio pond across four years
  • Jerod Scheff (‘20) - Survey of vertebrate life in four small Ohio ponds
  • Chris Negrete (‘21) - A Comparison of Fish Communities Current and Past in Ebaugh Pond and Olde Minnow Pond
  • Paneri Patel (‘22) – Multivariate exploration and comparison of zooplankton communities in two small ponds
  • Henry Brooks (‘22) – Survey of fish communities and dietary analysis of fish in a small Ohio pond.


Back to top