Lake Jesup -- Afflicted by pesticides, sewage, fertilizers and industrial chemicals, Lake Jesup is the most polluted section of the St. Johns. But according to biologist Jim Gelseichter, the stingrays that call it "home" don't seem to mind. Or do they? Jim's latest tests show abnormal changes in their hormone levels. Whether humans are similarly affected is debatable. What's not debatable for Jim is whether he'd eat fish from Lake Jesup. The answer, decidedly, is "no."