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FISTERRA AGUIÑO I. CIES Purple sea urchin- Paracentrotus lividus 0 50 100 150 200 250 jan-03 mar-03 apr-03 may-03 jun-03 jul-03 aug-03 sep-03 oct-03 nov-03 dec-03 jan-04 feb-04 mar-04 apr-04 nov-04 Sum 6 PAHs (μg kg-1 d.w. Aguiño I.Cíes Fisterra Guide value Figure 2. Evolution of the sum of 6 PAHs in purple sea urchin 0 50 100 150 200 250 300 350 400 450 jan-03 mar-03 apr-03 may-03 jun-03 jul-03 aug-03 sep-03 oct-03 nov-03 dec-03 jan-04 feb-04 mar-04 apr-04 nov-04 Sum of 6 PAHS (μg/kg) p.s I. Cíes Aguiño Fisterra Guide value Goose barnacle- Pollicipes cornucopia Figure 3. Evolution of the sum of 6 PAHs in Goose barnacle Razor shell- Ensis ensis 0 20 40 60 80 100 120 140 160 180 200 220 jan-03 mar-03 apr-03 may-03 jun-03 jul-03 aug-03 sep-03 oct-03 nov-03 dec-03 jan-04 feb-04 mar-04 apr-04 nov-04 Sum 6 PAHs (μg kg-1 d.w.) Aguiño I.Cíes Fisterra Guide value Figure 1. Evolution of the sum of 6 PAHs in razor shell Figure 5. Evolution of the PAH profile in goose barnacle from I.Cíes I.Cíes-0204 0 10 20 30 Phen Ant Fluo Pyr BaA Chrys BeP BbF BkF BaP BghiP dBahA In123cdP I.Cíes-0403 -10 10 30 Phen Ant Fluo Pyr BaA Chrys BeP BbF BkF BaP BghiP dBahA In123cdP I. Cíes-0103 0 10 20 30 Phen Ant Fluo Pyr BaA Chrys BeP BbF BkF BaP BghiP dBahA In123cdP EVOLUTION OF THE PAH CONTENT IN COMMERCIAL SHELLFISH FROM GALICIA (NW SPAIN) AFTER THE PRESTIGE OIL SPILL Lucía Viñas, Ángeles Franco, José-Antonio Soriano, Inmaculada Alves, Jessica Bargiela and Juan-José González. Programa de Contaminación Marina. Centro Oceanográfico de Vigo. Cabo Estay-Canido. Vigo 36205. Spain. [email protected] ABSTRACT CM 2005/S:21 From January 2003, just two months after the Prestige accident (November 2002), commercial shellfish samples from different areas affected by the spill were collected monthly. These samples were extracted with a Soxhlet apparatus using a mixture of organic solvents and cleaned up by column chromatography using deactivated alumina and finally analysed for 13 individual PAHs using HPLC-FLD. AESA (Spanish Agency for Food Security) has established a guide value for the sum of 6 of these PAHs and no extraction or commercialization of shellfish could be done over this limit. The PAH concentrations found were compared with that guide value and this was only exceeded in some sites during the first samplings and reached normal values during the summer 2003.The sum of 13 PAHs found in these commercial shellfish species were compared with those found in wild mussels from the same samplings and a similar behaviour was observed for all of them. ANALYTICAL METHODS In these samples, 13 polycyclic aromatic hydrocarbon (PAHs) were determined according to the methodology usually applied in our laboratory (Viñas, 2002). This method is based in a Soxhlet extraction with an organic solvents mixture, followed by an extract cleaning up using column chromatography. Finally, the extract was analysed using high performance liquid chromatography, with wavelength- programmable fluorescence detector. The PAHs determined were: Phenanthrene(Phen), Anthracene (Ant), Fluoranthene(Fluo), Pyrene (Pyr), Benzo[a]anthracene (BaA), Chrysene (Chrys), Benzo[e]pyrene (BeP), Benzo[b]fluoranthene (BbF), Benzo[k]fluoranthene (BkF), Benzo[a]pyrene (BaP), Benzo[g,h,i]perylene (BghiP), Dibenzo[a,h]anthracene (dBahA) and Indeno[1,2,3-c,d]pyrene (In123cdP). This methodology is systematically contrasted by participating in international intercalibration exercises in a regular basis such as QUASIMEME (Quality Assurance of Information for Marine Environmental Monitoring). RESULTS AND DISCUSSION Due to this oil spill, a limit for the extraction and consumption of the different commercial species was established by the AESA (Agencia de Seguridad Alimentaria), fixing the value of 200 μg/kg dry weight, in the case of molluscs and crustaceans, for the sum of 6 PAHs: BaA, BbF, BkF, BaP, dBahA and In123cdP. As it can be seen in figures 1, 2 and 3 this limit was only exceeded for purple sea urchin from I. Cíes in February 2003 and for goose barnacle from Aguiño in April 2003 (first sample available from this area). These concentrations quickly go down reaching what can be considered “normal” values before or during the summer 2003(Σ6PAHs= 2-9 μg/kg d.w.). This study was extended to November 2004 observing some small increases in razor shell during the November- December 2003 period, not clearly observed in the other commercial species, probably due to the different habitat in the same area. In figure 4 the sum of the 13 analysed PAHs is represented for wild mussel as this is a non commercial species and the human health limits cannot be applied. In this case the higher values are again reached in the first months after the spill, reaching normal values during May-June 2003. Some small increases are also observed during the winter period November 2003-January 2004 probably due to some remobilization of the fuel during these months usual heavy weather. CONCLUSIONS • The highest concentrations in PAHs in the four studied species were reached during the first months after the spill. • The values exceeded the AESA limit in purple sea urchin from I.Cíes in January 2003 and goose barnacle from Aguiño in April 2003. • The concentrations reached what can be considered “normal” values during the spring-summer 2003. • Some small increases in razor shell and wild mussel were detected during the winter period 2003- 04 due to some remobilization of the fuel. REFERENCES • Viñas Diéguez, L. (2002) Tesis doctoral: Evaluación de Hidrocarburos Aromáticos Policíclicos (HAPs) por Cromatografía Líquida de Alta Eficacia (CLAE) en el Entorno Marino Gallego. Universidad de Vigo • AESA (Agencia Española de Seguridad Alimentaria) (2003). Medidas adoptadas, en materia de seguridad alimentaria, ante el vertido del Prestige. • Soriano, J.A., M.A. Franco, L. Viñas, B. Cambeiro y J.J. González. 2004(a). Polycyclic aromatic hydrocarbons (PAHs) in mussels from Galician coast (NW Spain) after the oil spill produced by the tanker Prestige. Abstracts book of the 11th symposium on sample handling for environmental and biological analysis. Baiona 2004 • Soriano, J.A., M.A. Franco, L. Viñas, B. Cambeiro y J.J. González. 2004(b). Datos preliminares de hidrocarburos aromáticos policíclicos (PAHs) en mejillón silvestre de la costa cantábrica (España) después del vertido del Prestige. Cuaderno de comunicaciones del XII Seminario Ibérico de Química Marina, A Coruña 2004. ACKNOWLEDGEMENTS This study was funded by MCYT as one of the Urgent Actions developed after the Prestige Oil Spill and continued with the project VEM 2003-20068-C05-03. The samples were supplied by the Cofradía “San José”, Cangas and Xunta de Galicia. The authors of this study would also like to thank the lab technical staff for the preparation of the samples. ICES Annual Science Conference, Aberdeen, September 2005 0 200 400 600 800 1000 1200 1400 jan03 mar-03 apr-03 may-03 jun-03 jul-03 ag-03 sep-03 oct-03 nov-03 dec-03 jan-04 feb-04 mar-04 apr-04 nov-04 Sum 13 PAHs μg kg-1 d.w . Aguiño I. Cíes Fisterra Wild mussel- Mytilus galloprovincialis Figure 4. Evolution of the sum of 13 PAHs in wild mussel A change in the hydrocarbon pattern in the different species is clearly observed when PAH levels fell to a “normal” situation (Figure 5). During the first months after the spill, Chrys and BeP were the most abundant PAHs and as the levels fall Phen and Fluo recover their ususal prevalence. Were previous data were available this change in the profile was also observed (Soriano 2004a, Soriano 2004 b).
