Seagrasses are an integral component of our aquatic ecosystems and are indicators of the health of the surrounding area. Not only are seagrasses a source of food for wildlife, they serve as habitat and carbon storage; therefore, they are vital to our ecosystem. Between 2011 and 2021, approximately 75% of the Indian River Lagoon’s seagrasses were lost, and natural recovery is estimated to take a minimum of 12 to 17 years. (Morris, Jan. 2022).
Seagrasses are and have been subjected to major stressors such as reduced light, salinity extremes, and excessive nutrients, which play a critical role in their ability to thrive and survive. A major contributor to seagrass death has been brown tide (Aureoumbra lagunensis) blooms that repeatedly shaded out the seagrass. Excessive nutrients cause algal blooms, such as brown tides, which reduce light penetration needed for seagrass photosynthesis.
Under contract to the Brevard County Natural Resources Management Department, CSA Ocean Sciences Inc. is working with EAI to create a geospatial seagrass site selection decision tree that will include recommendations for seagrass planting site selection, restoration designs, monitoring protocols, and reporting. Suggested project design and monitoring plans are being developed to fill critical knowledge gaps prior to large scale restoration action.
In creating this tool, CSA and Brevard County are utilizing existing data to create risk classifications for potential seagrass planting areas. Each class will have suggested manipulators to explore factors limiting seagrass colonization, persistence, and percent cover within that risk class to optimize future planting efforts. This approach will allow practitioners to focus questions and guide methods based on the empirical results of planting success.
More Project Examples
In addition to its work with Brevard County, EAI has been involved in several submerged aquatic vegetation projects that include freshwater and estuarine environments on Florida’s east and west coasts. In 2018, EAI performed an assessment for impacts to seagrasses in Stump Pass, Charlotte County, Florida. EAI’s restoration plan was developed in conjunction with multiple regulatory agencies seeking remediation of the impacts to seagrasses. In August and September 2019, a Time Zero monitoring event was performed at the impact and restoration sites. EAI will conduct subsequent monitoring annually at the end of each growing season when seagrasses are most abundant. Annual monitoring is required for at least five years and shall continue until success criteria are met for two consecutive years without maintenance to ensure that the seagrass mitigation site is sustainable.
Submerged aquatic vegetation plays an integral role in healthy freshwater ecosystems. Together with Martin County and Sea & Shoreline, LLC, EAI has performed eel grass planting within stormwater treatment areas for the uptake of excess nutrients. Most recently, this team has worked to plant eel grass in Martin County’s Salerno Creek stormwater treatment area. This project comes after a 2020 project in the Coral Garden stormwater treatment area. EAI has conducted monitoring of the eel grass planted in both locations and has also monitored water quality to document the positive effects of these eel grass plantings.
EAI is pleased to be part of the effort to restore seagrasses, which falls in line with our company’s mission to plan for a better future by working with government and industry to preserve the good nature of our communities. Visit ecological-associates.com for more information.
Mature turtlegrass (Thalassia testudinum) and manatateegrass (Syringodium filiforme) bed on the Gulf side of the Florida Keys.
MORRIS, L.J., Hall J, Jacoby C, Chamberlain R, Hanisak M, Miller J, Virnstein R. 2022. Frontiers | Seagrass in a Changing Estuary, the Indian River Lagoon, Florida, United States | Marine Science (frontiersin.org)
 The referenced articles’ data ends in 2019. After confirming with Brevard County, the updated percentage of lost seagrass through 2021 is included.