Thomas R. Fisher

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We modeled nutrient export in the Choptank River Basin on the coastal plain of the Chesapeake drainage, using a modified version of a lumped-parameter, hydrochemical model (GWLF). Calibration was performed using long-term (WY1980–WY1990) hydrochemistry data from a gauged site. The calibrated model reproduced water yields, TN, and TP export with cumulative(More)
Phytoplankton abundance in tropical lakes is more often judged to be limited by nitrogen than phosphorus, but seldom does the evidence include controlled enrichments of natural populations. In January 1980 we performed the first experimental fertilization in an equatorial African soda lake, Lake Sonachi, a small, meromictic volcanic crater lake in Kenya.(More)
Restoration of the Chesapeake Bay, the largest estuary in the United States, is a national priority. Documentation of progress of this restoration effort is needed. A study was conducted to examine water quality in the Choptank River estuary, a tributary of the Chesapeake Bay that since 1998 has been classified as impaired waters under the Federal Clean(More)
Land-cover changes in the Choptank basin were estimated for 1665–1820 by using historical socioeconomic data and crop-rotation models. Socioeconomic data (human population, output per laborer, and crop yields) were obtained from the literature, whereas crop-rotation models, based on historical records, represented how agriculture was practiced. Model(More)
Excess nutrients and agrochemicals from non-point sources contribute to water quality impairment in the Chesapeake Bay watershed and their loading rates are related to land use, agricultural practices, hydrology, and pollutant fate and transport processes. In this study, monthly baseflow stream samples from 15 agricultural subwatersheds of the Choptank(More)
The business community has learned the value of design thinking as a way to innovate in addressing people's needs--and health systems could benefit enormously from doing the same. This paper lays out how design thinking applies to healthcare challenges and how systems might utilize this proven and accessible problem-solving process. We show how design(More)
Title of dissertation: EVALUATION OF AGRICULTURAL NUTRIENT REDUCTIONS IN RESTORED RIPARIAN BUFFERS Adrienne J. Sutton, Doctor of Philosophy, 2006 Dissertation directed by: Professor Thomas R. Fisher University of Maryland Center for Environmental Science Horn Point Laboratory Efforts to restore the Chesapeake Bay have focused on reducing agricultural(More)
Title of Document: RESTORATION ECOLOGY OF POTAMOGETON PERFOLIATUS IN MESOHALINE CHESAPEAKE BAY: THE NURSERY BED EFFECT Angela M. Hengst, Master of Science, 2007 Directed By: Research Associate Professor, Dr. Laura Murray, Marine, Estuarine and Environmental Science Restoring once prominent species of submerged aquatic vegetation (SAV) back into Chesapeake(More)