Sestonic Chlorophyll in Missouri's streams and rivers

This dataset comprises sestonic chlorophyll a (Chl-a) data collected from streams and rivers in Missouri between 1978 and 2009. The data comes from dissertations, theses, and focused stream studies by students and staff from the University of Missouri Limnology Lab. In addition to sestonic Chl-a, the dataset includes total phosphorus (TP) and total nitrogen (TN), and watershed characteristics such as watershed area, mean watershed slope, and land use. Chlorophyll-a was corrected for pheophytin and analyzed by fluorometric analysis following U.S. Environmental Protection Agency method 445.0, modified using heated ethanol extraction without homogenization (Sartory and Grobbelaar, 1984) and a fluorometer equipped with a flow-through cell (Knowlton, 1984). Chlorophyll was extracted in acetone/dimethyl sulfoxide (Stauffer et al. 1979) prior to 1986. Starting in 1986, chlorophyll was extracted in ethanol (Sartory & Grobbelaar 1984). TN and TP analysis were conducted by spectrophotometry using persulfate digestion and cadmium reduction for TN and ascorbic acid for TP. The laboratory methods used are described in detail in Jones, Argerich et al. (2020), and the same laboratory was utilized throughout the studies, with minor variations in methodology being cross-checked over time. We used ArcInfo GIS based on 1-m resolution digital elevation data to estimate stream watershed area and mean watershed slope. Land cover was obtained from 30-m imagery from the LANDSAT thematic mapper developed by the Missouri Resource Assessment Partnership.