Long-Term History of Chesapeake Bay Anoxia

Science  15 Nov 1991:
Vol. 254, Issue 5034, pp. 992-996
DOI: 10.1126/science.254.5034.992


Stratigraphic records from four sediment cores collected along a transect across the Chesapeake Bay near the mouth of the Choptank River were used to reconstruct a 2000-year history of anoxia and eutrophication in the Chesapeake Bay. Variations in pollen, diatoms, concentration of organic carbon, nitrogen, sulfur, acid-soluble iron, and an estimate of the degree of pyritization of iron indicate that sedimentation rates, anoxic conditions and eutrophication have increased in the Chesapeake Bay since the time of European settlement.