Coral Killer Spreads
5/25/2004 6:00:18 PM by Susan Cocking
A dark red algae bloom resembling angel's hair that covered some Broward County reefs last summer has not let up this winter, and might be spreading north and south. The filamentous substance has been identified by Boston University microbiology professor Steve Golubic as a type of cyanobacteria called lyngbya confervoides.
Golubic reached that conclusion after testing large samples collected by Broward divers last September. So far, the stuff doesn't seem to be toxic to humans; no one who has handled it has reported any adverse symptoms. But it is killing sponges and soft corals such as sea whips and sea fans at depths ranging from 20 to 70 feet.
"It usually eases off in the winter, but it's not doing that," said Ken Banks, manager of marine resources programs for Broward's Department of Planning and Environmental Protection. "It got cropped down by the weather, but it didn't go away. We went diving [Feb. 2], and there was a rope [Nova University researcher] Dave Gilliam put in the water six weeks ago and it had eight centimeters on it. One of our research projects on coral recruitment is covered with it."
Banks is drafting a map depicting areas where the cyanobacteria growth is heaviest and where there is none. He is asking divers who spot heavy concentrations to e-mail the GPS coordinates (kbanks@broward.org).
Henry Del Campo, owner of H20 Scuba in Sunny Isles Beach, says he has spotted blooms covering natural and artificial reefs from 20 to 60 feet deep extending from the Dade-Broward line south to Government Cut. Recreational diver Ed Tichenor reported gobs of the stuff draped on a popular dive spot off Boynton Beach known as "Lynn's Reef" in 40 to 50 feet of water in 2002. It has since spread to almost the entire three-mile length of the Gulf Stream Reef system that includes Lynn's, according to Tichenor.
Aproliferation of cyanobacteria is a sign of environmental deterioration because the stuff feeds on nutrients in the water. However, Banks said, no one has been able to pinpoint the source. Many factors can contribute to nutrient loads, such as deep-ocean upwellings, improperly treated sewage, urban and agricultural run-off, and contaminated groundwater bubbling up from the ocean floor.
To discover what's causing the bloom, researchers -- including Valerie Paul of the Smithsonian Marine Station in Fort Pierce -have applied for a three-year, $700,000 grant from the EPA, National Oceanic and Atmospheric Administration and National Science Foundation.
"It's going to cover all the reefs in southeast Florida pretty soon," Paul warned. "All algae feed off nutrients in the seawater, so why is this one taking off?"
Susan Cocking can be contacted at scocking@herald.com