Research Interests:

Stable isotope ecology and the influence of light attenuation on estuarine and coastal ecosystem dynamics.

Projects

1) Field study on the natural controls of photosynthetic carbon fractionation in marine microalgae, with particular focus on light attenuation.

2) d13C and d15N isotope maps or “isoscapes” of common fish populations and primary producers on the West Florida Shelf. These isoscapes enable the determination of fish site fidelity and the dominant trophic base that supports fish biomass.

3) Seasonal changes in water quality in the Caloosahatchee River. Controlled fresh water releases from Lake Okeechobee result in a dynamic downstream habitat for fish and zooplankton, with patchy areas of phytoplankton sedimentation and hypoxia.

Publications

Bultman, T.L., Rodstrom, J.L., Radabaugh, K.R., VanDop, J.D., Librizzi, J.M., Longwell L.L., Pulas C., Grant L., and Sullivan, T. J. 2009. Influence of genetic variation in fungal endophyte of a grass on an herbivore and its parasitoid. Entomologia Experimentalis et Applicata 130: 173-180.

Radabaugh, K.R and Peebles, E.B. Detection and classification of phytoplankton deposits along an estuarine gradient (submitted to Marine Ecology Progress Series)

Radabaugh, K.R., Malkin, E.M., Hollander, D.J., and Peebles, E.B. Light-environment effects on in-situ carbon isotope fractionation by aquatic microalgae; Relevance to trophic analyses. (in prep)

Presentations

Radabaugh K.R., Huelster, S.A., Hollander, D.J. and Peebles, E.B. (2011) Variation in Fish d13C and d15N along a Climatic Gradient: Implications for site fidelity and selective trophic pathway effects. USF College of Marine Science Graduate Student Symposium. Oral Presentation. Tied 1st place for Best Student Presentation.

Radabaugh K.R., Huelster, S.A., Hollander, D.J. and Peebles, E.B. (2011) Variation in Fish d13C and d15N along a Climatic Gradient: Implications for site fidelity and selective trophic pathway effects. Southern Division of the American Fisheries Society Spring Meeting. Oral Presentation

Radabaugh K.R., Huelster, S.A., Hollander, D.J. and Peebles, E.B. (2010) Variation in Fish d13C and d15N along a Climatic Gradient: An Isoscape Perspective for the West Florida Shelf. AGU Fall Meeting. Poster Presentation

Radabaugh, K.R., Malkin, E.M., Wolfgang, K.J., Hollander, D.J., and Peebles, E.B (2009) Rainy season controls on water chemistry, algal growth rates, and photosynthetic carbon isotope fractionation in Bayboro Harbor. USF College of Marine Science Graduate Student Symposium. Oral Presentation.

Radabaugh, K.R., Ellis, G.S. and Peebles, E.B. (2008) Integrated pelagic and benthic responses to managed freshwater diversions into the Caloosahatchee River estuary: Early results from a new multi-sensor platform. USF Research One Poster Symposium and Competition. Poster presentation.

Research Cruise and Field Experience

West Florida shelf, Gulf of Mexico (October 2010)
12-day otter trawling cruise on the R/V Tommy Munro with the Florida Fish and Wildlife Research Institute for the annual Southeast Area Monitoring and Assessment Program (SEAMAP) survey

West Florida shelf, Gulf of Mexico (June-July 2010)
11-day otter trawling cruise on the R/V Tommy Munro with the Florida Fish and Wildlife Research Institute for the annual SEAMAP survey

West Florida shelf, Gulf of Mexico (May 2010)
7-day research cruise on the R/V Weatherbird to the Deepwater Horizon oil spill. Collected various water samples, optic measurements, and performed trawls to establish baseline fish populations in preimpacted areas. Principal investigator: David Jones

Brazilian continental shelf (February-March 2010)
21-day paleoclimatology cruise on the R/V Knorr to core sediment in the outflow of the Amazon River. Principal investigators: David Hollander of USF and Paul Baker of Duke University

Florida Keys (April 2009)
3-day sea-floor mapping cruise on the R/V Weatherbird off Key West, Florida. Principal Investigator: David Naar

Fort Myers, Florida (May 2008-May 2010)
2-year project involving monthly sampling trips to the Caloosahatchee River to monitor water quality and zooplankton distribution. Principal Investigator: Ernst Peebles