Based on recently completed survey work the Mangrove Reforestation Initiative of the area surrounding the Simpson Bay Causeway has resulted in approximately 700 square meters of valuable Mangrove Habitat supporting a number of bird and wetland species. The Nature Foundation initially planted more than 500 square meters of mangroves after the construction of the Causeway and one year after the completion of the project did numerous follow-up surveys in order to determine the success of the project.
In the initial stage of the project juvenile mangroves were removed and were replanted at various locations around the island. Follow-up stages included reforestation techniques, monitoring, replanting initiatives and ecosystem management of the area. Based on all of these initiatives a total of 7850 new mangroves covering an area of 600 square meters was recorded during follow-up monitoring on the 13th of January 2014 and an additional 100 square meters during monitoring recorded late in February 2015. The survey also established numerous wetland bird species and seagrasses during the monitoring. There was also a reduction of the algae bloom which affected the area during the summer of 2014. This is considered a successful reforestation project and one of the most successful mangrove reforestation initiatives on St. Maarten to date and has started to provide mangrove seedlings for other areas surrounding the Simpson Bay Lagoon. The area has also become one of the most ecologically significant mangrove habitat in the south-eastern section of the Simpson Bay Lagoon.
Mangrove forests are under severe pressure and disappearing at an alarming rate and it is estimated that about 60% of the total mangrove areas have disappeared. All four species of mangroves were recorded at the Causeway namely Rhizophora mangle (Red mangrove), Avicennia germinans (Black mangrove), Laguncularia racemosa (White Mangrove) and Conocarpus erectus (Buttonwood).
Invertebrates were also recorded including Queen Conch (Strombus gigas), Cushion Stars (Oreaster reticulata), Sea Cucumber (Holothuria mexicana), and the Upside Down Jellyfish (Cassiopeia frondosa).
Mangroves also act as a filter for water being washed off the land by preventing harmful sediments from smothering the coral reefs, including those of the Man of War Shoal Marine Protected Area. By establishing themselves successfully, the mangrove trees have the potential to become a thriving habitat for many other plants and animals as well as an important nursery for many species of fish. Fish using the mangroves as a nursery include Schoolmasters (Lutjanus apodus), Gray Snapper (Lutjanus griseus), Great Barracuda (Sphyraena barracuda) and the Foureye butterfly (Chaetodon capistratus).