U.S. Geological Survey Toxic Substances Hydrology Program--Proceedings
of the Technical Meeting, Colorado Springs, Colorado, September 20-24, 1993,
Water-Resources Investigations Report 94-4015
A Survey of Molecular Marker Compounds in Sediments of San Francisco
Bay, California
by
Frances D. Hostettler (U.S. Geological Survey, Menlo Park, CA),
John B. Rapp (U.S. Geological Survey, Menlo Park, CA), Wilfred E. Pereira
(U.S. Geological Survey, Menlo Park, CA),and Keith A. Kvenvolden (U.S. Geological
Survey, Menlo Park, CA)
Abstract
An areal survey of surficial sediments in San Francisco Bay has been
conducted to evaluate the presence of extractable organic compounds. Molecular
marker compounds studied include hydrocarbons (PAH's), chlorinated pesticides,
and other organic compounds that provide information on sources of organic
input into the Bay. Fairly uniform source profiles are seen throughout the
Bay. Biomarker profiles contain mature constituents indicating anthropogenic
influences and extensive sediment reworking. The dominant input signatures
in San Francisco Bay sediment are those of anthropogenic PAH's from combustion
and other sources, and long chain n-alkanes and n-aldehydes
from terrigenous vascular plants. A comparison of the sums of the combustion
PAH's and the terrigenous n-alkanes shows that an anthropogenic influence
is dominant in the most urban parts of the Bay close to shore, and in mid-Bay
channel areas, and a terrigenous signature is dominant nearshore in San
Pablo Bay and at the southernmost station in South Bay.
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