Document Type

Thesis

Abstract

Population levels of Eastern Oysters (Crassostrea virginica) in the Chesapeake Bay have severely declined due to disease, sediment influx, pollution, and overharvesting. To restore these populations, it is essential to establish baseline data on healthy reefs for conservation efforts. This study focuses on a well-preserved late Pleistocene oyster deposit on the Piankatank River, Virginia. Temperature, salinity, and tidal current data are compared to modern environments. Dating of the reef through amino acid racemization allows these environmental factors to be placed in an age specific context that can then be applied to modern conservation efforts. The Holland Point reef thrived approximately 125 Ka during the interglacial Marine Isotope Stage Se. It was a shallow dipping fringing reef running from north to south. Oysters oriented themselves to make use of a variety of paleotidal current directions in the region, notably those following the orientation of the proto-Chesapeake Bay and the proto-Piankatank River. Salinity tolerance ranges of molluscan species preserved in the reef range between 15-32 ppt, higher than the modern day river. The peak temperature during the oyster growth season was 14.1 +/- 5°C, cooler than the modern river. These conditions likely allowed the Holland Point reef to reach its high levels of productivity and conservation efforts should be focused on similar region in the modern to achieve optimal results.

Date Awarded

2013

Department

Geology

Advisor 1

Rowan Lockwood

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