HARBOR BRANCH - OFFICIAL PRESS RELEASE

ALIEN INVADER RETURNS - SURVEY FINDS SEAWEED WOES ON REEFS FROM PALM BEACH TO DADE COUNTIES

FT. PIERCE, Fla. -- Aug. 18, 2005 -- During a survey of South Florida coral reefs, a Harbor Branch research team has discovered clumps of harmful, invasive seaweed in areas of Palm Beach County that had been scoured clean of the plague during last year's hurricanes. In Broward and elsewhere, the scientists found up to 70% of some reefs covered by other seaweed species. The team is currently working to superimpose seaweed data onto advanced three-dimensional maps of the state's reefs in order to track future proliferation.

The survey project, funded by the State of Florida, was designed to map and monitor the spread of harmful seaweed at 84 reef sites between Miami and Fort Pierce. Based on ongoing Harbor Branch research, Brian Lapointe, a Harbor Branch marine ecologist who heads the survey group, believes this spread is closely tied to nutrient pollution from land-based sources such as deepwell injection, sewage outfalls, and Okeechobee discharges (for background information, please see: http://www.hboi.edu/marinesci/dynamics.html).

During a first survey in August 2004, researchers found that Caulerapa brachypus var. parvifolia--a particularly damaging strain of invasive seaweed from the Pacific first discovered in Florida waters in May 2001--was covering over 60% of some Palm Beach reefs. Later, however, the team found that violent seas and currents stemming from hurricanes Frances and Jeanne had largely removed the menace.

During their second survey, completed in July, the researchers once again found pockets of C. brachypus emerging at a number of deeper reef sites on Palm Beach County reefs between the Lake Worth and Jupiter Inlets. Only small amounts have been spotted, but, says Lapointe, "We know from past experience that it doesn't take much; this stuff can come back very quickly." Researchers also found that a related species native to Florida that in large amounts also poses threats to reefs, called Caulerpa racemosa, is prevalent on Broward and Palm Beach County reefs near inlets.

During the survey, the team found that many of the Palm Beach, Martin, and St. Lucie County reefs are still covered in sand from the 2004 hurricanes, which Lapointe says may slow the spread of the harmful seaweeds in those areas.

In Dade, Broward, and southern Palm Beach counties, the team found up to 40% coverage on some reefs by blue-green algae (similar to seaweed) such as Lyngbya. At other reefs, the researchers found up to 70% coverage by Dictyota and other seaweeds. Healthy reefs would only have only traces of these species.

"These blooms are definitely a serious problem on Broward reefs," says Lapointe, who found much lower concentrations of troublesome species during work in the area in 2001. "That's obviously a sign that water quality is worsening," he says. Beyond smothering the reefs and associated inhabitants, Lyngbya could even pose future threats to beachgoers, according to Lapointe, because some species are known to cause dermatitis.

The team is currently processing video of the reefs as well as chemical data collected to help determine what is driving the spread of the seaweed. They are working to integrate all of the information on hand into detailed 3-D maps of the reefs created using Laser Airborne Depth Sounder (LADS) technology. The goal is to better illustrate where blooms are worst in order to spot patterns of human activities and other factors that may explain differences observed, and, over time, to visualize the extent to which the harmful species are spreading. Once completed, this imagery will be made available to the public.

This most recent survey, and the initial survey completed in December of 2004 ( http://www.hboi.edu/news/press/dec2104.html), were funded through a $500,000 appropriation from the State of Florida. The group has also received a second $500,000 appropriation from the state to continue the work for another year.

For more information, please contact Mark Schrope at 772-216-0390 or schrope@hboi.edu. B-roll and high-res photos of the reefs and seaweed are available, as well as examples of the 3-D LADS maps showing reefs and their seaweed and blue-green algae coverage.

HARBOR BRANCH Oceanographic Institution was founded in Ft. Pierce, Fla., in 1971 to support the exploration and conservation of the world's oceans. The institution has held to this mission and grown into one of the world's leading oceanographic institutions with a 500-acre campus, over 200 personnel, and a fleet of sophisticated research ships and submersibles.