Vitellogenin variation in the crab Carcinus maenas exposed to sediments affected by oil spills (Spain)

In the present study the induction of vitellogenin has been studied as a biomarker of exposure in crabs in order to assess its relationship with contaminants bound to sediments [Zn, Pb, Cu, Ni, Co, V and polyaromatic hydrocarbons (PAHs)] affected by different oil spills in Spain. Two different 28-days bioassays have been carried out both under field and laboratory conditions by exposing the crab Carcinus maenas to contaminated sediment samples. For the field approach the organisms were labelled and kept in cages located in the study sites during the exposure period. In the experiment conducted under laboratory conditions sediment from the stations was collected and carried to the laboratory where labelled crabs were placed in 20 L tanks with the sediment samples. For both bioassays haemolymph was extracted from the individuals the day 0 and 28 of exposure to determine the variation in the levels of vitellogenin after the bioassay. The Spanish sediments selected for this study had been affected in a different way by oil spills; the Galician Coast (NW Spain) was acutely impacted by the accident of the tanker Prestige (2002) whereas the Bay of Algeciras (South Spain) suffers chronically from continuous input of different contaminants from ships and industries located in the area, including oil spills. Results show a relationship between vitellogenin variation and contaminants. The variation of vitellogenin concentration was related to the presence of PAHs and the metals Pb, Ni and Cu in the sediment, which occurred mainly in the treatments from the Bay of Algeciras. In this sense, the study shows a partial recovery in the sediment quality in the Galician Coast three years after the spill, whereas the Bay of Algeciras is significantly more polluted than the sediments studied in the area of Galicia.