Guardian: Late last Saturday afternoon, the helicopter reeled around for one last low sweep over the wetlands in the Mississippi delta. That was when Melanie Bell, normally a manager for BP’s North American gas business in Houston, spotted a small oily sheen on the water. It was approaching a narrow stretch of beach at the end of a spit at South Point, near where the Mississippi river meets the Gulf of Mexico. Oil from the Deepwater Horizon disaster had finally hit land. On Monday, BP’s staging …