An algae bloom poses a serious threat to reefs off South Florida, and scientists are trying to figure out the cause and a solution. Commercial divers say they have seen increasing amounts of green algae in recent weeks on offshore reefs from Deerfield Beach to Jupiter.
South Florida's reefs are part of a tract of underwater formations that extends into the Florida Keys. The reefs are considered a key ingredient in the region's fishing and tourism industry.
The algae can block the sunlight and water circulation that reefs need to survive. But scientists must identify what is triggering the algae blooms before they can find a solution.
Some of the same reefs suffered varying degrees of damage last summer after they were buried under a layer of thick algae, which dissipated as water temperatures cooled during the winter.
"It is a serious problem that will continue to get worse unless something is done," said Brian Lapointe, a scientist with the Fort Pierce-based Harbor Branch Oceanographic Institution.
Several research projects under way or in the planning stages will study the problem.
Scientists from the University of Miami and Florida International University will conduct research in coastal waters along Palm Beach and Broward counties.
Scientists conducting a $1.5-million project for the National Oceanic and Atmospheric Administration also may study the algae if they find it close to six outfall pipes between Miami and Delray Beach. More than 10-billion gallons of treated sewage is emptied through the outfall pipes each month.
"We see a symptom, but we really have no idea what is causing it," said Steve Somerville, an administrator with Broward County's Office of Natural Resource Protection.
Lapointe, who has studied algae blooms throughout the Caribbean and Europe, speculates that phosphorus-laden sewage and agricultural runoff, coupled with warm water temperatures in the summer, may fuel the algae blooms.
But Carman Vare, an analyst with Palm Beach County's Department of Environmental Resource Management, said there are other possible explanations.
"It could simply be a natural cycle in which this happens for a couple years in a row, and then we may not see it again for 50 years," he said.
Or, Vare said, the northward-flowing Gulf Stream could be carrying nutrient-rich waters from the Miami area or somewhere else, sparking algae blooms.