When Hooper-Bui went back to the marshes after the storm, she had a surprise waiting for her.
"We discovered in Bay Batiste large amounts of what looked like somebody had poured motor oil all over the marsh there," she said. "About three-quarters of the perimeter of northern Bay Batiste was covered in this oil."
The chemical fingerprint of the oil matched the oil from the ruptured BP well, Hooper-Bui said. Other scientists confirmed that Isaac kicked up tar balls from the spill as far east as the Alabama-Florida state line, more than 100 miles from where the storm made its initial landfall.
Far from the shoreline, patches of oil fell to the bottom of the Gulf in a mix of sediment, dead plankton and hydrocarbons dubbed "marine snow." It fouled corals near the wellhead, and it's still sitting there.
"If you took a picture of a core (sample) that was collected today and took a picture of a core that was taken in September 2010, they look the same," University of Georgia oceanographer Samantha Joye said.
"What's really strange to me is, the material is not degrading," Joye added. "There's something about this stuff, the carbon in these layers, that's not degrading."
Normally, microbes go to work on free-floating hydrocarbons almost immediately, digesting the compounds. The controversial large-scale use of chemical dispersants was supposed to accelerate that process by breaking up the oil into smaller droplets that could be more easily consumed.
But that's not happening to this layer, Joye said, and the reason is unclear.
"The first thing everyone asks is, 'Do you think it's dispersants?' And I can honestly tell you, we don't know," she said.
During the spill, scientists warned that fish eggs and larvae, shrimp, coral and oysters were potentially most at risk from the use of dispersants. The Environmental Protection Agency later reported that testing found the combination of oil and dispersants to be no more toxic than the oil alone.
But that's no comfort to Encalade, who could watch planes spray dispersant on the slick from the marina where he keeps his two boats.
"We know from history, whenever you put soap in the water around camps and stuff like that, oysters don't reproduce," he said. "And we've heard BP say over and over again, 'Oh, it's like detergent.' That's the worst thing in the world you can do to an oyster."
The impact of these dispersants on marine life is still an open question, and it's something that's under review by scientists involved in the Natural Resource Damage Assessment, the federally run, BP-funded effort to figure out what the spill did to the Gulf Coast.
That assessment could take several years.
As scientists sort out the data, the Gulf fishing communities from Louisiana to Florida are still dealing with the impact of the spill. When you look at the entire expanse of the ocean, there isn't a huge amount of oil, explained Ian MacDonald, an oceanographer at Florida State University.
"You have to look hard to find any oil at all," he said.
But where the oil has been found, MacDonald said, the damage is "intense and widespread."
There is some good news: Some studies indicate that commercial fish species in different parts of the Gulf escaped the worst. Recent research at Alabama's Dauphin Island Sea Lab found that young shrimp and blue crabs off Bayou La Batre, the state's major seafood port, showed no sign of decline since the spill.
But that's no consolation for Donny Waters, a Pensacola, Florida, fisherman who has been involved with efforts to rebuild the red snapper populations off the Florida panhandle.
"I'm still catching fish. I'm not saying everything's dead," Waters said. "But it's taking me longer to catch my fish. I'm not seeing the snappers farther around reefs, whether they're natural or artificial. I'm not seeing the reefs repopulate nearly as fast since the oil spill."
'BP has retired me'
Like many in the trade, Encalade and the other guys on his dock in Pointe a la Hache can spin epic tales. But these days, they're not about the catch. More often, they're about the red tape and low-ball offers they've had to deal with in the compensation process set up after the spill -- a process they say is stacked in favor of big operators.
"I got guys been fishing out here all their life. They've got trip tickets, more than you can imagine," Encalade said, referring to the slips that document a boat's daily catch. "You know what they come back and tell a man his whole life is worth? $40,000."
The oil, the catch and the money: All converge at the big federal courthouse on Poydras Street in New Orleans, where squadrons of lawyers have massed for what promises to be a protracted brawl to figure out how much BP will end up paying for the Deepwater Horizon disaster.
BP says it has shelled out $32 billion for the disaster, including $14 billion for cleanup. It's also spent $300 million on everything from testing seafood to its ad campaign that encourages people to come back to the Gulf, and it pledged $500 million for research into the environmental effects of the disaster.