A trophic state analysis of selected lakes and ponds in Yellowstone National Park

Hunt, Laura

Beginning in 1998, Dr. A Woodruff Miller of Brigham Young University began sampling different water bodies located in Yellowstone National Park. These samples were collected in order to determine the trophic state of different lakes and ponds. The main focus of this study is to determine the trophic state of each of the water bodies sampled from 2012 through 2016. Three different models used to determine the trophic state are the Carlson Model, The LarsenMercier Model, and the Vollenweider Model. The second part of this study was to analyze all of the data collected for each water body beginning from 1998 and identify trends in phosphorus and chlorophyll-a concentrations, the Carlson trophic state index, and any inlet or outlet phosphorus concentrations. During the span of this study, the trophic state classifications ranged from slightly oligotrophic to hyper-eutrophic. Five lakes averaged a trophic state of strongly eutrophic. These lakes are Feather Lake, Floating Island Lake, Hot Beach Pond, Indian Pond, and Nymph Lake. Eight lakes averaged classifications of slightly eutrophic or eutrophic. These lakes are Buck Lake, Hazel Lake, Lower Basin Lake, North Twin Lake, Pool by Morning Glory Pool, Scaup Lake, Trout Lake East, and Turbid Lake. Lakes that appear to be advancing in the eutrophication process are Hot Lake, Pool by Morning Glory Pool, Scaup Lake, Terrace Springs, Trout Lake West, and Yellowstone Lake at Bridge Bay. Feather Lake and Riddle Lake both have trends that indicate a reversal of the eutrophication process.