From Ancient Shell Mounds to Modern Reefs: Restoring Oysters in Brevard County

The story of oysters in the Indian River Lagoon is one of abundance, decline, and hope for renewal.

Excavated shell midden in Florida showing layers of oyster and clam shells left behind by early Indigenous communities. — Shell midden partly excavated near Ponce de Leon inlet in Volusia County, 1920-12. Shell middens are evidence that oysters were once abundant in the Indian River Lagoon. Many were dug up to use as roadbed along I-95. *State Archives of Florida*

‍1. A Rich History of Oysters in the Indian River Lagoon

Thousands of years ago, long before the shoreline was dotted with docks and seawalls, the Ais people lived along the lagoon’s edge. They harvested oysters and clams for food and tools, leaving behind towering shell mounds called middens.

One of the largest, the Pentoaya Midden, covered 1.8 hectares (4.5 acres) near where the Eau Gallie River meets the Indian River Lagoon in present-day Melbourne. Layers of oyster and clam shells mixed with pottery, bones, and other artifacts tell of a place rich in life and activity. Spanish maps from the 1600s show Ais villages in this very spot, evidence of a community sustained by the lagoon’s bounty.

Aerial map from 1943 of the Eau Gallie River and Indian River Lagoon area, marking the historic Pentoaya midden site and shoreline changes. — *Aerial photograph from 1943 showing the location of the potential Pentoaya site in Brevard County, where shell and other fragments have been found.* *Brevard County Historical Commission, The Indian River Journal, Volume VII, Number 1*

2. The Decline of Oyster Habitat

Over time, the landscape changed. Research in Mosquito Lagoon, north of Brevard, shows oyster habitat declined by about 24% between 1943 and 2009.

The causes were many: seawalls and riprap now line roughly 64% of Brevard’s shoreline, removing natural spaces where oysters could grow. Fertilizer, septic systems, and stormwater runoff carry nutrients that feed algae blooms, reducing oxygen and smothering reefs. Freshwater from canals alters salinity levels, disrupting reproduction cycles.

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Early 1900s postcard view of the Eau Gallie River meeting the Indian River Lagoon, showing undeveloped shoreline and a small passenger boat. — *View Looking Eastward to Indian River at Mouth of Eau Gallie River, 1906 Postcard.* *Brevard County Historical Commission, The Indian River Journal, Volume VII, Number 1*

3. Why Oysters Matter

Oysters are more than food—they’re architects of the lagoon’s ecosystem. A single oyster can filter up to 30 gallons of water daily, reefs shelter fish and crabs, and their structures help protect shorelines from erosion.

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Illustration showing oyster reef benefits: oysters filter water, reefs shelter fish and crabs, and oyster structures protect shorelines from erosion.

4. Restoring What Was Lost

Today, the story is shifting toward recovery. In Brevard County, restoration efforts unite science, volunteers, and community support:

The Save Our Indian River Lagoon Program (SOIRL) is investing in oyster restoration because oysters are natural water filters and habitat builders. Oyster bars provide shelter for more than 300 species of fish, crabs, and other wildlife. Working with partners like Brevard Zoo’s Restore Our Shores and the University of Central Florida, SOIRL helps build and monitor reefs using recycled shell and innovative designs. The program’s plan includes 28 oyster restoration projects, strategically placed along both natural and hardened shorelines to reestablish oysters where they once thrived. Guided by an adaptive strategy, SOIRL tracks growth and habitat benefits to refine approaches over time. To date, more than 80,000 square feet of oyster habitat have been restored across Brevard County. As these reefs expand, they filter more water, support more marine life, and act as natural breakwaters—laying the foundation for a healthier lagoon ecosystem that benefits both people and wildlife (Brevard County SOIRL Project Plan).

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See how Cocoa Beach is using oyster prisms, gabions, and other innovations at McNabb Park to help create habitat and filter water for a healthier Indian River Lagoon. YouTube

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City-Level Examples – Local shoreline projects demonstrate results on the ground. In Cocoa Beach, the McNabb Park living shoreline incorporates oysters and mangroves and is estimated to remove 96 lbs of nitrogen and 32 lbs of phosphorus every year (City of Cocoa Beach). Watch a video about McNabb Oyster restoration here: YouTube
Indian River Lagoon National Estuary Program (IRL NEP) supports regional projects, including a 2007 partnership with The Nature Conservancy, UCF, and Canaveral National Seashore to restore reefs in Mosquito Lagoon.

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Volunteers at Brevard Zoo’s oyster shell recycling site preparing shell-filled gabion cages for Restore Our Shores reef restoration projects. — *Learn how Restore Our Shores continues to refine oyster gardening, adapting strategies to strengthen reef restoration and boost project success.* *YouTube*

But it’s not just science—it’s community. At the heart of restoration efforts is Restore Our Shores (ROS), the Brevard Zoo’s conservation program. For nearly a decade, ROS has connected everyday people to the lagoon’s resurgence.

Oyster Gardeners: Local lagoon-side residents grow young oysters off their docks, nurturing them for six to nine months. These “spat” eventually move to reef sites during a special “Homecoming,” where restoration communities come alive. This program has already produced over 500,000 oyster juveniles, illuminating the best spots for new reef planting.
Building with Purpose: Volunteers help assemble gabion reefs—metal cages filled with recycled shell—and newer “corrals,” shell-enclosed structures that mimic reef conditions. In one corral trial near Melbourne Beach, volunteers helped cultivate 40,000 oysters, and the reefs became homes for more than 20 species.
Digging Deeper: With support from Restore America’s Estuaries, ROS is studying oyster reproductive health and larval settlement across Brevard County. Volunteers help sample oysters and track water quality. Earlier this year, ROS constructed half an acre of oyster habitat and is monitoring it under SOIRL’s five-year plan.
Ways to Pitch In: Whether you live on the lagoon or not, there are meaningful ways to join in. Volunteer roles include oyster gardening, reef building, shell preparation, mangrove planting, and more. The 2025–2026 oyster gardening season is now open for sign-up, and ROS also hosts supply preparation meetups for oyster habitat materials.

5. How You Can Help Write the Next Chapter

The story of oysters in Brevard County isn’t finished. You can help shape its future:

Avoid using fertilizer from June 1–Sept 30; if you can't eliminate use year-round, make sure to choose zero-phosphorus, 50% slow-release nitrogen formulas the rest of the year.
Keep yard waste out of streets and drains.
Pick up pet waste to prevent bacteria and algae-feeding pollution from entering waterways.
Reduce runoff with rain barrels, rain gardens, or permeable pavers.

Volunteers wade into the Indian River Lagoon placing oyster restoration materials, with cages of recycled oyster shells stacked on shore.

The lagoon’s past reminds us of its resilience—and with community action, we are turning the tide. Join Lagoon Loyal to find more lagoon-friendly tips, tricks, and ways to get involved. Together, we can help oysters once again thrive in the waters of our Indian River Lagoon.

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