Oyster Beds and Climate History
Location of exposed and buried oyster beds near the Tappan Zee bridge.
While carrying out the Hudson River Benthic Mapping Project, extensive fossil oyster beds were discovered to have once flourished along the marginal flats of the river from Piermont to Haverstraw Bay. Radiocarbon dating indicates that oysters populated this region during two distinct time periods: prior to approximately 5000 years ago and between approximately 500 and 300 years before the present day.
Both periods agree with the chronology of oyster shells found in the Dogan Point shell midden left by indigenous peoples in Westchester County. These also coincide with recent warming events, including the Mid-Holocene Hypsithermal Interval approximately 4,000 to 6,000 years ago and the Roman to Medieval Warm period between 400 and 1200 A.D. The most recent disappearance of oysters between Piermont and Haverstraw Bay coincides with the onset of the Little Ice Age and could reflect the effects of cooler spring temperatures during crucial juvenile phases as well as erosion of oyster beds caused by ice rafting during more severe winter conditions.
Carbotte S.M., R.E. Bell, W.B.F. Ryan, C. McHugh, A. Slagle, F. Nitsche, J. Rubenstone and R. Flood, "Environmental change and oyster colonization within the Hudson River estuary linked to Holocene climate," Geo-Marine Letters, 24(2004): 212-224.