Grand Isle, La. ? Fishermen who spent much of the summer mopping up oil from BP’s disastrous spill got back to work as the fall shrimping season in Louisiana’s coastal waters opened Monday amid anxiety over whether the catch will be tainted by crude and whether anyone will buy it even if it is clean.

Scores of shrimpers headed out at first light, and early reports indicated a plentiful and clean catch. But a new analysis of federal estimates show the optimism may be premature about how much oil remains in the Gulf.

Five Georgia scientists who reviewed the data said Monday that instead of only 26 percent of the oil remaining, as a federal report said earlier this month, it’s actually closer to 80 percent.

White House energy adviser Carol Browner said on morning news shows earlier this month: “More than three-quarters of the oil is gone. The vast majority of the oil is gone.”

The Georgia team said it is a misinterpretation of data to claim that oil that is dissolved or dispersed is gone.