Crude oil spread through fragile US marshlands on Thursday, a month after a drilling rig blast released a devastating spill that now threatens Florida, Cuba and even beyond.
Oil has been pouring into the Gulf of Mexico since the massive April 20 explosion on the BP-leased Deepwater Horizon rig that killed 11 and ruptured an underwater well pipe.
While British Petroleum said on Thursday that a tube was now siphoning away 3,000 barrels of oil a day from the leak, a nightmare scene was unfolding in Louisiana wetlands.
"The day that we have all been fearing is upon us today," Louisiana Governor Bobby Jindal said Wednesday after seeing thick oil washing into the state's coastal marshlands.
Crude is also being dragged towards Florida's popular tourist beaches and fragile coral reefs, by an oceanic current that could wash oil ashore on the state's coastline in as little as six days, before carrying it up the US East Coast and even into the Gulf Stream.
The grim picture produced rare cooperation between the United States and Cuba as diplomats from the two nations discussed potential risks, as well as the cause of the spill and its projected movement.
Oil in the so-called Loop Current could cause tremendous damage to a wide range of marine life, experts warned.
"The Loop Current is a super-highway carrying babies of a wide array of fishes and other kinds of marine life from their spawning zones to the places where they will ultimately grow up," Environmental Defense Fund chief ocean scientist Doug Rader told AFP.
In Louisiana, the damage was already being seen, with Jindal telling reporters that "heavy oil" had entered the marshlands. "It's already here, but we know more is coming."
Louisiana biologists said they had rescued an endangered Kemp's Ridley sea turtle whose exterior was heavily oiled, the first found so far. Oil samples from the turtle, rescued on Tuesday, were being analyzed to determine whether they came from the spill, officials said.
South of Venice, the seaport where BP has established its response headquarters, oil was seeping into the marshes at a rapid pace.
Shiny tar balls were caught in thickets of reeds where crabs swarmed about, their shells painted orange by the crude. In some spots, a thick blanket of oil hung at the bottom of the marsh.
Earlier, European Space Agency satellites showed oil being pulled into the powerful clockwise-moving Loop Current that joins the Gulf Stream, the northern hemisphere's most important ocean current system.
The National Oceanic and Atmospheric Administration, the main US agency monitoring the spill, agreed that a small portion of the slick had entered the current "in the form of light to very light sheens."
But it tried to temper fears, saying the oil may never reach Florida and if it does, it "would be highly weathered" with evaporation and chemical dispersants having "significantly" reduced the volume.
Rader warned it was "inevitable" that the cocktail of oil and chemical dispersants would eventually make it to Florida, washing up on beaches on the southeastern US coast.
Cuba's southwestern coast, home to major coral and mangrove systems, as well as a nursery area that supports much of western Caribbean marine wildlife, is also at threat.
BP, which is continuing its efforts to siphon up as much of the oil as possible via a mile-long suction tube, said Thursday it was recovering some 3,000 barrels of crude a day.
The firm estimates that some 5,000 barrels, or 210,000 gallons, a day of crude is spewing from the wreckage of the Deepwater Horizon rig, although independent experts warn the flow rate could be at least 10 times higher.
BP, which has claimed the environmental impact of the spill would be "very modest", agreed Wednesday to a US lawmaker's demand for a live video feed of the oil leak, which could help scientists better assess the flow's rate.
BP hopes to stop the noxious flow with a so-called "top kill" operation in about a week, in which heavy drilling fluids would be injected into the well to stem the oil flow, followed by a cement operation to seal it up permanently.
With concerns mounting over lax federal oversight of the offshore oil drilling industry, top US Senate Democrats urged President Barack Obama to order "immediate and enhanced inspections" of drilling in US waters.
"As the Gulf Coast continues to be threatened by the lasting effects of the Deepwater Horizon oil spill disaster, we are deeply concerned that this accident could be repeated elsewhere," they wrote to Obama.