download 21.6mb - Oil-Spill-Info.com

147, 156, 170, 178, 184, 192, 198, 206, 212, 220, and 226. The
representative compounds were naphthalene, methyl naphthalene, HMB as an
interanal standard, dimethyl naphthalene, trimethyl naphthalene,
phenanthrene, dibenzothiophene, methyl phenanthrene, methyl
dibenzothiophene, dimethyl phenanthrene, dimethyl dibenzothiophene,
trimethyl phenanthrene, and trimethyl dibenzothiophene, respectively.
The dwell time per ion was 10 msec. Instrument response factors were
calculated by injecting known quantities of unsubstituted and C and C„
substituted authentic aromatic hydrocarbons and determining the
integrated response for each compound. These values were used to
extrapolate for quantitation of isomers and C_ substituted compounds.
For analysis of the polar fraction including microbial degradation
products, three samples were selected for analysis by the University of
New Orleans Center for Bio-organic Studies. The samples were: 1) flow
through, 6 week incubation from site 6; 2) flow through, 6 week
incubation from site 7; 3) agitated flask, 6 week incubation from site
7. Frozen samples were sent for analysis. At the Center for
Bio-organic Studies the samples were extracted with successive portions
of CH OH, CH OH/CH CI and CH CI . The extracts were fractionated using
silica gel and the f_ fraction was collected, methylated and analysed by
high resolution GC-MS .
RESULTS AND DISCUSSION
The enumeration of hydrocarbon utilizing microorganisms indicated
that numbers of hydrocarbon utilizers in the intertidal sediments
increased significantly in response to hydrocarbon inputs (Table 2).
Site 3, which is covered with seawater only at times of extreme high
tide, showed very high populations of hydrocarbon utilizing
microorganisms even three years after the AMOCO CADIZ spillage. Sites 5
and 6 (located within Aber Wrac'h) and Sites 7 and 8 (located near
Portsall) showed variable, but apparently elevated, numbers of
hydrocarbon utilizers for up to two years following the spill. It
appears that hydrocarbons contained within the mud sediments of Aber
Wrac'h continued to exert a selective pressure on the microbial
community that favored elevated populations of hydrocarbon utilizers for
a longer period of time than sites on high-energy sand beaches. Site 2
showed evidence that the TANIO spill impacted the lie Crande region.
This site did not show elevated numbers of hydrocarbon utilizers in
December 1978 or at later sampling times as a result of the AMOCO CADIZ
spill, but in July of 1980, several months after the wreck of the TANIO,
numbers of hydrocarbon utilizers were greatly elevated. A year later,
however, the numbers of hydrocarbon utilizers had returned to background
levels at this site. The unoiled control sites 9 and 10 and sites 1 and
4, which were impacted by the AMOCO CADIZ spill, did not show any
evidence of elevated hydrocarbon-utilizing populations during the
sampling period. Similarly, the offshore sites A-D in the Bay of
Morlaix did not appear to be elevated at the time of sampling in
November 1979. Sites 11 and 12 were added following the wreck of the
TANIO and showed obviously elevated populations of hydrocarbon utilizers
that persisted for over a year.