Skip to main content
Sign In

University of Colorado Denver College of Liberal Arts and Sciences

Biology Logo

Faculty & Staff Directory

Greg Cronin, Ph.D.

Dr. Greg Cronin

Associate Professor

Office Location: SI 4100
Phone: (303) 556-6036
Fax: (303) 556-4352
​Dr. Cronin is on Sabbatical 
until August 2015
Areas of Expertise:
Applied Aquatic Ecology, Aquaponics


Education & Degrees 

Ph.D., Marine Sciences, University of North Carolina at Chapel Hill, 1994

B.A., Biochemistry and Chemistry, University of Kansas, 1989


Dr. Cronin uses a transdisciplinary approach to restore and protect ecosystems.  He is a fan of using the STEAM disciplines (Science, Technology, Engineering, Arts, and Math) to promote a sustainable society and protection of Earth’s ecosystems.  Two main foci of this schoalrship is using aquaponics to sustainably produce food, and restoring watersheds in Haiti.  


Urban communities import nearly 100% of their food from an average distance of 1,500 – 2,500 miles. Additionally, low-income urban neighborhoods are often located 10 miles from a grocery store, leaving residents without access to healthy food. Aquaponics is a technology that uses engineered aquatic ecosystems to produce fresh fish and vegetables year-round. With aquaponics, edible plants are both the primary producers and water purifiers, while the fish provide fertilizer for the plants (and food for people). Such technology can be done at a neighborhood scale, offering sustainable, healthy fresh food to underserved people, without the use of artificial fertilizer and pesticides that currently pollute our waterways. Aquaponics markets also create jobs in the communities they serve. With over 1 billion undernourished people on the planet, there is a great need for sustainable agriculture across the globe.


Haiti has the most degraded ecosystems in the western hemisphere.  Dr. Cronin works with Haitians to restore watersheds, taking a systems appraoch of restoring from ridge to reef.  This includes revegetating the landscape, restoring fertility via soil building, and producing food in a sustainable manner.


Dr. Cronin is active with numerous groups to help make the campus more sustainable through education and community building. He initiated an effort to create a community garden on Auraria campus, which is moving forward with strong support from students, staff, and faculty. He and his students organize fairs and concerts to educate people about sustainability and to motivate them to adopt sustainable behaviors. Dr. Cronin serves on the Auraria Campus Sustainability Advisory Council and the UCD Chancellor's Task Force for Sustainability.


Select Publications  

Cronin, G. 2014. Transdisciplinary scholarship: Integrating Boyer’s Model of Scholarship with Transdisciplinary Research. Transdisciplinary Journal of Engineering & Science. (in press)

Sawyer, J.D., Manci, B., Ground, T., Cronin, G. Hull, J., Webb, T., Brashears, B. 2012.  Aquaponics feasibility study for the Denver County Sheriff’s Department. 80 pp.

Cronin, G. 2011. Aquaponics. Encyclopedia of Environmental Issues. Salem Press, Pasadena.

Pattison, A and Auraria Campus Sustainability Council. 2010. The Auraria Campus Climate Action Plan. AHEC, Denver.​

Cronin, G., J. H. McCutchan, J. Pitlick, and W.M. Lewis, Jr. 2007. "Use of Shields stress to reconstruct and forecast changes in river metabolism." Freshwater Biology 52: 1587-1601.


Schlacher T. and G. Cronin. 2007. "A trophic cascade in a macrophyte-based food web at the land–water ecotone." Ecological Research 22: 749-755.


Cronin, G., W.M. Lewis, Jr., and MA Scheisher. 2006. "Influence of freshwater macrophytes on the littoral ecosystem structure and function of a young Colorado reservoir." Aquatic Botany 85: 37-43.


Stearns, M., J. A. Tindall, G. Cronin, M. J. Friedel and E. Berquist. 2005. "Effects of Coal-Bed Methane Discharge Waters on the Vegetation and Soil Ecosystem in Powder River Basin, Wyoming," Water, Air, & Soil Pollution 168: 33-57.


Cronin G, and D. M. Lodge. 2003. "Effects of light and nutrient availability on the growth, allocation, carbon/nutrient balance, phenolic chemistry, and resistance to herbivory of two freshwater macrophytes." Oecologia 137: 32-41.


Cronin, G. 2001. "Resource allocation in seaweeds and marine invertebrates: Chemical defense patterns in relation to defense theories." In: J.B McClintock and B.J. Baker (eds.) Marine Chemical Ecology. CRC Press. 325-353.

Smith, L.K., W.M. Lewis, Jr., J.P. Chanton, G. Cronin, and S.K. Hamilton. 2000.  Methane emissions from the Orinoco River Floodplain, Venezuela. Biogeochemistry 51: 113-140.

Cronin, G, K. D. Wissing*, and D. M. Lodge. 1998.  Comparative feeding selectivity of herbivorous insects on water lilies: Aquatic vs. semi-terrestrial insects and submersed vs. floating leaves. Freshwater Biology 39: 243-257

Cronin, G., V. J. Paul, M. E. Hay, and W. Fenical. 1997.  Feeding deterrent effects of new diterpenes from Dictyota acutiloba: Geographic variation in herbivore resistance to seaweed defenses. J. Chemical Ecology 23: 289-302.

Cronin, G. 1997. Native Insect is Purple Loosestrife Biocontrol Candidate. Restoration and Management Notes. Summer 1997.

Cronin, G. and M. E. Hay. 1996. Seaweed-herbivore interactions depend on recent history of both the plant and animal. Ecology 77: 1531-1543.

Cronin, G. and M. E. Hay. 1996.  Induction of seaweed chemical defenses by amphipod grazing. Ecology 77:2287-2301.

Cronin, G. and M. E. Hay. 1996.  Within-plant variation in seaweed palatability and chemical defenses: Optimal defense theory versus the growth-differentiation balance hypothesis. Oecologia 105: 361-368.

Cronin, G. and M. E. Hay. 1996.  Chemical defenses, protein content, and susceptibility to herbivory of diploid vs. haploid stages of the isomorphic brown alga Dictyota ciliolata (Phaeophyta). Botanica Marina 39: 395-399.

Cronin, G. and M. E. Hay. 1996.  Effects of light and nutrient availability on the growth, secondary chemistry, and resistance to herbivory of two brown seaweeds. Oikos 77:93-106.

Hardt, I., W. Fenical, G. Cronin, and M. E. Hay.  1996. New feeding deterrents from the tropical brown alga Dictyota acutiloba. Phytochemistry 43: 71-73.

Howard, J. J., M. L. Henneman, G. Cronin, J. A. Fox, and G. Hormiga. 1996. Conditioning of scouts and recruits during foraging by a leafcutting ant (Atta columbica). Animal Behaviour 52: 299-306.

Cronin, G, M. E. Hay, W. Fenical, and N. Lindquist. 1995. Distribution, density, and sequestration of host chemical defenses by the specialist nudibranch Tritonia hamnerorum found at high densities on the sea fan Gorgonia ventalina. Marine Ecology Progress Series 119:177-189

Cronin, G, N. Lindquist, M. E. Hay, and W. Fenical. 1995.  Effects of storage and extraction procedures on yields of lipophilic metabolites from the brown seaweeds Dictyota ciliolata and D. menstrualis. Marine Ecology Progress Series 119:265-2​

Courses Taught 

BIOL 3412: Fundamentals of Applied Ecology
BIOL 4416/5416: Aquatic Ecology
BIOL 4050: Marine Biology
BIOL 5445: Applied Environmental Biology
SUST 3010: Sustainability I: The Non-sustainable Past