A cap installed by BP on Friday meant to stop the massive oil gusher in the Gulf of Mexico is capturing less than one-tenth of the oil leaking from the well.

The efforts mark six weeks of failure by the British oil giant to contain what is now the worst spill in American history and one of the biggest environmental disasters of modern times.

The company has estimated that even with the cap, oil may continue flowing into the Gulf until August.

The forecasts come as over 30 percent of the Gulf still remains closed for fishing and oil continues to reach farther down the Florida panhandle.

President Obama, who made his third visit to the Gulf Coast on Friday, told BP sternly that they have "moral and legal obligations" to the people in the region, and warned the company against "nickel-and-diming" fishermen and small businesses while paying large dividends to shareholders and running expensive television ads.

"They say they want to make it right -- that's part of their advertising campaign," Obama said. "Well, we want them to make it right."

Meanwhile, fishermen in the region have reported health problems due to the oil fumes, and say that BP is not providing them with the necessary safety gear to continue their work.

According to the National Wildlife Federation, some 150 threatened sea turtles and over 300 seabirds have died from the oil. Among the birds are Louisiana brown pelicans, which were only recently taken on the endangered list.

Some have accused BP of moving the dead animals from the coast before they can be counted.

Other environmentalists have warned that damage to wildlife in the region could potentially reach the level of extinction.

"You could potentially lose whole species, have extinction events," Michael Blum, a Tulane ecology professor told Inter Press Service. "Brown pelicans were just taken off the endangered species list. On this threshold, a big dieback and mortality event, they would be pushed back into a situation where they could be endangered."

In an opinion piece on Thursday, Sojourners CEO the Rev. Jim Wallis called the oil spill a "teachable moment" that we had better learn the right lessons from.

"Theologically, we are witnessing a massive despoiling of God's creation," Wallis writes. "We were meant to be stewards of the Gulf of Mexico, the wetlands that protect and spawn life, the islands and beaches, and all of God's creatures who inhabit the marine world. But instead, we are watching the destruction of all that."

"Why? Because of the greed for profits; because of deception and lies; because of both private and public irresponsibility," he continues. "And at the root, because of an ethic of endless economic growth, fueled by carbon-based fossil fuels, that is ultimately unsustainable and unstable."

"Almost everyone now apparently agrees with the new direction of a 'clean energy economy.' And we know that will require a re-wiring of the energy grid (which many hope BP will have no part in)," Wallis says. "But it will also require a re-wiring of ourselves - our demands, requirements, and insatiable desires. Our oil addiction has led us to environmental destruction, endless wars, and the sacrifice of young lives, and it has put our very souls in jeopardy."

"There is not one answer to this calamity; there are many: corporate responsibility, for a change; serious government regulation, for a change; public accountability, for a change; and real civic mobilization to protect the endangered waters, coasts, species, and people's livelihoods," he continues. "But at a deeper level, we literally need a conversion of our habits of the heart, our energy sources, and our lifestyle choices. And somebody will need to lead the way."

"Who will dare to say that an economy of endless growth must be confronted and converted to an economy of sustainability, to what the Bible calls stewardship. What about the community of faith?"