Diatoms in Sediment Cores From the Mesohaline Chesapeake Bay, U.S.A.

Diatoms were extracted from subsampled sections of four dated sediment cores collected in the mesohaline Chesapeake Bay, U.S.A. Over 400 species in 76 genera were identified. A complete list of the species identified from the cores is given, together with information on their relative abundance. Forty-six of the more abundant taxa are described and illustrated, with notes on their autecology and relative abundance through time. The diatom community exhibits changes through time, such as a decline in diversity and a shift to predominantly pelagic species, with land-use changes that have occurred since European settlement of the Chesapeake Bay watershed. Many species observed in older sediment samples have apparently not been reported previously for Chesapeake Bay.