Rapid screening of shellfish tainting from oil spills using an antibody-based biosensor

Tainting of shellfish by polyaromatic hydrocarbons (PAHs) following an oil spill poses possible health risks as well as socioeconomic impacts. Traditional screening approaches for evaluating PAH contamination have limitations that can prevent timely, objective spill response decisions. The objective of this study was to investigate the relationship between PAH concentrations measured in the oyster, Crassostrea virginica, interstitial fluid using a rapid antibody-based biosensor method, with PAH concentrations in oyster tissues determined using conventional gas chromatography-mass spectrometry analysis. To accomplish this objective, bioconcentration tests were performed to simulate oil spill exposures using a crude and heavy fuel oil containing different PAH compositions. This design allowed both the PAH concentration and composition in water and, subsequently, accumulated by oysters to be varied over time. Oysters sampled during uptake and depuration phases were analyzed using biosensor and conventional analysis methods to generate comparative data. Results indicated that biosensor measurements of oysters captured the kinetics of PAH accumulation during uptake and depuration phases. Further, significant positive correlations were observed between biosensor interstitial fluid and lipid-normalized PAH tissue concentrations. However, quantitative predictions appear to be modulated by the contamination source and target analyte list for tissue analysis. Thus, the biosensor can be applied for rapidly evaluating relative PAH contamination between biota samples and offers a promising new analytical tool for oil spill monitoring and fisheries management contexts. A generic model was also developed from study and literature data to predict PAH half-lives from bivalve tissues. These predictions can help inform field monitoring of shellfish and estimate recovery times required to achieve pre-spill conditions.