An algae bloom has turned sea water around the Florida Keys into a thick green sludge.
Experts are debating the cause of the problem, the Miami Herald reported. Many environmentalists blame a project to widen the road down the Keys to four lanes from Florida City to Key Largo.
Others believe that the three hurricanes -- Katrina, Rita and Wilma --hat hit the area are responsible, the Herald said. The storms carried phosphate-rich silt into Biscayne Bay and Florida Bay.
The bloom began 10 months ago, a month after Wilma, and now covers about 175 square miles.
While the algae do not appear to be toxic, the bloom could harm marine life by cutting off sunlight from sea grass and sponges, the newspaper said.
"Here we are nearly a year out and bloom appears to be getting worse," said Peter Frezza, a biologist with Audubon of Florida. "It's spreading north into Barnes Sound and Little Card Sound. It's not dissipating. That's why we're becoming so concerned."
While the state has declined to stop the highway work, contractors in the future will remove mangrove trees cut down for the project instead of using them to create a foundation for the roadway.
Copyright 2006 by United Press International
Explore further: US northeast braces for flooding after record snow