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Aside from the physical effects of oiling (e.g., hypothermia, dehydration, emaciation), chronic toxicity of polycyclic aromatic hydrocarbons (PAHs) contamination is an important factor influencing long-term recovery of oiled sea birds following an oil spill. Monitoring PAH exposure can help identify populations at risk from toxic effects of PAHs for further study and/or protection. This is the first study to quantify PAH and metabolite tissue burdens in sea birds directly oiled following oil spills. PAHs and hydroxylated PAHs were quantified in liver samples from oiled Common Guillemots (Uria aalge) stranded along the East Coast of England using gas chromatography-mass spectroscopy (GC-MS). Mean parent and metabolite PAH concentrations were 0.25 ± 0.09 (range 0.04–0.97) and 0.52 ± 0.14 (range 0.05–1.48) μg/g (wet wt.), respectively. The main source of PAH exposure was via ingestion of crude oil during preening, resulting in PAH uptake and tissue contamination beyond levels expected from exposure via the food chain. PAN composition corresponded with number of benzene rings in each compound and was typical of contamination from petrogenic sources; pentacyclic < tri- and tetracyclic < tricyclic < dicyclic PAHs.The occurrence of PAH metabolites detected in liver samples also provided evidence of the presence and stereoselectivity of hepatic microsomal CYP1A1 in common guillemots. [ABSTRACT FROM AUTHOR]

Aquatic birds are commonly affected by oil spills. Despite rehabilitation efforts, the majority of rehabilitated common guillemots (Uria aalge) do not survive, whereas mute swans (Cygnus olor) tend to have higher postrelease survival. Polyaromatic hydrocarbons (PAHs) present in crude oil and diesel are immunotoxic in birds affecting cell-mediated responses to immunogens. Because it is a target of PAH toxicity, T-lymphocyte response to controlled mitogen administration (phytohemagglutinnin test) was investigated in a scoping study as a potentially useful minimally invasive in vivo test of cell-mediated immunity. The test was performed on 69 mute swans and 31 common guillemots stranded on the Norfolk and Lincolnshire coastline and inland waterways in England (UK) either due to injury or to contamination with crude or diesel oil. T-lymphocyte response was significantly decreased in swans with greater oil scores. T-lymphocyte responses were also decreased in guillemots, but this finding was not statistically significant.