Bioassay of Two Ponds

Katie KraskaStephen Hesterberg 

Matt Brown 

Motivations for Research

• Dramatic shifts in free nutrient levels 

• Eutrophication

• Effects specific to our area

• Research often done on the Quarry Pond         

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

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

Methods: Experimental Design 

• Filtered 500 mL through an 11-micron mesh 

• 3 replicates per treatment

• 500 µL of nutrients added

• 5 days

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

p = 0.08, no significance 

p = 0.10, no significance

Discussion

• Woodland Pond: – Variation? – Nitrogen– Zooplankton – Clumping of algae – Light

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

Further Research

• Maximum production rate• Seasonal Variation • Controlled experimentation on mixotrophic

protists• Specific species present in each

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.