Mangroves are tropical to subtropical intertidal forest ecosystems, subject to saltwater tidal immersion. While they can adapt to brackish conditions, and can be found in bays that serve as freshwater watersheds, they are not solely components of freshwater ecosystems. They are often found at the mouths of streams and rivers. Mangroves are “landbuilder communities,” they extend shorelines via systems of prop roots, trunks, pneumatophores, and saplings that trap and stabilize erosional terrestrial sediments. It has been reported that in some fringing mangrove systems, prop roots can result in anywhere from 25 to 200 meters of coastal accretion a year. In areas with high turbidity, fringe mangroves may act to slow sediment runoff and filter suspended solids. The accumulation of sediments furthers the process of deposition and shoreline extension, and elevates the land surface. Peats may also develop in low-energy environments. Because of their high organic content and calm waters, mangrove forests serve as nurseries for many species of both invertebrates and reef and marine fishes. They also provide subsistence for many species of crustaceans, wading birds, and small mammals. Mangrove forests are, therefore, extremely productive ecosystems with very high biodiversity.
Coral Reefs and Submarine Canyons
Salt River Bay is protected from the sea by a barrier reef, composed primarily of finger corals and elkhorn corals; however, much of this reef is dead and overgrown with encrusting corals, sponges and algae. The offshore environment is dominated by a submarine canyon, composed of a shallow pavement shelf (30 to 50 feet; 9 to 15 m) that gradually drops into a deep forereef, ranging in depth from 50 to70 feet (15 to 21 m). The canyon then plummets to a depth of over 12,000 feet (roughly 3,650 m). The shelf consists of scattered elkhorn, brain, fire, boulder, and staghorn corals, while the walls are dominated by lettuce leaf corals (Agaricia spp.), sponges, and other soft corals; the canyon floor consists of seagrasses and seaweed beds.
Last updated: April 27, 2018