Mosquito Lagoon Oyster Habitat
Jun 26th 2009EdgewaterMosquito Lagoon Oyster Habitat
CANAVERAL NATIONAL SEASHORE — Centuries ago, American Indians piled oyster shells into mounds to form high ground. The shells later served as beds for some of the region’s earliest roads.
Today, plastic mats lay the foundation for an oyster-reef revival in northern Mosquito Lagoon.
Wakes, pollution and overharvesting left the reefs here a shell of their former health.
But after almost three years in the water, the oyster mats that University of Central Florida biologist Linda Walters conceived and volunteers weave are now indistinguishable from nearby natural reefs. These zip-tied habitats have yielded unexpected results, including new seagrass beds and more than 315,000 new oysters.
“Just the water-filtering capacity we have added here is huge,” Walters said, as she stood knee-deep next to one of her mat reefs, where adult oysters clean up to two gallons per hour. That’s 15 million gallons per day from the new oysters.
Walters and other reef revivers hope Walters’ vision can win $4.2 million in federal stimulus funds to place the mats elsewhere. The Nature Conservancy applied for the money through the National Oceanic and Atmospheric Administration to expand the oyster-mat restoration project to Jacksonville and Ponte Vedra Beach.
“A lot of other people are talking to us,” Walkers said. “It is a big commitment to do all of this. You have to have somebody with the heart to run this.”
Decades of channeling the St. Johns River and Lake Okeechobee into the Indian River Lagoon added too much fresh water at the wrong times, and also muck that helped kill off oysters.
Overharvesting and pollution played a role, too.
But in this remote stretch of Mosquito Lagoon, studies proved boat wakes, more than storms or pollution, eroded the reefs. Near frequently traveled channels, constant wakes also prevent free-floating oyster larvae from attaching to the reefs.
Oyster reproduction here is all about getting the “spats” to the mats.
Biologists say the empty shells put out chemical cues that trigger oyster larvae to attach. The tiny ones that do, just a few centimeters long, are called “spats.”
Walters’ mats now number at least 10,000. They provide a shell foundation for 29 reefs that restored about an acre each of oysters, seagrass and other habitats.
Volunteers on land make the mats, each with 36 shells.
Initially, volunteers on water spent hours raking out hardened mounds of shell to create proper elevation for the mats. But this year and last, Volusia County Mosquito Control offered its amphibious excavator to rake the mounds and backhoe shell to a barge.
“We call it the ‘marginator,’ ” said Anne Birch of The Nature Conservancy, major sponsor of the project. “It has transformed the restoration.”
Students, Boy Scouts and even big corporations get in on the oyster-mat action.
This recent day in June — prime “spat” time — Debbie Kelly of Rockledge and Bill Hosch of Merritt Island, both Boeing Co. employees, raked and tied under a sweltering sun. The company already had been involved in latching the mats on land.
“We wanted to see the next step,” Kelly said.
While oyster harvesting is allowed in Canaveral National Seashore, with proper permits, Walters’ reef is off-limits.
“What we’re trying to do with this project is try to restore habitat rather than create oysters for commercial harvesting,” said Troy Rice of St. Johns River Water Management District. “I think it’s been very successful. I could see it working in other areas in the lagoon.”
Rice’s program gave $37,500 to date in federal and license-plate revenue toward the project and has budgeted another $82,500 in plate money for next year. They also await word on a $50,000 state grant.
The $305,000 effort so far — about one a third of it federally funded — is one of many ways scientists and volunteers hope to help eastern oysters regain a foothold in American estuaries. Oyster harvests in the United States declined nearly 99 percent since the late 1800s.
Elsewhere, biologists have tried oyster shells in mesh bags, clamshells, even crunched-up porcelain from old toilets, anything to help larvae take to the reef.
Tampa Bay uses “reef balls,” concrete structures oysters can cling to. Others in Estero Bay use oyster shell in bags to bulk up reefs.
All the efforts seem to be paying off, says Aswani Volety, professor of marine science at Florida Gulf Coast University.
“I’m optimistic. Would we be able to wind the clock the back 100 years? Probably not,” Volety said. “But could we make it much better than it is today? Absolutely.”
Contact Waymer at 242-3663 or jwaymer@floridatoday.com.
http://www.floridatoday.com/article/20090622/NEWS01/906220314
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