. Ecological study of the Amoco Cadiz oil spill : report of the NOAA-CNEXO Joint Scientific Commission . FIGURE Offshore surface sediment and l'Aber Benoit sampling locations (Marchand, Courtot). Hydrocarbon concentrations and source classifications for the entire data set are shown in Table 8. Individual aromatic hydrocarbon determinations by GC/MS appear for several time series in Tables 9 through 13 and for two of the L'Aber Benoit samples in Table 14. An instructive way of viewing the time series information is presented in Figures and At both the Terenez/ Morlaix and lie
. Ecological study of the Amoco Cadiz oil spill : report of the NOAA-CNEXO Joint Scientific Commission . FIGURE Offshore surface sediment and l'Aber Benoit sampling locations (Marchand, Courtot). Hydrocarbon concentrations and source classifications for the entire data set are shown in Table 8. Individual aromatic hydrocarbon determinations by GC/MS appear for several time series in Tables 9 through 13 and for two of the L'Aber Benoit samples in Table 14. An instructive way of viewing the time series information is presented in Figures and At both the Terenez/ Morlaix and lie Grande time series, concentrations increased between April and July 1978. In the case of the Terenez samples, the increase is due to offshore transport of weathered oil as evidenced by 1) an increase in absolute concentrations, 2) a decrease in the ALK/ISO ratio, and 3) an increase in phenanthrenes (total P, CL, C2, C3, C4P) and dibenzothio- phenes, without an accompanying increase in the pyrogenic PAH compounds (m/e 202). However, the lie Grande benthic samples show an increase in total hydrocarbons along with increases in the aromatics including the pyrogenic PAH. This latter finding indicates that both petroleum hydrocarbons and combustion-related PAH material are being transported to and deposited in the offshore sediments near lie Grande by a similar mechanism, most likely in association with suspended matter from riverine plumes. Figure , a plot of phenanthrene and its alkyl homologues at the Morlaix Station (Station B), reveals that while the source of the phenanthrenes is petroleum in July 1978, as evidenced by the greater abundance of alkylated compounds versus the parent (unsub- stituted) compounds, the input in February of 1979 is largely pyrogenic ( greater amounts of parent phenanthrene). This illustrates both the usefulness of detailed GC/MS-derived data and their subsequent presentation in alkyl homologue distribution plots. 63
Size: 2880px × 1736px
Photo credit: © The Bookworm Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectionameri, bookcollectionbiodiversity
