Seed-Based Seagrass Restoration

Traditional seagrass restoration methods typically involve removing sediment and seagrass plugs from an established healthy seagrass bed and planting them in another area. However, collecting these plugs can potentially be harmful to the donor beds. To eliminate this risk, researchers at FWC are developing new restoration methods using “seed-based” restoration. This entails collecting turtle grass (Thalassia testudinum) seedlings and growing them in an aquaculture nursery for future restoration site plantings.

Turtle grass is a dominant species of seagrass in Florida and provides many ecosystem services such as food, nursery habitat and sediment stabilization Turtle grass can reproduce both sexually and asexually. Sexual reproduction produces fruits containing seedlings that are released into the water column from July through August. Some of these pea-like seedlings will settle on the seafloor and become new seagrass plants, while others will get washed ashore. FWC scientists are collecting the shore-cast seedlings for restoration research and growing them to sufficient size before outplanting them into Tampa Bay.

Three images showing a woman kneeling in shallow water sifting through seagrass, five seagrass seedlings showing different stages of growth, and multiple black containers filled with sand and early seagrass growth.

Since 2022, FWC has been successfully collecting and growing turtle grass seedlings in a greenhouse. The goal is to create a model that can easily be replicated and adopted by other agencies and organizations for future seagrass restoration efforts. Some of the variables being studied to create the ideal planting unit (PU) are sediment type, planting densities and genetic variation among seedlings collected across the state.

Three images showing a diver holding a small seagrass plant and using a shovel to dig a hole in the sand, a diver underwater looking at a small bunch of seagrass, and a seahorse attached to a blade of seagrass.

To date, there have been approximately 2,000 nursery-grown turtle grass plants outplanted to a restoration site in Tampa Bay. These seedlings are monitored monthly and have already become a valuable habitat to local fauna. This pilot study will inform future restoration efforts about how to utilize shore-cast seedlings.

If you have any questions about our seedling- based restoration projects, please email SeagrassRestoration@MyFWC.com.

Replenishing Seagrass from Seedlings

For decades, FWRI scientists have carefully monitored seagrass health throughout Florida, witnessing both alarming die-offs and encouraging signs of recovery.