1. Acknowledgments We would like to thank Dr. Evans for this opportunity to learn about yellow boy, Dr. Van de Ven for providing GIS and GPS equipment as well as aerial photographs of the study sites, Dr. McGrath for her information on yellow boy from her previous study. Finally, we would like to thank TDEC for putting a halt on production of new man-made lakes. Introduction Yellow boy forms from iron and manganese oxide precipitating out of stream water and occurs naturally in Sewanee, TN in the outlet streams of the Lake Cheston, Lake Dimmick, and Lake O’Donnell dams. Usually yellow boy appears as a yellowish- orange to brown pigment within in the drainage streams. This ferric hydroxide precipitate can act as a blanket of pollution that is potentially harmful to aquatic flora and fauna; therefore, it has capability of destructing natural ecological processes. Due to the potential harm yellow boy has on habitats and ecological systems, the Tennessee Department of Environment and Conservation (TDEC) has forbid the construction of further man-made lakes on the plateau. This is partially due to lack of understanding of possible adverse outcomes of the pollution, which could come from run-off streams that stem from the lakes. (McGrath 2011) The GPS points were then transferred to a computer and converted to a layer in ArcMap. Using the points, we created three separate maps showing the extent of yellow boy in the drainage streams as well as the pooled areas of yellow boy. Using ArcMap analysis, we calculated the surface area of the lakes, surface area of yellow boy pools, and length of yellow boy in the streams. Using this information, we created a table and graph to show the relationship between lake size and the amount of yellow boy drainage. Relating our results to our hypothesis. Conclusion This compilation of data reputes our hypothesis for Lake Cheston and Lake Dimmick, which stated that the amount of yellow boy precipitate would be greater in the streams draining from larger lakes. Probable explanations: Size of the lake is not the only determining factor; other contributors could include geological strata of the lake basin. - Barnes and Romberger (1968) research concluded that the presence of geological bicarbonate concentration in would lessen the presence of yellow boy. Dilution of yellow boy in run off streams due to lake overflow pathways. For Lake O’Donnell, our hypothesis was also proven incorrect. This was probably due to: The water for usage was drained from the lake bed, and further filtration of the drained water removed all the yellow boy from the water. The presence of yellow boy was seen as a threat to the aquatic life, because it coats the surface layer of streams, depleting the lower levels of the stream of oxygen. Through our observation at Lake Cheston we only saw aquatic life when the runoff stream was devoid of yellow boy. However, the nature of yellow boy is not fully understood; therefore further investigation into this matter is needed. Yellow Boy in Outlet Streams of Lake Dams on Sewanee Domain Department of Biology and Environmental Studies Program Combined Class Project: Biol 222 - Advanced Conservation Biology: Thao Bui and Senemeh Buist-Baker (Dr. Evans) EnSt 217 - Fundamentals of GIS: Meghan Stuart (Dr. Van de Ven) Literature cited Barnes, H. L. and S. B. Romberger. 1968. Chemical Aspects of Acid Mine Drainage. Journal (Water Pollution Control Federation) 40:3 371-384. Gorenflo, L. 2011. Cumberland Sustainable. Retrieved 21 March 2011. www.cumberlandsustainable.org/files/Comments. doc McGrath, D. Personal Interview. 7 March 2011. Robb, G. A., and J. D. F. Robinson. 1995. Acid Drainage from Mines. The Geographical Journal 161:1 47- 54. Van de Ven, C. Email received from Meghan Stuart. 21 March 2011. Figure 4. Amount of Yellow Boy Drainage Compared to Lake Size. The linear relationship between the size of each lake and: a) length of yellow boy in streams and b) area of yellow boy pools at the dam outlets of each lake. Figure 3(a-c). Maps showing yellow boy stream drainage from the dams in (a) Lake Cheston, (b) Lake O’Donnell, and (c) Lake Dimmick in Sewanee, TN Spring 2011. The legend and scale are the same for all three maps. Figure 1. Yellow boy in drainage stream from Lake O’Donnell dam in Sewanee, TN April 9 th, 2011. Concerns in regard to the yellow boy spread include: the destruction of down-stream aquatic life, the decimation of aesthetic values on the plateau, and degradation of drinking water quality and natural watersheds. (Gorenflo 2011) Thus, the study of natural occurrence of yellow boy on the plateau has become an interest for conservation purposes. However, this project is not in the nature of a research for preventive measures. Instead, the focus is on the relation between the size of the man-made lakes and the distance of the yellow boy spread in run-off streams. Therefore, we hypothesized: The amount of yellow boy present in the runoff stream and the surface area of the accumulated yellow boy in pool at the end of the runoff stream in Lake Dimmick will be greater than Lake Cheston Lake O’Donnell, the Sewanee domain’s main source of water, is drained daily from the bottom; therefore, the yellow boy will be abundant in the runoff stream and the accumulated yellow boy pool at the end of the stream because the bottom of the lake is being disturbed. Materials and Methods Materials Used: Garmin Etrex Venture HC GPS Plastic waders We visited each lake on Saturday April 9 th, 2011. Our study focused on the outlet streams coming from the dams of Lake Cheston, Lake O’Donnell, and Lake Dimmick. At each stream, GPS points were taken to measure the point at which the stream with yellow boy percolated from the dam and the point at which the precipitate was no longer visible. Points were also taken to outline the areas with yellow boy presence. a)b)c) Lake Surface Area of Lake (m 2 ) Yellow Boy Length in Outlet Stream (m) Yellow Boy Surface Area (m 2 ) Cheston 26,4494433 O’Donnell 88,075268 Dimmick 351,864176 Table 1. Spatial analysis data showing the relationship between the size of the lake and the length of yellow boy drainage and amount of yellow boy at the dam outlets. Sewanee, TN Spring 2011. Results Figure 3 a-c shows the spatial length of the yellow boy run off streams for Lake Cheston, Lake O’Donnell, and Lake Dimmick. GIS analysis shows that Lake Cheston has the smallest surface area, whereas Lake Dimmick is the largest lake in this study. Lake Cheston has the greatest amount of yellow boy precipitation, whereas Lake Dimmick has the least. Figure 2. Location of Lake Cheston, Lake O’Donnell, and Lake Dimmick on the Sewanee Domain in Spring 2011