Most people don’t travel to the Florida Keys hoping to see a sponge.
They explore and enjoy Florida’s coral reef – the third largest barrier reef in the world – looking for colorful corals, sea turtles, sharks or schools of tropical fish. Sponges, in all of their alien-like twists and strange blob-like growths, are usually the overlooked supporting cast.
But take them away, and the whole neighborhood starts to fall apart.
Five years after launching what is believed to be the world’s first large coral reef sponge restoration program, Islamorada-based nonprofit I.CARE is providing these unassuming animals a little more attention.
When the Weekly first covered the program, it was still an experiment. Bobbie Renfro-Price, I.CARE’s director of sponge restoration research development, was trying to answer one basic question: Could reef sponges be restored at scale?
Now, she and her team have an answer.
“We are now in our fifth year of sponge restoration,” said Renfro-Price, who’s lovingly nicknamed “Sponge Bobbie.” “When we last spoke, the program was in the pioneering stages of developing transplanting methods. Now, we have transplanting methods that have an over 70% survival rate at one year.”
More than 2,600 sponges have been transplanted onto Florida’s reef tract, with the help of over 400 recreational scuba divers. The team has also established a sponge nursery with Mote Marine Laboratory, developed long-term monitoring programs and continues to study sponge ecology and disease. Their work has inspired similar efforts as far away as Antigua, Barbuda and the Red Sea.
That success reflects a growing awareness of and appreciation for what sponges do for a reef ecosystem. They are ecological powerhouses that filter seawater, stabilize loose coral rubble so baby corals have somewhere to settle, provide habitat for countless marine animals and even feed endangered Hawksbill sea turtles.
Scientists compare them to everything from the reef’s kidneys or Brita filters to living hotels to the “glue” holding reefs together.
It’s a huge evolution from Renfro-Price’s original thoughts about sponge restoration primarily as a way to help corals.
“We wanted the sponges to help with coral restoration by reducing erosion of barren rock, helping hold the reef together and filtering the water around the reef,” she said.
Then, the ocean changed.
“Major events like Hurricane Irma and the fourth global coral bleaching event showed effects not only on corals, but also on sponge populations,” she said. “This has motivated sponge restoration development for the sake of future sponge biodiversity preservation in addition to the useful roles sponges play on the reef.”
The sponge species I.CARE studies appear to be weathering warming oceans better than many corals. “Our data are currently showing that the sponge species we work with may be more resilient to the detrimental effects of warming oceans at the current temperatures,” Renfro-Price said.
She is quick to add that resilience isn’t immunity. She cautions, “We still must dedicate substantial effort to global reductions of carbon emissions.”
For I.CARE, sponge restoration is one piece of rebuilding the entire reef ecosystem.
“We recognize that the coral reef is a complex, interconnected system,” Renfro-Price said. “The best chance for restoration success is to promote the function of the whole system.”
Every second Thursday, I.CARE and Key Dives host sponge restoration training dives for recreational divers with at least 30 logged dives.
“We are thrilled to have public participation on our program,” Renfro-Price said.
To join, call Key Dives at 305-664-2211 and ask about the I.CARE sponge restoration trips.
