William Mahan bends over a bowl of raw shrimp and inhales deeply, using his left hand to wave the scent up toward his nose. Deep breath. Exhale. Repeat. He clears his palate with a bowl of freshly cut watermelon before moving on to raw oysters. Deep breath. Exhale. Repeat.

He’s one of about 40 inspectors trained recently at a federal fisheries lab in Pascagoula, Miss., to sniff out seafood tainted by oil in the Gulf of Mexico and make sure the product reaching consumers is safe to eat.

Oh god help us.