BREVARD COUNTY, Fla. – Oysters, once plentiful along the Indian River Lagoon, are key to maintaining a healthy waterway. The Brevard Zoo is making headway in restoring the lagoon's oyster reefs with help from from a half-cent sales tax and many volunteer hours.

The mollusks are natural water filters. Mature oysters can process up to 50 gallons of water in a day. As oysters filter free-floating microscopic algae for food, they clean the water. Oysters, mangroves and seagrasses along the lagoon shore also act as a break line, preventing erosion and filtering out pollutants.

The problem for the Indian River Lagoon is that there simply aren't enough oysters right now, said Ashley Rearden, Brevard Zoo restoration office manager.

The Brevard Zoo, through its Restore Our Shores effort, has partnered with Florida universities, environmental groups, concerned citizens, restaurant owners and waterfront property owners to make headway in restoring the oyster reefs across the 156-mile lagoon.

In 2016, a Brevard County half-cent sales tax was approved to raise $303 million as part of the Save our Lagoon Plan, which funds projects to clean and protect the lagoon from pollution, as well as restore the mangrove and oyster populations on the shorelines.

The zoo's Restore Our Shores team got creative to tackle the problem, putting a call out to waterfront property owners to build new oyster reefs and seeking used oyster shells from restaurants to create reef beds.

[Pictures: Indian River Lagoon]

Using hundreds of volunteers, the zoo bags the shells in nets, creating new layered reefs along waterfront property and placing live oysters on the top bags. Each reef-building field day takes about 40 volunteers and is then maintained by the property owner turned-oyster gardener, Rearden said.

Data collected by the gardeners help zoo restoration experts determine what areas are best for building new oyster reefs. Spat, or oyster larvae, are collected and raised by the zoo until they are mature enough to be planted in a reef.

Rearden said oyster projects funded with Save Our Lagoon taxes cover about 1.3 miles of the lagoon with plans to expand those reefs an additional 2-miles each year with funding approval.

Where did all the oysters go?

Around the world, 85 percent of oyster reefs have been lost, according to The Nature Conservancy. The mollusk population has dramatically declined due to overharvesting, coastal construction, poor water quality, disease and boat wakes.

In Mosquito Lagoon, part of the north end of Indian River Lagoon, boat wakes dislodge oysters from their reefs, pushing them onto islands. The dead oysters then create dam-like walls restricting water flow over other reefs and sea grass.

New techniques developed by groups restoring oyster populations anchor the mollusks to the bottom of the lagoon to withstand boat wakes. Within a year, the reefs can be healthy and attract new oyster larvae. 

Along the rest of the lagoon, it's the water conditions killing off marine life. A brown algae bloom in Cocoa Beach and Merritt Island has been killing seagrass and oysters since 2012.

[RELATED: Red tide and blue-green algae: What's the difference?]

That's why anywhere else along the river, the zoo is using old oyster shells to create new reefs and raising oyster larvae until they are ready to be planted among the reefs.

Since the zoo started its oyster restoration efforts in 2014 more than 352,000 live oysters have been placed in the Indian River Lagoon.

Restore Our Shores put a call out to property owners along the river to build these reefs anywhere they can. When a property owner volunteers, the zoo applies through the Brevard County Natural Resources office for Save Our Lagoon funding, and if the money is approved, volunteers and the restoration team get to work building a new reef.

This season the zoo has about 220 waterfront participants in the oyster gardening program.

What can you do?

Let the zoo take those shucked shells off your hands

The zoo is in need of empty oyster shells to create new reef beds. Several Brevard County restaurants are already donating their used shells to the zoo, but the zoo is looking for more to participate.

Volusia County has seen success with a similar effort at Tomoka State Park to divert oyster shells from the landfill, sending them back to become reefs again.

Email restoreourshores@brevardzoo.com to donate shells to the program.

Sign up to volunteer
People can volunteer for an oyster gardening opportunity thorough the Brevard Zoo's Restore Our Shores.

The zoo needs volunteers to bag oysters, prepare the oyster beds and anchor the bags to the estuary floor. Click here to find an upcoming oyster restoration volunteer opportunity.

Turn your river property into an oyster garden
If you live along the Indian River Lagoon, on a canal or lagoon bank, contact the zoo and volunteer your property to host a new reef.

Participants take a free class through Brevard Zoo and Restore Our Shores to learn how to maintain oysters from their docks during a two-hour workshop where all materials are provided.

Volunteers must agree to monitor the oysters and log their progress into a database.
Sign up for an upcoming course here.

For more information, contact Katey Leban at kleban@brevardzoo.org or at office: 321-254-9453 extension 376.

Adopt a mangrove

You don't have to live on the water, or even have a yard, to be a mangrove foster parent. Sign up for a mangrove gardening class with the zoo and raise a mangrove until it's ready to be turned back over to the zoo and planted along the lagoon shore. Don't have a green thumb? You can also volunteer to help plant the mature mangroves along the shoreline.

Click here to find a workshop.

More resources:

Here's how you can help improve the condition of Florida's waters

Visit restoreourshores.org to learn more about Indian River Lagoon restoration efforts.

The Florida Institute of Technology offers a free oyster restoration guide for people interested in restoring oyster reefs.