On a recent overcast day, University of Florida experts dove into the Gulf, hoping to increase sponge abundance in an area off Hernando Beach.
It’s not a deep dive – about 10 feet. But the hard bottom is key: It’s where sponges live and help other marine organisms – including snapper and stone crabs — survive and hopefully, thrive.
From the bottom of the Gulf, researchers take sponges from one area, cut them into many pieces, zip-tie them to bricks and place them on the bottom to heal and grow in other areas, where sponges are scarce. They initially hope to improve sponge habitats in a 2-square-mile area.
Their goal is to identify appropriate sites and sponge species that are environmentally and commercially valuable to restore or enhance the sponge communities offshore from the Tarpon Springs region, which has a rich history with sponges.
Assuming their transplanted sponges multiply, UF/IFAS experts want to eventually spread their research to an area off the Gulf from Pinellas County to Levy County.
Anglers and sponge fishermen rely on the sponges to make money. The economic and ecological benefits of sponges compel UF/IFAS experts to take the sponge plunge.
Through grants from the National Fish and Wildlife Foundation and Florida Sea Grant, they’ve gone into the water several times in the past year, most recently, on March 18.
That day, they looked at survival of the sponges they had cut and moved, and they saw a high survival rate – about 75% — which bodes well for their small project.
“One of the most important roles they can play is improving water clarity,” said Don Behringer, a UF/IFAS professor of marine and disease ecology and Florida Sea Grant-affiliate faculty. “Through their ability to filter water, they take phytoplankton and other particles out of the water, some of which can harm other marine life. Sponges also form habitat and provide shelter for many species of fish, crabs and other marine life that live in hard bottom.”
Thus far, they’ve found five types of sponges as candidate species to grow – three are valuable ecologically, while the other two are important for ecological and commercial purposes, Behringer said.
UF/IFAS scientists and Brittany Hall-Scharf, a UF/IFAS Extension Florida Sea agent in Hernando County, initially placed about 200 individuals of each species, or about 1,000 total on the floor of the Gulf.
“If we scaled up the project, we would hope more sponges would increase filtration,” Behringer said. “So, you could potentially improve water quality perhaps enhance fisheries for species such as snapper, grouper and stone crabs that use sponge-dominated hard bottom. But you’d have to do more research. You can’t make those determinations at this small, experimental scale.”
The commercial sponge-fishing industry in the Tarpon Springs area supports a robust community of fishers with a strong Greek heritage linked to sponge fishing. Prior research by Behringer and colleagues suggests that commercial sponge fishing can be sustainable if done correctly.
“Sponge fishers are remarkable at identifying and harvesting only commercially valuable sponges,” he said. Additionally, if sponge fishers leave a portion of the harvested sponge attached to the bottom, it will often grow back.
Facts like those make the pilot project worthwhile to Behringer and his team.
“The key to scaling up any habitat restoration or enhancement effort is making sure the foundational research is done prior to ensure success to the greatest degree possible,” he said. “With support from the National Fish and Wildlife Foundation and Florida Sea Grant, we have taken the first step in that direction.”
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ABOUT UF/IFAS
The mission of the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) is to develop knowledge relevant to agricultural, human and natural resources and to make that knowledge available to sustain and enhance the quality of human life. With more than a dozen research facilities, 67 county Extension offices, and award-winning students and faculty in the UF College of Agricultural and Life Sciences, UF/IFAS brings science-based solutions to the state’s agricultural and natural resources industries, and all Florida residents.
ABOUT FLORIDA SEA GRANT
Hosted at the University of Florida (UF), the Florida Sea Grant College Program supports research, education and Extension to enhance coastal resources and economic opportunities through a partnership with the National Oceanic and Atmospheric Administration, the State University System of Florida, and UF/IFAS Extension in counties statewide.
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