Red Tide Effect on Key's Coral Reefs

From Keynews.com:

Majority of Keys reef is dead, according to scientists

BY TIMOTHY O'HARA

Free Press Staff

May 15, 2008

Humans, dolphins and manatees are not the only ones who have trouble breathing during severe red tide outbreaks. Preliminary data shows that red tides harm coral respiration as well.

Research scientists from the Smithsonian Institution and the University of North Florida dove the reef last week, collecting coral samples and trying to measure how toxic algal blooms affect coral larvae.

Keys fishermen now regularly spot and report red tides from August through January. The poisonous tides are most extensive in Florida Bay and the Gulf of Mexico, but algal blooms with high concentrations of a toxin called Karenia brevis have made their way to the Keys offshore waters.

The scientists collected football-sized mustard hill coral from beneath the Spanish Channel Bridge in Big Pine Key and transported them to the Mote Marine Laboratory in Summerland Key. There, using sophisticated equipment and tools, they measure how red tide — which creates a potent neurotoxin called brevetoxin — affects coral and coral larvae.

Studying the larvae is not easy.

Research scientist Valerie Paul, director of the Smithsonian's Marine Station in Fort Pierce, and her colleagues have to safely collect the larvae, which are the size of a pinhead, in clusters of 300 to 2,000. Once in the lab, they place the larvae in small, water-filled plastic buckets, some of which contain the Karenia brevis toxin.

By comparing the metabolism and oxygen intake of larvae exposed to the toxin with larvae in the healthy water, Paul and other scientists concluded that red tide slows coral metabolism and respiration.

The coral, which produces larvae this time of year, were returned to the channel and reattached to the bridge.

"We don't exactly know what it means, but it shows they're stressed," Paul said.

Worse yet, red tide "may depress coral settlement," said Paul and Cliff Ross, a fellow scientist and assistant professor at the UNF. The rate of coral settlement means life and death for coral species in the Keys, where coral competes for a niche with algae.

Algae, unfortunately appears to be winning the battle. Algae has increased as the number of spiny urchins and other grazing marine animals have decreased. The Keys have seen a 35 percent decline in coral cover since 1996, and some experts estimate that nearly 90 percent of the reef in the Keys is dead.

"It (red tide) not only degrades the process of recovery, but it impacts habitat and water quality," Paul said.

"I think this type of research is critical, so we can fix it," he said. "I don't think people realize how complex coral reef ecology is. There are so many interconnections, making recovery so challenging. It's not simple. Reefs are complex. The problems we are seeing in Florida, people all over the world are seeing."


tohara@keysnews.com

From Keynoter.com:

May 16, 2008

Florida Trend: Oops, our bad

By Kevin Wadlow, Senior Staff Writer, kwadlow@keynoter.com

Magazine picks up Keys story, posts correction

A leading Florida business publication retracted a Web site headline posted this week that declared that most of the Keys reef has died.

A story headlined “Majority of Keys Reef Is Dead, Scientists Say” ranked as the most-read story on the www.floridatrend .com Web site Friday.

Florida Trend staff changed the headline after scientists and tourism officials challenged its accuracy. The headline now reads “Red Tide Hurts Keys Reef, Scientists Say.”

“The previous headline for this article was inaccurate,” a correction notes.

“It's very important that news reporting is accurate,” said Andy Newman, a marketing spokesman for the Monroe County Tourist Development Council. “When a headline on a story like that is not accurate, it has the potential to do damage.”

Staff with Mote Marine Laboratory, which conducts Keys coral studies, and Newman contacted Florida Trend.

The abbreviated story, picked up from a newspaper, centered on an ongoing research project being conducted by Smithsonian Institution and the University of North Florida to see how toxic red-tide algae blooms affect the reef.

Concerns about the overall heath of reef corals were noted later in the story.

“Everyone is in agreement that the reef is in decline, there's not much doubt about that,” Newman said. “But it's my impression that it's not fair to say a majority of the reefs are dead. I wanted to put [Florida Trend] in touch with the experts.”

Florida Keys National Marine Sanctuary staff said the headline makes a worrisome situation sound worse than it is.

“Not everything can be summarized in a sound bite,” Sanctuary Superintendent Dave Score said. “The underlying truth is far more complex.”

“No one is trying to downplay the fact that corals are in trouble worldwide,” Score said. “But to say [a majority of the Keys reef has died] is a misrepresentation of what's happening here.”

The extent of the most spectacular branching corals, elkhorn and staghorn, has been cut by more than 90 percent throughout the Caribbean, Score said.

Coral cover - a metric that assesses the amount of ocean bottom covered by living coral - has significantly declined in the Keys over last decade. Whether the losses approaches 50 percent is a matter of scientific uncertainty.

“We've got to pay attention to the situation and work toward a recovery,” Score said. “But all hope is not lost. There is still habitat out there.

“The system has changed over the last 30 years or so but the coral has been replaced by algae and soft corals. There is still life and fish.”

Corals at the Keys' popular spur-and-groove reefs actually account for “a small percentage” of the corals in the Keys, Score said.