Education

B.S. Chemistry, Northern Illinois University, 2004

Research Interests

I am interested in the role organic nitrogen plays in harmful algal bloom dynamics. In the past, most studies of nitrogen utilization by phytoplankton have examined the dissolved inorganic species (nitrate and ammonium) since the dissolved organics such as urea, amino acids, and humics were thought to be refractory. Recent research has determined this paradigm false; dissolved organic nitrogen (DON) can be labile, to varying degrees, and likely plays a role in phytoplankton nutrition. My project examines uptake of DON by harmful phytoplankton using 15N labeled tracers. I am evaluating how DON uptake may differ between strains of the same harmful phytoplankton species as well as variations depending on the physiological state of the cell. The project also explores various mechanisms harmful phytoplankton utilize to facilitate nutrient uptake. These may include proteolytic enzymes and/ or pinocytosis. Finally, I plan to investigate competition for resources between harmful and benign phytoplankton.

Field and Research Experience

• Graduate Research Assistant, Virginia Institute of Marine Science, Gloucester Point, VA. Advisor: Dr. Deborah Bronk, 2004-Present

• R/V Point Sur, Santa Barbara Channel, April 14-23, 2006

• Florida Fish and Wildlife Institute, St. Petersburg, FL. February 21-24, 2006

• 15N uptake experiments on cultured Karenia brevis isolates

• R/V Cape Henlopen, Chesapeake Bay tributaries, August 11-15, 2005

• R/V Pelican, Gulf of Mexico-Mississippi River plume, July 12-20, 2005

• R/V Cape Henlopen, Chesapeake Bay, April 8-14, 2005

• NSF REU Fellow, Great Lakes WATER Institute, Milwaukee, WI. June-August 2003, Mentor: Dr. Russell Cuhel. Studied the characterization and variability of reduced sulfur content in hydrothermal vent waters in Yellowstone Lake, WY.

• Undergraduate Research Assistant, Biology Department, Northern Illinois

• University, DeKalb, IL. January 2003-May 2004, Mentor: Dr. Gabriel Holbrook. Investigated the effects of light/dark transitions on rubisco activity in soybean plants.

Publications

• Bronk, D.A., See J.H., Bradley, P., Killberg, L. (2006) DON as a source of bioavailable nitrogen for phytoplankton. Biogeosciences Discussions. (submitted)

Oral Presentations

• "Inorganic and organic nitrogen uptake kinetics in field populations of dinoflagellates from five Chesapeake Bay tributaries, USA." L.M. Killberg and D.A. Bronk. ASLO Summer Meeting, Victoria, British Columbia, June 4-9, 2006

• "A general overview of harmful algal blooms." L.M. Killberg. Presented at the Environmental Chemistry workshop, VIMS, Gloucester Point, VA, May 25, 2006

Poster Presentations

• "Characterization and variability of reduced sulfur content in Yellowstone Lake, WY, hydrothermal vent waters." L. Killberg and R.L. Cuhel. Great Lakes WATER Institute REU Final Poster Presentation, Milwaukee, WI, August 2003

• "Photosynthesis in soybean plants: Effect of light/ dark transitions on rubisco activity." L.M. Killberg and G.P. Holbrook. Northern Illinois University Department of Biological Sciences Research Symposium, DeKalb, IL, April 2003

Teaching Experience

• Teaching Assistant: Coastal and Estuarine Processes and Issues. Virginia Institute of Marine Science, January-May 2006

Professional Memberships

• American Society of Limnology and Oceanography