Nitrogen Isotopes - analysis, Environmental Monitoring, Liver - enzymology, Seawater - analysis, Feathers - chemistry, Fuel Oils - toxicity, Cytochrome P-450 CYP1A1 - antagonists & inhibitors, Charadriiformes - metabolism, Carbon Isotopes - analysis, Cytochrome P-450 CYP1A1 - analysis, Cytochrome P-450 CYP1A1 - metabolism, Liver - chemistry, Feathers - cytol...