Eastern oyster aquaculture : estuarine remediation via site suitability and spatially explicit carrying capacity modeling in Virginia’s Chesapeake Bay

Abstract: Scientific summary Estuarine eutrophication, the systemic limitation of dissolved oxygen in a body of water, has been increasingly monitored and scrutinized as an environmental concern needing acute and long term remediation efforts. The driving factors of eutrophication are largely attributed to anthropogenic sources within the watershed, sources that are products of modern civilization. Estuarine eutrophication poses significant threats to aquatic ecosystems at micro and macro scales, as well as to coastal economies. This paper addresses bivalve mollusk aquaculture as a managed remediation mechanism for reducing eutrophication through modeling and analysis within the Geographic Information Systems (GIS) paradigm. In realistic application of such mechanisms, spatial delineation of appropriate areas for implementation and potential impacts on eutrophic states must be efficiently predicted; GIS is the ideal platform to bridge data and analyses of interest in this light. Aquaculture site suitability is determined by integrating spatial data in the GIS framework to yield discrete areas of suitable and unsuitable areas. Eutrophic state impacts are determined by juxtaposing suitable areas at their present eutrophic condition against modeled shifts in eutrophic states due to intervention by bivalve aquaculture. In this case, bivalve aquaculture production carrying capacity is used as the benchmark to model effects in eutrophic conditions. This methodology is applied to Eastern Oyster aquaculture in the Chesapeake Bay of Virginia, USA. The Chesapeake Bay is an exemplary case for this theme as it is the country’s largest estuary and has gained notoriety for its eutrophic state. Intensive oyster aquaculture is a burgeoning industry with historical significance to the region as well as presenting an economically viable method for estuarine eutrophication remediation. Oyster aquaculture site suitability, eutrophic conditions, spatially explicit aquaculture carrying capacity, and potential eutrophic state changes are modeled and analyzed in this thesis through the means of GIS.