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Characterization of the actual state of oil contamination in a beach
affected by the Prestige oil spill – the O Rostro beach
Raquel Almeida 1 , Paula Guedes 1 , Nazaré Couto 1,2 , Ana P. Mucha 1 and C. Marisa R.
Almeida 1
1 CIMAR/CIIMAR – Centre of Marine and Environmental Research, University of Porto, Portugal.
2 Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, Portugal
Oil spills can become a serious environmental problem as they affect sensitive marine areas
and may be implicated in producing changes on natural ecological development. Furthermore,
they also have negative effects on local economic activities, constituting a challenge for
strategic contingency management. Studies from the Prestige oil spill, that occurred on the 13 th
November of 2002 and which seriously affected the “Costa da Morte” (Galicia, NW Spain),
indicated that subsurface oil can reach depths well beyond the estimations currently used in
cleanup strategies and that methodological approaches for the evaluation and monitoring of
“deep buried” subsurface oil are needed. As a result, this work was focus in a case study
carried out in the intertidal section of the “O Rostro” beach, located within the inner area of
Lires Ría (Galicia, NW Coast of Spain), an area affected by the Prestige oil spill.
The main experimental objective was to have a preliminary characterization of the actual sate
of subsurface oil contamination of this beach. For that, two cores (≈ 2m depth) were collected
in the selected beach. Total petroleum hydrocarbons contents were determined in diverse
sediment samples of the cores (in selected depths) by Fourrier Transform Infrared
Spectroscopy (FTIR) after their extraction by sonication.
Obtained results indicated that oil was still present at different depths in the “O Rostro” beach.
In addition, results indicated that a significant amount of the detected hydrocarbons were
volatile and that they were not homogeneously distributed within the sediment.
These hydrocarbon results are only initial indicators of oil being present in the selected beach.
The actual state of contamination will be accessed by analyzing selected hydrocarbons (namely
aliphatic hydrocarbons and PAHs) in other cores collected specifically for that purpose.
Acknowledgments: This work was partially financed by project OILDEBEACH (ERA-
AMPERA/0003/2007). Authors acknowledge FCT for the BII scholarships of R. Almeida and P.
Guedes (CIIMAR/C2008/BII/01-25) and PhD scholarship of N. Couto (SFRH/31816/2006).
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