The terrible effects of the oil spill in the Gulf of Mexico were becoming clearer nearly seven weeks after an oil rig burst into flames and sank, leaving a broken wellhead gushing crude into the ocean on a scale never before seen in the United States.

Wildlife in the Gulf, including dolphins and sea turtles, continued to wash ashore as images of waterfowl stuck in large pools of toxic, tar-like crude flooded in. Beaches and wetlands were being soiled across a larger swath of the southern coast.

"These waters are my backyard, my life," said Dave Marino, a boat captain, firefighter and fishing guide from Myrtle Grove, Florida. "I don't want to say heartbreaking, because that's been said. It's a nightmare. It looks like it's going to be wave after wave of it and nobody can stop it."

The U.S. Coast Guard announced Saturday that a cap placed over the gushing oil well had collected nearly a million litres of crude in the first full 24 hours it had been in place.

Coast Guard Adm. Thad Allen, the federal government's top official overseeing the response to the spill, told reporters the goal is to get the cap to capture more oil -- its capacity is 2.38 million litres per day.

But that ray of hope was tempered as a yellow stain continued to grow on Pensacola Beach in Florida, which was littered with tar balls as crude-soiled waves rolled to shore.

Erin Tamber moved to the beach after living in New Orleans for 30 years and enduring Hurricane Katrina.

"I feel like I've gone from owning a piece of paradise to owning a toxic waste dump," Tamber told the Associated Press Saturday morning.

Also on Saturday, U.S. President Barack Obama used his weekly radio and Internet address to stand firm with the citizens of the ravaged region.

"We will make sure they pay every single dime owed to the people along the Gulf coast," Obama said of the company responsible for the spill, BP PLC.

BP has failed in every attempt to stem the flow of oil, which has been pouring into the Gulf since April 20, when an oil rig exploded off the coast of Louisiana, killing 11 workers.

Since then, government estimates say between 83 million litres and 178 million litres of oil have spilled into the ocean and continues to wash ashore in Louisiana, Mississippi, Alabama and Florida.

The cap resembles an upside-down funnel that was lowered onto the blown-out well. On Saturday, oil continued to escape through vents designed to prevent ice crystals from forming on the cap. Engineers will attempt to close those vents in the coming days.

It is also unclear if the cap fits the well. Underwater robots had tried to cut the well to provide the cap with a smooth surface to rest on. However, the saw jammed and the robots were unable to make a clean cut.

The oil has ruined sensitive marshland along the coast and covered wildlife in slick crude. Images of oil-covered Brown Pelicans have horrified locals.

"In Revelations it says the water will turn to blood," P.J. Hahn, director of coastal zone management for Louisiana's Plaquemines Parish, told AP. "That's what it looks like out here -- like the Gulf is bleeding. This is going to choke the life out of everything."

"It makes me want to cry," he added.

On Friday, Obama met with local leaders and residents of Grand Isle, La., on his third trip to the region, where he was faced with demands to show more leadership in the containment and clean-up efforts.

"He ain't much of a leader," Eugene Ryman Jr. told AP of Obama. "The beach you can clean up. The marsh you can't. Where's the leadership? I want to hear what's being done. We're going to lose everything."

In his weekly address, Obama talked of people he had met in Louisiana, including an oyster fisherman whose oyster beds were destroyed, as well as a shrimper who cannot work.

"These folks work hard," Obama said. "They meet their responsibilities. But now because of a manmade catastrophe -- one that's not their fault and that's beyond their control -- their lives have been thrown into turmoil."

"It's brutally unfair. It's wrong. And what I told these men and women -- and what I have said since the beginning of this disaster -- is that I'm going to stand with the people of the Gulf Coast until they are made whole."

With files from The Associated Press