Nearing record highs in March, gasoline prices have dropped for most of April across the U.S. and on average are cheaper than they were a year ago. As pump prices ease, federal prosecutors are turning up the heat in the BP oil spill case, arresting an ex-engineer accused of obstructing justice by deleting potentially damaging e-mails. And as the feds begin arrests, local reactions in the Gulf among individuals and businesses harmed by the spill are mixed, with oyster leaseholders “overjoyed” by the BP settlement, while shrimp processors are challenging some features of the deal. While watermen and women digest the settlement, Gulf of Mexico fish near the spill—such as grouper and red snapper—are showing telltale signs of sickness associated