1. Bioassay of Two Ponds Katie Kraska Stephen Hesterberg Matt Brown

2. Motivations for Research Dramatic shifts in free nutrient levels Eutrophication Effects specific to our area Research often done on the Quarry Pond

3. Goals and Hypotheses Determine limiting nutrients in two different systems Environment Landscape positioning Different levels of human disturbance 1. The Woodland Pond would be P limited, N limited, or both 2. The Golf Course Pond on would not be limited by either P or N because of artificially introduced chemicals and nutrients

4. Methods: Study Sites Woodland Pond Pond at Old Hickory Golf Course Average depth: 2.1 m, pH 7.5, N:P ratio 45:1 Leech et al. SRF Summer Research

5. Methods: Experimental Design Filtered 500 mL through an 11- micron mesh 3 replicates per treatment 500 µL of nutrients added 5 days

6. Methods Continued… 50 mL sampled and filtered GF/F filters placed in 10 mL acetone for 12 hrs Fluorometer used to measure chlorophyll in ug/L Kruskal-Wallis

7. p = 0.08, no significance

8. p = 0.10, no significance

9. Discussion Woodland Pond: – Variation? – Nitrogen – Zooplankton – Clumping of algae – Light

10. Golf Course Pond: Decrease? – Protists – Zooplankton – Clumping of algae – Light – Too many nutrients?

11. Further Research Maximum production rate Seasonal Variation Controlled experimentation on mixotrophic protists Specific species present in each

12. References On the Strategy of "Eating Your Competitor": A Mathematical Analysis of Algal MixotrophyT. Frede Thingstad, Harry Havskum, Kristine Garde and Bo RiemannEcology, Vol. 77, No. 7 (Oct., 1996), pp. 2108-2118 Rossignol, Karen L., Hans W. Paerl, John M. Fear, and Jeremy S. Braddy. "Nutrients in Precipitation and the Phytoplankton Responses to Enrichment in Surface Waters of the Albemarle Peninsula, NC, USA after the Establishment of a Large-scale Chicken Egg Farm." Hydrobiologia (2010): 181-91. Print. Hitchman, Richard B., and Harriet L. Jones. "The Role of Mixotrophic Protists in the Population Dynamics of the Microbial Food Web in a Small Artificial Pond." Freshwater Biology 43.2 (2000): 231-41. Print. Koh, Kyungjoon, Greg E. Bell, and Justin Moss. "Nutrient Runoff during Natural Rainfall Event from Golf Course Fairways." Horticulture and Landscape Architecture: Oklahoma State University (2007). Print.