Record Mangrove Restoration—One Year Later

Florida’s largest mangrove restoration project - located on east San Marco Road on Marco Island - is now one year into its recovery, and a Time Zero Plus Twelve Months Monitoring Report is showing signs of recovery in the huge mangrove die-off area, according to aquatic habitat conservation and restoration specialist Jamie Wolanin.

"This February marked the one-year anniversary of the completion of the Fruit Farm Creek Mangrove Restoration Project,” said Wolanin, "which is the largest of its kind in Florida. We are already seeing signs of success in the form of mangrove growth and tidal water exchange and expect the habitat to continue to improve and support a wide variety of wildlife in the coming years.”

One of the key objectives of the restoration project involves restoring tidal flow to the 209-acre area. Four five-foot diameter culverts were installed under San Marco Road, replacing a single culvert that had been choked off by vegetation over the decades it had been in place. Wolanin is happy with the current flow.

"The water level loggers in the project site were only intended to capture data one time after construction completed,” Wolanin said, "but we did get good results. As of the Time Zero Monitoring Report from May 2023, two of the three loggers are showing water levels that routinely drop below ground level and rise again with the tides. This indicates that there is a strong connection to tidal influence in these areas. It is great that we have seen evidence of the restoration area’s reconnection to the rest of the system so soon after construction was completed.”

Part of the objective of the project is to see mangrove growth within five years. Wolanin said Rookery Bay biologists, tasked with monitoring the die-off area, are already seeing progress, although they haven’t seen much new mangrove growth yet.

"Monitoring data indicates that canopy cover and the diameter of the live mangrove trees in our plots have both increased in the year since construction was completed,” she said, "but we aren’t seeing many saplings yet. It is important to note that our reference sites adjacent to the project area are still recovering from damage sustained during Hurricane Ian in 2022, so the whole system is expected to continue to improve over time.”

The game plan is for mangrove propagules to plant themselves as they are brought into the die-off area with incoming tides. While the results have been meager so far, Wolanin is not overly concerned.

"Of the eight plots established in the restoration area for vegetative monitoring, we have only found saplings in two of them so far,” Wolanin said. “This is as expected based on the condition of the site at the time of restoration. We should see more propagules establishing throughout the affected marsh in the future."    

Wolanin feels confident that the die-off area will show the expected signs of recovery by 2028.

"Based on current recovery data,” she said, "we expect the site to be in great condition and a valuable habitat for many species of wildlife by five years post-construction.”

One of the objectives of the restoration is for tides within the die-off area to look just like the tides outside of the area. However, one area of the project is not emptying as expected.

"The tides inside a majority of the project area do resemble those outside of the project area,” she said. "The water level logger in the easternmost area of the project is showing us that some standing water remains even at low tide. We believe this is due to the low land surface elevation in this area. We would like to see this water drain just as well as the rest of the project has.”

Part of the criteria for success involves the path the tide takes as it flows in and out.

"Tidal flows are following dredged channels and flooding the affected marsh according to our modeled flow ways effectively,” Wolanin said. “There is a section of the marsh where minor channel establishment would help tidal flushing.”

That can be accomplished with adaptive management, which is part of the original plan.

"To establish better tidal connections in the eastern section of the restoration area,” Wolanin said, “FWC (Florida Fish and Wildlife Conservation Commission) and partners have discussed the possibility of digging a few small channels. This would create a path for the water to follow in and out of the system and be very minimally invasive to the recovering mangrove forest. It is a priority of FWC’s Aquatic Habitat Conservation and Restoration Section to see the goals of the Fruit Farm Creek Project through to completion.”

For the most part, Wolanin likes the data she's receiving from Rookery Bay’s monitoring program. 

"Monitoring is going well,” Wolanin said. "We have collected data on water level, number of mangroves and their life stages, canopy cover, and animals using the habitat at multiple plots in the project area. The Time Zero Plus Twelve Months Monitoring Report was put together with data collected in February 2024 and is expected to be completed later this month. The project will continue to be monitored periodically for a total of five years post-construction."

Wolanin has been a biologist for FWC’s Aquatic Habitat Conservation and Restoration Section, working to restore freshwater, marine, and estuarine habitats in southwest Florida for a little over a year. She has a Bachelor of Science in Biology from Grand Valley State University and a Master of Science in Marine Biology from Northeastern University.