"Due to other conditions"

Probably Ebola.  Maybe Mayans.  Are Mayans still a threat?

Gulf Coast oyster harvests have declined dramatically in the four years since a BP PLC oil well blew wild in the nation's worst offshore oil disaster. Even after a modest rebound last year, thousands of acres of oyster beds where oil from the well washed ashore are producing less than a third of their pre-spill harvest.

Most worrisome to Slavich is the dearth of oyster larvae - future generations of oysters - once found in abundance on shells in the lake, east of the muddy bends of the Mississippi River.

Whether the spill contributed to the decline is part of an ongoing study; hurricanes, overfishing and influxes of oyster-killing fresh water had already put pressure on the industry.

"To the extent that oyster populations are down, data from government studies have indicated it is likely due to other conditions," Geoff Morrell, a BP senior vice president, said in a statement.