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Coastal cities deploying oyster reef balls to combat rising sea levels

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Posted at 12:38 PM, Dec 17, 2021
and last updated 2021-12-17 16:44:37-05

CHULA VISTA, Calif. — Coastal communities are using nature to clean the ocean and combat rising sea levels. Their secret weapon: oyster shells.

"One of my personal statements is, I joke, I'm trying to save the planet one acre at a time," said Eileen Maher, director of environmental conservation with the Port of San Diego.

Scientists say sea level rise is inevitable, set into motion by emissions released decades ago. But Maher’s team hopes to rewrite the San Diego South Bay’s future.

After years of planning, the installation of the South Bay Native Oyster Living Shoreline Project is underway, adjacent to the Chula Vista Wildlife Refuge. Researchers are utilizing oysters to stabilize shorelines in place of the traditional hard armoring such as rip rap revetment and sea walls.

"Native oysters, when they're establishing a home, they see other oysters and say, that must be a safe place to live. So, they like to attach to existing shells, which helps build a reef," said Maher.

Made up of oyster shells, sand and concrete, the Port is installing 360 reef balls in the San Diego South Bay. Each reef array includes 15 reef groups composed of four reef ball elements.

"Specifically aligned based on standard wind patterns to help prevent the waves from crashing on the shoreline, and they'll crash onto the reefs instead," said Maher.

Researchers believe the project will help increase biodiversity by creating new marine habitats.

According to NOAA, oyster reefs create essential habitats for hundreds of other marine species. Species like mussels, barnacles, and sea anemones settle on them, creating abundant food sources for commercially valuable fish species. They also provide a habitat to forage fish, invertebrates and other shellfish.

Like Mother Nature's own Brita, oysters also help clean the ocean, each one filtering up to 50 gallons of water a day.

"It's actually how they feed," said Maher. "So, drawing in that 50 gallons a day, there are food particles for them."

After installation is complete, the pilot project and the adjacent shoreline will be monitored and assessed for five years. Researchers will be studying the growth of native oysters on the reef elements and learning how the reef impacts or enhances local species.

If successful, Maher hopes the resiliency strategy will gain traction across U.S. coastlines.

Similar projects are already underway in San Francisco, Tampa and New York City.