Several demonstrators gathered outside BP's D.C. offices to protest the company's offshore oil drilling operation.

Three weeks ago, a BP oil rig off the coast of Louisiana was rocked by a massive explosion. Four million gallons of oil has spilled into the Gulf of Mexico since then.

"Everybody is pretty much on pins and needles," said National Geographic photographer Tyrone Turner, who talked to fishermen and others affected by the spill. "There's a fair amount of confusion and anger … the fishing grounds and the oyster beds have been closed … so they are out of business. They can’t do anything."

Turner saw the spill firsthand by boat and by air. The magnitude is hard to comprehend, he said, as is the potential effects on the Gulf’s ecosystem.

"You just see all of this life out there and that’s why everyone is so focused on this to try and stave off what could happen," he said.

On Capitol Hill Tuesday, executives from the companies in charge -- BP, Halliburton and Transocean -- traded blame, with BP sidestepping compensation to harmed communities.

"We are going to pay all legitimate claims," said BP President Lamar McKay.

That’s not good enough, protesters said.

"Our demand is very straightforward, it's very simple: Seize assets of BP sufficient to compensate the people they harm," said Carl Messineo, organizer of the Seize BP campaign.

Turner's going back to Louisiana to document more of the people affected by the spill.

"I was at a training session for fishermen who were learning how to put out the container booms, and the anger was that not all of them got to do it," Turner said. "They all wanted to get out there and do it, and that was a real sense that we don’t want to wait."

