Transplanted 'super clams' thrive, sparking hope of cleansing gunked-up Indian River Lagoon - Florida Today

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In July 2020, the University of Florida and Whitney Labs teamed up for the Indian River Clam Restoration Project to put thousands of baby "super" clams into the Indian River Lagoon behind River Rocks in Rockledge.

 (Photo: MALCOLM DENEMARK/FLORIDA TODAY)

Whatever genes it takes to survive our collective waste, these clams seem to have them. They are, in the words of one researcher, "super clams."

According to some scientists, these bivalve heroes could be a key to helping restore the waters of the Indian River Lagoon and help solve the problem of one of Florida's worst man-made environmental messes.

We provide plenty of sewage, fertilizer and runoff that fuels algae for them to wolf down. And these tough clams do. Despite recent dips in the lagoon's salt and oxygen levels and thick mats of seafoam, the baby clams recently transplanted from hardy lineages in Mosquito Lagoon to a lab, then to waters near River Rocks restaurant in Suntree, are providing glimmers of hope that the "super clams" could join an army of other filter feeders to help cleanse the ailing estuary.

As the Indian River Lagoon waters morphed over the decades from crystal clear to pea-soup green, then dark brown and foamy this fall, these clams didn't flinch much under the algae overload. And that's got the lead researcher who discovered their abilities as happy as a, well, clam.

"They don't seem to be having any trouble with that, and that's amazing," said Todd Osborne, associate professor of biogeochemistry at the University of Florida's Whitney Laboratory for Marine Bioscience in St. Augustine. "Throughout that process of green water, we've had no issues with our clams." 

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In July 2020, the University of Florida and Whitney Labs teamed up for the Indian River Clam Restoration Project to put thousands of baby "super" clams into the Indian River Lagoon behind River Rocks in Rockledge.

 (Photo: MALCOLM DENEMARK/FLORIDA TODAY)

Even with the recent fish kills and foamy algae breakdown that Osbourne thought might claim all his clams, they held strong.

The clams' survival so far hearkens back to an original hypothesis: People kept telling Osborne he'd never find any live clams in the lagoon. But if he did, he thought, "they will have survived the most obnoxious conditions known to us," making them the fittest clams left in the lagoon. 

"That's the proof in the pudding," Osbourne said. "That's a really positive thing, that the theory worked."

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In July 2020, the University of Florida and Whitney Labs teamed up for the Indian River Clam Restoration Project to put thousands of baby "super" clams into the Indian River Lagoon behind River Rocks in Rockledge.

 (Photo: MALCOLM DENEMARK/FLORIDA TODAY)

Osbourne had searched far and wide in the lagoon for clams with the genetic "right stuff" to survive the estuary's harsher conditions along the Space Coast — made harsher by decades of overfertilizing, leaky septic tanks, sewer systems and stormwater runoff.

He searched throughout the 156-mile-long estuary for any surviving clams until finally striking shellfish gold about a year-and-a-half ago — one pocket of sturdy clams in southern Mosquito Lagoon, where they harvested 39 palm-sized clams. The clams were about 8 years old. A clam typically lives about 15 years.

They brought the sole survivors to the lab, spawned 40 million larvae, then got the word out, and spawned a grass-roots effort to grow back these fittest of shellfish. Their tough-as-nails ancestors survived it all: toxic algae blooms, powerful hurricanes, rancid sewage spills — you name it.

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In July 2020, the University of Florida and Whitney Labs teamed up for the Indian River Clam Restoration Project to put thousands of baby "super" clams into the Indian River Lagoon behind River Rocks in Rockledge.

 (Photo: MALCOLM DENEMARK/FLORIDA TODAY)

Then on June 25, Osborne and his colleagues planted thousands of the 1-year-old, inch-long baby clams from their lab in the cove just off River Rocks restaurant in Suntree, where fishermen once leased the lagoon bottom to harvest clams. Harvesting these protected clams won't be allowed, because they're being planted as a water-quality project in hopes of breathing new life into the lagoon.

The researchers hope that if these hardy clams prosper, more like them can be planted in the lagoon, filtering algae and pollutants from the water and helping to restore the estuary to the days when shellfish were plentiful and edible.

Like oysters, clams filter out harmful algae, nitrogen, phosphorus and other excesses. If these little clams can't survive our lagoon onslaughts, no clam likely can. 

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In July 2020, the University of Florida and Whitney Labs teamed up for the Indian River Clam Restoration Project to put thousands of baby "super" clams into the Indian River Lagoon behind River Rocks in Rockledge.

 (Photo: MALCOLM DENEMARK/FLORIDA TODAY)

Most local clammers stopped making a decent living in the lagoon more than three decades ago. Theories vary as to why. Some blamed the economy, others state rules that were too expensive to follow and/or all the new homes, roads and resulting runoff.

But other researchers point more to prolonged periods of extremes: droughts or periods when heavy rains dumping too much fresh water into the lagoon for too long.

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In May of 2016, workers floated a base layer of oyster shells out into Sykes Creel on a kayak. Volunteers working with Brevard Zoo and Brevard County Natural Resources were out in force off of Newfound Harbor Drive on Merritt Island. The group was planting oyster mats seeded with live oysters.

 (Photo: MALCOLM DENEMARK/FLORIDA TODAY)

Oysters also holding their own

Linda Walters, a biologist at the University of Central Florida, said the recent algae blooms could slow the clams' growth but not their chances for survival.

"I'm happy to hear that the clams are surviving," Walters said via email. "I would not be surprised if growth has slowed as the gills clog with microalgae. If that is temporary, it should not have long-term effects on survival."

Walters also has been embarking on shellfish restorations of her own in the lagoon for years. She said the adult oysters on UCF's restored and natural reefs in the lagoon are also doing well.

She and her colleagues set biodegradable oyster mats into the lagoon, hoping new oysters will "recruit" to the reefs via their larvae. 

"Recruitment of new oysters, however, has plummeted, as we have seen with past blooms as well," Walters said.

When algae cell counts reach high-enough densities in the lagoon, oyster recruitment to reefs comes to a halt, her research has found.

Walters also is finding mangroves in Mosquito Lagoon are taking over intertidal oyster reefs due to warmer winters.

"So it is not just local salt marshes transitioning to mangrove stands," she said.

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In July 2020, the University of Florida and Whitney Labs teamed up for the Indian River Clam Restoration Project to put thousands of baby "super" clams into the Indian River Lagoon behind River Rocks in Rockledge.

 (Photo: MALCOLM DENEMARK/FLORIDA TODAY)

Funding for Osbourne's project includes $103,000 from the Indian River Lagoon Council; $67,000 in county tourism dollars; and $45,000 from saltwater fishing groups — Coastal Conservation Association, Fish America and Addictive Fishing TV. 

The so-called Indian River Clam Restoration Project, founded by Blair Wiggins of Addictive Fishing Television, teamed up with the the nonprofit saltwater fishing group Coastal Conservation Association, the Florida Fish and Wildlife Conservation Commission and UF's Whitney Laboratory for Marine Bioscience in August 2018.

The July planting event brought the total at River Rocks to 270,000 clams. Organizers of the project plan to reach 3.4 million clams planted throughout the lagoon this year. They hope to bring many more to the lagoon in coming years, then let the clams do the rest.

"We might increase that population by a factor of 10 every year," Osbourne said, adding that he plans to pursue grants to scale up his clam concept.

"We've proved that we can do it, now we've got to do it big."

Jim Waymer is environment reporter at FLORIDA TODAY. Contact Waymer at 321-242-3663 or jwaymer@floridatoday.com, on Twitter: @JWayEnviro, and on Facebook: www.facebook.com/jim.waymer

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