Document Type
Thesis
Abstract
A paleoecological study of the changes in relative abundance of benthic ostracodes in Pocomoke Sound, in the southern Chesapeake Bay, has revealed a highresolution history of faunal indicators of water quality. Data from two sediment cores reflect three distinct ostracode assemblages that occur within the last 150 years from which water quality conditions can be inferred. The interval from late-1700s to 1945 is marked by the fluctuating dominance between Perissocytheridea brachyforma, a mesohaline species, and Cyprideis mexicana, a polyhaline species, both of which require oxygenated water to survive. After 1945, Actinocythereis captionis, Cytheromorpha newportensis, Cytherura sp., Leptocythere nikraveshae and Loxoconcha sp. experienced a large drop in abundance, which corresponds to a decrease in overall benthic diversity. At about the same time, the abundance of Cytheromorpha curta increased sharply, signifying a decline in oxygen levels and/or increase in turbidity. After 1960, Megacythere repexa, another species tolerant of low oxygen, began a steady rise to dominance. These faunal patterns are similar to those found in other parts of the Bay suggesting near synchronous bay-wide changes in benthic conditions in response to landuse changes and water quality.
Date Awarded
2004
Department
Geology
Advisor 1
Heather MacDonald
Recommended Citation
Edwards, Amy L., "Influences of Historical Land-use Change on Chesapeake Bay, Reconstructed from Environmentally Sensative Benthic Ostracodes" (2004). Geology Senior Theses. William & Mary. Paper 130.
https://scholarworks.wm.edu/geologyseniors/130
