Florida's reefs battered by man, nature

Sanctuary scientists are also trying to assess what impact Hurricane Georges had on the reef ecosystems

November 20, 1998
Web posted at: 2:30 PM EST

By Environmental News Network staff

(ENN) -- The folks down at the Florida Keys National Marine Sanctuary are very busy at the moment, conducting scoping meetings on a no-take area in the Tortugas and trying to assess what kind of damage Hurricane Georges wreaked when it passed through in September.

The reef system in the Keys has been suffering from two manmade problems -- overfishing and pollution. To combat the problems brought on by overfishing, the sanctuary has devised a plan, known as Tortugas 2000, to establish a no-take zone. In July 1997, NOAA created several no-take zones in an attempt to determine whether nature can replenish itself in a small section of the sanctuary. Nothing can be removed -- neither plant nor animal -- within a no-take zone, although divers are still free to dive.

The results thus far have been extremely promising. The fish are getting bigger, the ocean floor is relatively uncluttered and various forms of sea life are reaching breeding age. Scoping meetings, in which public comment was sought on where the sanctuary borders should be, were fairly well attended and the input provided by divers and fishermen was extremely useful, said David Holtz, manager of the Center for Marine Conservation's Florida Keys program.

In addition to the manmade problems, sanctuary scientists are also trying to assess what impact Hurricane Georges had on the reef ecosystems.

"No-take zones are something humans can do when it comes to safeguarding coral reefs, and most of the damage they suffer is the result of human activities. Something that can't be controlled however, is the tremendous power of nature," said Allison Matley, public outreach coordinator for the sanctuary.

"As with most things in life, the scientists are reporting that the storm's impact is mixed; in some areas it helped, and in some areas huge coral heads were tumbled and broken," Matley said as she returned from a technical meeting on the subject.

The hurricane's 90-115 mph winds and seven- to nine-foot storm surge swept through the Western Sambos Ecological Reserve near Key West. In its path, Georges left broken and toppled sea fans and elkorn corals that are now scattered throughout Sambos at depths of seven to 25 feet. Throughout the lower Keys reefs, massive amounts of sediment and rubble were cleared from grooves between the coral spurs and deposited on the reef flat and back reef areas.

Weed racks that had built up along the eastern shorelines of some of the islands were completely washed ashore. While this flushing effect might not make homeowners happy, it's good for the reefs, Matley pointed out.

Several of the scientists lost monitoring equipment that had been moored in the sea for several years. Georges also blasted off black band disease that threatened thriving colonies in some areas of the reef.

"Most of the benthic macroalgae were gone, giving reefs in the lower Keys a clean appearance not seen in years," said David Holtz, manager of the Center for Marine Conservation's Florida Keys program. "Also missing were many elkhorn corals, sponges and urchins -- broken or swept away by the raw power of a storm surge that bent 18-inch steel I-beams."

The Keys have also suffered back-to-back coral bleaching events. Matley says 90 percent of the coral survived last year. However, the stress of continued and serious water pollution problems and the destruction wrought by the storm, have put sanctuary researchers in a wait and see mode. Water temperatures, which trigger bleaching events, are back down, and while that's good news it's just too early to tell what the mortality for this year will be, said Matley.

"Hurricane damage to coral reefs is natural," said Holtz. "What we need to do is assure that human activity doesn't compromise the long-term health of the Keys reefs."

Immediate steps that can be taken to do this, he said, are implementing the Florida Keys Water Quality Protection Program and establishing a 'no-take' marine reserve at the Dry Tortugas.

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