Mangrove swamps are found along the coasts in tropical and subtropical locations. They can live in salty water – so are halophytic. Because mangroves often line estuaries, where freshwater rivers flow into the ocean, the water is often brackish – a mix of fresh and salt water. As the water rises and falls every day with the changing tides, the saltiness (salinity) also changes. Because of this, mangroves have to be adapted to the changing salinity. Their leaves have specially adapted glands that secrete the salt they take in, plus a waxy covering (cuticle) that keeps their own water from being lost. This allows them to live in a salty environment without drying out.
Mangroves have a lot of biological diversity with a rich assortment of wildlife in their ecosystem. Because they have thick vegetation, they provide cover for many species of birds, including snowy egrets, white ibis, brown pelicans, frigate birds, and cormorants. Sea turtles, manatees, lizards. monkeys and even alligators are found in the mangroves. Their large, arching roots house smaller animals like crabs, snails, barnacles, oysters, mussels, anemones, and sponges. They are rich in organic matter (dropped leaves, buds, seeds, bark, etc.) which provides food. They act as a nursery habitat for many species of larval shrimps and crabs. Many species of fish also feed there. The bacteria in mangroves are very important, acting as decomposers and breaking down organic matter making it is available to the food web.
Mangrove are threatened by habitat destruction as they were once cleared for beach front development. Their loss in some coastal areas is marked by increased erosion, animal species loss, and increased storm damage. It is now illegal in Florida to cut down a mangrove tree.
Research and discuss why protecting mangroves is important to coastal integrity.
