Gschwend%20thesis.pdf

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indicated that these hydrocarbons resulted from biological inputs. It is
known that benthic algae contain pentadecane and heptadecane, and a calcu-
lation demonstrated that it was reasonable to propose that these algae
were the source of these saturated hydrocarbons.
i
The C2- and C3-benzenes concentrations covaried temporally in coastal
seawater. They were most concentrated after the oil spill and after summer
weekends. Sumer weekends are peak periods of tourist and recreational
activities in this coastal region, and strong inputs of C2- and C3-benzenes
were attributed to the uses of fossil fuels during these activities.
An unknown compound (ro 108) was found at about 20 ng/kg in coastal
seawater of Vineyard Sound in February and March, 1978. GC retention data
and mass spectra showed that it was identical to the unknown compound
recovered from off Peru and was similar to fucoserraten, the sexual
chemotactic agent utilized by benthic algae, Fucus. The appearance of this
unsaturated hydrocarbon compound coincided with the time of year in which
Fucus were expected to be reproductively active. As was the case for the
region off Peru, rapid isomerization of fucoserraten may have yielded
the observed unknown compound.
Naphthalenes were found in coastal seawater at about lng/kg in the
sumer, and as high as 5-10 ng/kg in the winter. The naphthalene to
methyl naphthalenes ratios of the temporal study samples oscillated sinu-
soidally such that maximum ratios near 1.6 were found in the winter while
minimum values of 0.8 appeared in the sumer. This may be due to more
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indirect inputs (e.g. via the atmosphere) of
A
naphthalenes
.
to coastal
.
seawater in the winter allowing more fractionation of these homologues.
C6-CIO aldehydes were also found in all the biweekly seawater samples
from Vineyard Sound. The concentrations of these compounds increased