Chlorophyll and DO Analysis of a Duck Pond Limnologists: Kyle Hewitt and Willie Adams images/Male%20Wood%20Duck%201.jpg
Why is analysis of chlorophyll and DO levels in a Colorado Springs duck pond important? Reveals the extent to which the pond has been eutrophied AND Indicates the effect that this eutrophication has had on photosynthetic productivity at various locations in the pond Eutrophication: The influx of nutrients into an aquatic ecosystem characterized by decreasing dissolved oxygen levels. fisheries/227_305.jpg
Effect of Waterfowl Populations As previous research has indicated water fowl populations have been known to cause pond eutrophication as a result of their significant contribution to the increase of nutrients (Hermanson 1999). This has a direct effect on primary productivity
Hypotheses Chlorophyll levels in clear lakes are ~ 2 x ug/ml (Krause-Jensen 1998). Levels at the duck pond will be significantly higher. Furthermore, chlorophyll levels will be higher at the north end of the pond than the south as a result of increased sunlight and wind. Finally Chlorophyll levels will be highest just below the suface (10cm)
Methods Field Equipment Used: Sea King Row Boat (complete with paddles and life-jackets) ml semi-transparent sample jars Kemmerer DO Meter Cooler Digital Camera
Sample Locations: Three sites in center North Side Shore South Side Shore “We’re gonna need a bigger boat!”
Depth Variation This is a kemmerer! It is used to take water samples at different depths. This is Willie! He’s in a boat. TopMiddleBottom 10cm0.75m1.5m 18.7 º C16.1 º C14.2 º C
North Sunny Windy Water temperature 19.6º C Large rocky shore South Shady Calm Water temperature 18.5º C Gradual sandy Shore
Later on, back in the lab Procedure Day 1 Filter 250ml of sample Place filter in methanol Lab Equipment Used Vacuum Filter Glass Fiber Filter Paper Filtration Funnel 90% Methanol Petri dish 90% Acetone 1 cm cuvettes 1 M HCl Spectrophotometer
24 hours later... Procedure Day 2 Mix 4 ml methanol solution with 4 ml acetone Take spectrophotometer readings at 665 and 750 nanometers. Then add HCl and repeat. Chlorophyll conc. (ug/ml)=26.7*(665b-665a)
Results Depth Bar graph showing values of chlorophyll concentration obtained at each location and depth (Mean +/- SD, n=3)
Results cont. Depth Bar Graph showing values of dissolved oxygen at various locations and depths (mean +/- SD, N=3)
More Results…… Scatter plot illustrating correlation between chlorophyll concentrations and DO for each sample
Discussion The little gosling that couldn’t…. Attack of the Koi! rotate/koi.jpg
Concluding Statements Pond has not yet entered a eutrophic state - - possibly mesotrophic. Possible reasons for higher production on north side: More Sunlight More Nutrient Cycling (wind) Landscape, Vegetation, Disturbance Respiration is greater and photosynthesis lower at 1.5 meters Further research... “Chlorophyll? More like borophyll!!!” -Billy Madison
Literature Used: Arar EJ. (1997) Determination of Chlorophylls a and b and Identification of Other Pigments of Interest in Marine and Freshwater Algae Using High Performance Liquid Chromatography with Visible Wavelength Detection. From: National Exposure Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency. Baron JS. (2003) Sustaining Healthy Freshwater Ecosystems. Issues in Ecology. No. 10. Dineen CF. (1953) An Ecological Study of a Minnesota Pond. American Midland Naturalist, Vol. 50, No Johannessen T, E Dahl (1996) Declines in Oxygen Concentrations Along the Norwegian Skagerrak Coast, : A Signal of Ecosystem Change Due to Eutrophication? Limnology and Oceanography. Vol. 41, No 4, Krause-Jensen D et al. (1998) Light Attenuation and Photosynthesis of Aquatic Plant Communities. Limnology and Oceanography. Vol 43, no 3, Latif Z et al. (2000) Evaluation of Water-Quality by Chlorophyll and Dissolved Oxygen. Steinman AD and GA Lamberti. (1996) Biomass and Pigments of Benthic Algae. Methods in Stream Ecology.
Questions?? cO7ntMxSIJ: unity.middlebury.edu/~dsanford/figaro/question.jpg