Temporal variation in the levels of polycyclic aromatic hydrocarbons (PAHs) off the Galician Coast after the ‘Prestige’ oil spill

Abstract

We studied the temporal variation of polycyclic aromatic hydrocarbons (PAH) levels in the wild mussel Mytilus galloprovincialis, water and sediment from 3 sampling sites on the Galician coast of Spain between the rias of Arousa and Muros, which were dramatically affected by the large oil spill from the oil tanker 'Prestige'. The samples were collected periodically, from November 22, 2002, 3 d after the tanker sank, until December 23, 2003. The total hydrocarbon content in the water and sediment samples was determined by fluorescence and expressed as concentration of chrysene. In addition, individual PAHs -analytes recommended by the US Environmental Protection Agency -were analysed in the mussel samples by HPLC using fluorimetric detection. A maximum concentration of 2.07 × 10 3 µg equiv. of chrysene l -1 was found in the water column at the sampling site of Furnas on November 29, 2002 which decreased to 0.21 µg l -1 by October 2003. Likewise, the concentrations of the sum of the 16 PAHs determined in the mussel samples collected at the sampling points were between 2.5 × 10 3 and 5.9 × 10 3 µg kg -1 dry weight in the days immediately following the oil spill and then decreased to 0.13 × 10 3 µg kg -1 in October 2003. However, no relevant information could be obtained from the PAH content of the sediment samples. A relation between parent PAHs accumulated in the mussels and their molecular weight (MW) has been found to provide an indication of hydrocarbon pollution. A good approximation was obtained when the total PAH content (ΣPAH) was represented versus the ratio of low MW PAHs to high MW PAHs (ΣLPAH:ΣHPAH). When the depuration rate r of individual PAHs by the mussels was fitted to an exponential model, 2 different values of r were found depending on the PAH concentration. The change from a slow to fast depuration rate was produced when the logarithm of the concentration was 1.0. KEY WORDS: 'Prestige' oil spill · PAH analysis · Mytilus · Mussels · Temporal variation Resale or republication not permitted without written consent of the publisher

Advanced PAH pollution monitoring by bivalves

“…Pereira et al (2011) selected another estuary in NW Spain for monitoring PAH pollution in bivalve species. The TPAH concentrations were comparable to those reported form moderately contaminated areas; however, additional concern has been raised since in one sampling point the respective values were higher than those obtained in mussels 3 days after the Prestige shipwreck (Nieto et al 2006).…”

“…In general they are efficacious and can satisfactory address the need for substantial detection and quantification of PAH. An issue which might pose some concern over these methods is that they usually-and if targeting a large number of PAH-require prolonged runtimes, which in some cases reach 60 min (Nieto et al 2006).…”

“…On November 13, 2002, the oil tanker ''Prestige,'' which carried 77,000 t of heavy fuel-oil, began to leak oil, ending up polluting more than 1000 km of coastline, especially affecting Galicia. Nieto et al (2006) presented work on PAH pollution effect on bivalves immediately after the ''Prestige oil spill.'' RPAH ranged from 2500 to 5900 ng/g dw, which clearly indicated that the oil spill affected the pollution status of bivalves in this region, with concentration being nearly one order of magnitude higher than the concentration range of least contaminated sites.…”

Monitoring of PAHs and alkylated PAHs in aquatic organisms after 1 month from the Solar I oil spill off the coast of Guimaras Island, Philippines

“…Nieto et al (2006) reported that the maximum concentration of total PAH (13 PAHs) was 5.9 mg/kg dry weight in Mytilus galloprovincialis 2 months after the Prestige oil spill. Soriano et al (2006) also reported that the concentration was above 1,000 to 7,780 μg/kg dry weight in M. galloprovincialis Concentration (ng/g dry) at sites most affected by the Prestige oil spill after 2-3 months.…”

Integrated assessment of water quality of the Costa da Morte (Galicia, NW Spain) by means of mussel chemical, biochemical and physiological parameters

“…In most of these studies mussels were used as bioindicators both to determine the change over time and distribution of accumulated hydrocarbon levels (Nieto et al 2006;Soriano et al 2006) and to study their biological effects Marigómez et al 2006;. However, there have been fewer integrated studies involving chemical appraisals and biological determinations performed on the same sample of mussels.…”