Sunday, September 14, 2008

Money is tight, but the Florida Keys National Marine Sanctuary is pushing to begin restoration of Florida Bay's sponge population, devastated in last summer's intense central bay algae bloom.

"It's a very high priority," sanctuary scientist Scott Donohue said. "I am hoping that we can at least have a plan in place and money identified by Oct. 1."

Scientists called the blue-green bloom the worst to rock the critical Everglades estuary since the early 1990s. In its wake, the dark pea-green water virtually wiped out the sponge community in a 25-square-mile area.

Sponges serve several functions in Florida Bay, including providing shelter for juvenile lobster and nurturing juvenile shrimp that live inside their internal organs. They also feed on algae plankton, and as such play a key role in keeping algae growth, the source of blooms, in check.

The marine sanctuary organized a multi-agency meeting of scientists to search for answers to recurring Florida Bay blooms. It was then that sanctuary officials, along with their Everglades National Park counterparts, decided that sponge restoration needed to be a priority.

"We understand the need for the biological services that we lost with the sponges," Donohue said.

The first step in the restoration work could be a small project led by Dr. Mark Butler, a marine ecologist who has monitored sponge life off the Florida Keys for 25 years.

Sanctuary officials, Butler said, have told him that for now, they have about $25,000 to spend. As Butler points out, that's less than the price of many cars. It is not a lot of money to restore 25 square miles of sponge die-off. In fact, Butler said what $25,000 can do is not enough to be called restoration. He prefers the term "demonstration project."

In any case, he said, going small is appropriate for now, because there is still much to be learned about the viability of recolonizing the bay with sponges.

The project would focus on six sites on the edges of the region hit by the bloom. For each of those locations, scientists would take 100 existing sponges, some of which are as big as a car tire, and break off about a baseball-sized chunk of them. The chunks, which can regenerate, would be attached to bricks and put in the water where they could grow. Once they outgrew the brick, the sponges would attach to the natural bay bottom substrate, and, scientists hope, within a year or two begin to reproduce.

"Then, if they can have enough sex, their population can improve and they can help repopulate these areas," Butler said. In sponge reproduction, the male discharges semen into the water, some of which eventually catches onto and fertilizes the eggs contained in the female.

Bill Perry, an ecologist at Everglades National Park, said his agency, which has jurisdiction over most of Florida Bay, is behind sponge restoration as well. But he said park officials won't know how much money they have to back the research until at least October, when the next budget cycle begins.

There is also another concern, he said. Scientists still have not determined what triggered the bloom. A similar event would make even a successful sponge restoration useless.

"If you spend even $200,000 and in the next year or two you have another bloom, it wipes it out," Perry said.

rsilk@keysnews.com