Mangroves are species of plants and shrubs that live on the land or shallow water or both – being flooded by seawater for part of each day. They have adapted to their salty environment by being able to turn salt water into fresh water and pushing out the salt through the pores in their leaves. They are typically found along inland waterways and sheltered coasts.
Around St. Maarten, four species of mangroves can be found:
Red Mangrove (Rhizophora mangle), which typically grows along the water’s edge, is found at Mullet Pond, Simpson Bay Lagoon and some areas around Fresh Pond. It has tangled, reddish roots called ‘prop roots’ that are usually exposed at low tide but covered at high tide. Its leaves are large and egg-shaped, dark green on the top and light green on the bottom. The fruit it produces looks like a pencil.
Black Mangrove (Avicennia germinans) grows in muddy or sandy soils further inland than the Red Mangrove. Its wood is dark brown to nearly black, and its leaves are narrow and egg-shaped with pointy ends. It has many finger-like projections, called pneumatophores, which protrude from the soil around the trunk. These help bring extra oxygen to the tree.
White Mangrove (Laguncularia racemosa) grows on land farther upland than the Red Mangrove and Black Mangrove. Its thick leaves are light yellow green and have two distinguishing glands at the base of the leaf blade where the stem starts. The fruit it produces is small, dry, leathery and ribbed like a prune.
Buttonwood (Conocarpus erectus) grows high on land away from the reach of the tide. Its greenish flowers have a button-like appearance and grow in branched clusters, forming cone-like fruit. The leaves are long and pointed and have two salt-excreting glands located at the base.
Mangroves are one of the most valuable natural resources on the planet. They support extensive coastal food webs, provide shoreline stability and protect coastlines from erosion by storm waves. They also help keep the water clean; their roots filter and prevent the sediment from reaching and smothering coral reefs. Though mangrove ecosystems provide a unique and valuable range of resources and services, huge areas of mangrove continue to be lost to agriculture and urbanization. It is estimated that about 60% of the total mangrove areas in the world have disappeared. The healthy areas of mangrove forest that remain on St. Maarten are therefore significant worldwide and must be urgently protected from further damage.
Mangrove wetlands provide a vital habitat for many animal species, from fish to conch to birds. Marine invertebrates found in St. Maarten’s mangroves include the endangered Queen Conch (Strombus gigas), Upside Down Jellyfish (Cassiopeia frondosa), Sea Cucumber (Holothuria mexicana) and Sea Urchins (Tripneustes venricosus, Lytechinus variegates, Meoma ventricosa). Fish species include wrasses, parrotfish, silversides, herrings and anchovies. One key function of mangroves is their role as a nursery for reef fish, including Schoolmasters (Lutjanus apodus), Gray Snapper (Lutjanus griseus), Great Barracuda (Sphyraena barracuda) and the Foureye Butterfly (Chaetodon capistratus).
Mangrove areas provide a perfect habitat for roosting, nesting and migrating wetland birds. Several species of birds breed in and around the mangroves of St. Maarten, including the American Coot (Felucia Americana), Moorhen (Gallinula chloropus), Yellow-crowned Night Heron (Nyctanassa violacea), Green Heron (Butorides striatus), Black-winged Stilt (Himantopus himantopus), American Oystercatcher (Haematopus palliates) and several plovers.
Of the 19 mangrove ponds on St. Maarten, only four remain today: Red Pond, Fresh Pond, Little Bay Pond and Mullet Pond. Development pressures and pollution threaten these remaining mangroves areas. The start of the construction of the Simpson Bay Lagoon Causeway in 2012 has meant the clearing of much of the lagoon’s mangrove forest. To compensate for this loss, the St. Maarten Nature Foundation has replanted thousands of juvenile mangroves in the lagoon as well as at other locations on St. Maarten.