Killer Algae: UCF Scientist Studies Caulerpa taxifolia, an Invasive, Destructive Algae
by Sae Schatz

ORLANDO, Jan. 20, 2004 -- Caulerpa taxifolia, a feathery green alga, may seem innocent enough at first glance, but to biologists-and residents of the Mediterranean, Australian, or Southern Californian coasts-the plant is known as "killer algae."

Caulerpa taxifolia is a naturally occurring, seaweed, which is native to tropical places around the world. However, the aquarium variety of the strain is invasive. Once it is introduced to an ecosystem it spreads rapidly: killing the other plants and destroying habitat for many fish and marine invertebrates. It produces chemicals that are harmful to sea life (although not to humans). The chemicals kill the creatures that eat the Caulerpa taxifolia or drive the animals out of the area.

This was the scenario that occurred in the Mediterranean Sea. In the 1980's an invasive aquarium strain was accidentally released (probably from the Oceanographic Museum in Monaco), and now, twenty years later, the coastal ecosystems of Monaco, France, Italy, Spain, Tunisia, and Crotia have all been negatively impacted.. "The Mediterranean will never come back from this Caulerpa invasion. No corals, no sea grasses, no fish, no shrimp-they lost it all, and it all happened in a 20 year time span," says Dr. Linda J. Walters, a biologist at the University of Central Florida who studies Caulerpa taxifolia.

Dr. Walters, with support from the National Sea Grant, U.S. Dept. of Agriculture, and the Tampa Bay Estuary Program, will examine Caulerpa taxifolia's life-cycle, biological controls of it, and seek out new ways to deal with outbreaks of it. She will also help devise an education/outreach strategy to prevent potential Caulerpa taxifolia invasions of Florida's waters and identify likely invasion hotspots.

In 2000 and 2001 Caulerpa taxifolia outbreaks erupted just north of San Diego, California and in southern Australia. "They used chlorine in California to eradicate the invasive Caulerpa. The chlorine killed the fish," explains Dr. Walters. "It killed everything in that area." In New South Wales, Australia, the Caulerpa containment strategy was even more severe. "They used copper-sulfate in Australia," says Dr. Walters, "which is even nastier than chlorine. We don't want to ever have to do that in Florida."

California and Australia went to such extreme efforts to eradicate the invasive Caulerpa in their areas because of its terrible effects and its resilience to other forms of removal. "When I was working on it in Hawaii we found that fragments as small as your fingernail can grow clonally," recounts Dr. Walters, which means that if even a tiny piece of Caulerpa was missed during the removal process, the entire outbreak could renew itself. "In a day the small fragment will have reattached to the substrate. It will have doubled in size in four days, and then it will just keep growing."

Dr. Walters hopes that native Florida sea slugs may hold the answer to dealing with Caulerpa. She and fellow Caulerpa expert Dr. Jeanine L. Olson of the Netherlands-based University of Groningen will use DNA fingerprinting technologies to compare Caulerpa native to Florida to invasive strains. Caulerpa strains from around the world in order to compare them to the invasive varieties. Together with Dr. Olson, Dr. Walters and her graduate students hope to prevent Caulerpa from ever entering our waters, or if it does, to rapidly identify this invasive strain and eradicate it.

DATE
January 20, 2004

CONTACT
Linda J. Walters
407-823-2148
ljwalter@ucf.edu

DOWNLOADS
(none)

LINKS
Biology Dept.

PHOTOS
Click for enlargement
All sizes given in pixels

Width: 526  Height: 339


Width: 555  Height: 366


Width: 310  Height: 424


Width: 740  Height: 494