NYT: Extensive testing of Gulf of Mexico seafood by federal scientists has found only minute traces of the dispersant Corexit, which was used to break up oil from the BP spill, officials say. About 1.8 million gallons of dispersant were applied to the waters` surface and at the wellhead, nearly a mile undersea. Associated Press A technician tested a sample of yellowedge grouper as Commerce Secretary Gary Locke looked on last month at a lab in Pascagoula, Miss. Of 1,735 tissue samples analyzed, only…