In 1938, the state of Florida built a bridged road out to Marco Island, near Naples. Inadvertently, the bridge cut off the natural flow of seawater and killed over 250 acres of vital mangrove forest habitat. Today, 75 years later, efforts are being made to repair the damage. And the project just got some unexpected help from a Chinese billionaire.
The Daily Bucket is a regular series from the Backyard Science group. Here we talk about Mother Nature in all her glory, especially the parts that live nearby. So let us know (as close as you are comfortable) where you are and what's going on around you. What's the weather like? Seen any interesting plants, bugs or critters? Are there birds at your feeders? Deer, foxes or peahens in your yard? Seen any cool rocks or geological features? Post your observations and notes here. And photos. We like lots of photos. :)
Collier County is one of the largest counties in Florida. It is also one of the most sparsely populated; the only large city is Naples. In the southern part of the county, a couple hours (EDIT: about 20 miles) south of Naples near the Everglades, is Marco Island, one of the barrier islands that ring the coastline. Few people lived on Marco until 1927, when a spur from the Atlantic Coast Railroad was extended to the island. In 1937, it was decided to connect Marco Island to US Route 41, the main automobile highway that ran down the west coast of Florida. State Road 92, now known as San Marco Road, was built over a causeway bridge that crossed the intercoastal waterway to the barrier island. The project was finished in 1938. The island soon became a haven for high-end seaside houses.
But unknown to the builders, the road and the residential construction were causing an ecological catastrophe. Marco Island was covered by an extensive area of mangrove trees, which were critical to the environmental health of the island. Not only did the tangled prop roots provide shelter for the eggs and young of many fish and invertebrates, but the trees protected the shoreline against storm erosion by holding the sandy soil in place, as well as creating new land area by trapping and holding sediment.
In 1938, there was no such thing as an "environmental impact study" for construction projects, and the road builders and contractor companies had not considered their effect on the mangroves. The causeway built for SR92 had a drainage culvert installed to allow coastal water to pass through the bridge, but it was not large enough, and restricted the water flow. As more houses were built over the years, the construction waste and the runoff sediments from the lawns filled in the natural channels that connected the mangrove patches to the sea. As a result, an area of mangrove forest covering some 250 acres became slowly isolated: sea water could no longer flow in, and rainwater could not flow out. The mangroves became stressed as the salinity in the diluted water fell to levels they could not tolerate. The final blow came in 1992 when Hurricane Andrew dumped huge amounts of rain on the area, which ran into the mangrove swamps and could not flow out. The standing water drowned the trees, killed off the oxygen-loving bacteria in the sandy soil, and eliminated all the fish and invertebrates that had depended on the mangroves. By 1995, the entire area was a wasteland of dead mangrove stumps jutting out of the smelly anoxic mud and stagnant water.
A couple years later, professional ecologist Robin Lewis happened to be vacationing in the Naples area when he saw the devastated mangrove tracts and thought he might be able to help. Lewis's 501(c)3 nonprofit foundation, Coastal Resources Group Inc., had already carried out a number of mangrove-restoration projects in Florida. By 2000, Lewis and CRG were partnering with the Conservancy of Southwest Florida to carry out a scientific study of the problem. The solution, they decided, was a fairly simple one: by clearing out all of the former channels and adding a better water-flow system through the bridge, the natural flow of seawater in and out of the inlet would be restored, the stagnant freshwater would be carried away, and the mangrove swamps could be restored to health. In most projects of this type, thousands of mangrove seedlings are hand-planted to help restore the forests--an expensive and labor-intensive process. But Lewis proposed a new idea that he called "Ecological Mangrove Restoration": instead of hand-planting new mangroves, effort would be focused on restoring a suitable habitat and then allowing Mother Nature to restore the mangroves naturally as the propagules found and colonized the new area. Lewis's plan would take place in three steps: Phase 1A would restore the natural water flow to a small test area to prove the concept. Phase 1B would then clear the natural channels and restore sea flow to the rest of the 250-acre area. Finally, Phase 2 would install a series of 48-inch culverts through the SR92 bridge to restore natural water flow from one side to the other.
By now, the US Fish and Wildlife Service and the Rookery Bay National Estuarine Research Reserve had also become interested in the project. After several years of work to obtain the necessary permits, the USFWS provided a grant of $75,000 (and local citizens raised a total of $15,000) to carry out the Phase 1A work in February 2012. A narrow channel was dug and the water began to flow to a 4-acre test area. The effect was dramatic: mangrove seedlings began to appear, and the stagnant waterlogged soil began to clear. Biologists monitored the area by marking and measuring every new mangrove sapling. By December 2012 hatchling fish, crabs, and marine snails began to arrive. The once-dead mudflat now was showing new signs of recovery. The area is still being monitored and studied by the Rookery Bay Reserve and by the US Geological Survey.
Convinced that their plan would work, the team now hoped to carry out their next steps--restoring the water flow to the remaining areas and modifying the bridge--and obtained all the necessary permits. But here they ran into trouble: the total cost would be somewhere around $2 million. NOAA pledged a grant of $450,000, but only if the local groups could raise $150,000 in matching funds. The team also tried to get funding from the state of Florida, using money that had come from British Petroleum in compensation for the Gulf of Mexico oil spill. But as of the end of 2015 the project was nowhere close to being funded.
Then a miracle occurred. Out of the blue, in January 2016 a proposal arrived from Wenliang Wang, owner of the Rilin Industrial Group in China. Wang, with an estimated net worth of over $1 billion, had an interest in global environmental issues. He had already donated millions of dollars to wetlands restoration projects in China and reforestation efforts in Brazil, and when he heard about the mangrove project in Florida, he decided to offer his help. Wang has pledged up to $5 million towards the Marco Island project and similar mangrove restoration efforts.
Since the project already has all its permits and is "shovel-ready", work is expected to begin early this year.
And now it’s your turn: what’s up in your neck of the mangroves? :)