Paul Lake (MI): long-term reference lake in Cascade Project, 1984-2007

Lake data were obtained from Stephen Carpenter and from the long-term study of lakes at the University of Notre Dame Environmental Research Center (UNDERC) known informally as the “Cascade Project.” This project has resulted in multiple publications, including Carpenter & Kitchell’s 1993 book “The Trophic Cascade in Lakes.” Chapter 2 of this book has descriptive information about the study site. Routine sampling occurred weekly-monthly during summer months, with a few rare inclusions outside of the May-Aug period. Samples were collected from a fixed transect in the lake. Sampling frequency and variables that were measured/reported vary from year to year as a function of the specific focus of the active grant at the time (and budgetary constraints). Samples were collected either at the surface (reported as 0 m) or were integrated samples for the epilimnion (referred to as PML, or pool mixed layer by this group) with water collected using a Van Dorn bottle from 0, 1, and 2 m (usually-or from top, middle, and bottom of mixed layer) and pooling equal volumes of water from these three depths.