Christian Science Monitor: John Barrios sighs wearily after a full morning of shrimping in his 16-foot aluminum boat. His reddish-brown skin bears witness to a lifetime under a beating sun: He started drawing catch from these waters off a skiff in the 1930s. He's tired, there are too few shrimp, and prices are so low that going out each day seems almost futile. "My time is up," he says. Like many in southwestern Louisiana whose lives revolve around harvest seasons in the Gulf of Mexico, Mr. Barrios turned to oil giant...