Life among the mangroves

Straddling the land and the sea with a tangle of arching roots, mangrove trees guard coastlines all over the world. Mangroves recycle pollutants, maintain water quality, and provide habitat and a secure source of food for wildlife and people. They also play a vital role in climate health. The trees can store carbon for hundreds—sometimes even thousands—of years, making mangrove forests among the most carbon-rich habitats on Earth. Mangrove forests cover roughly between 33 million and 49 million acres of the globe and are one of the most complex and productive ecosystems on the planet.

Among the tangled root systems, reaching branches, and fluttering leaves of mangrove forests, you can find a colorful variety of wildlife who call these trees home. Their leaves are the basis of an incredibly productive food web, beginning with providing nutrients for algae and invertebrates, which in turn feeds many other organisms. The reach of the benefits that mangroves provide goes much beyond forest boundaries. The role of mangroves in ecosystem function serves to protect wildlife from all around the world.

Proboscis monkey

Easily recognized by its bulbous and elongated nose, the endangered proboscis monkey is found in the mangrove swamps of Borneo and Indonesia. Protected by the thick tree canopy from predators like the estuarine crocodile and clouded leopard, these monkeys elect to rest and sleep among the trees. It is typical for proboscis monkeys to feed on the mangroves. They have an appetite for young leaves or shoots, flowers, and young fruits found in the trees. In fact, proboscis monkeys have special bacteria in their stomachs that help to digest mangrove leaves, enabling the digestion of cellulose, a fiber found in plants, and ridding the leaves of any potential toxins. Unfortunately, mangrove deforestation threatens the monkey’s habitat, food source, and, subsequently, population numbers.

Mangrove tree crab

Mangrove tree crabs live along the Atlantic Coast, from Florida to the southern coast of Brazil. These small crustaceans rely on mangroves for both habitat and food. During high tide, you can find the crabs scurrying up mangrove tree branches as they seek refuge from the impending waters. As the tide recedes, the crabs prefer to shuffle along the base of the mangrove swamps, scavenging in tree roots for food, including parts of the trees themselves. Red mangrove leaves make up an estimated 84% of an adult mangrove tree crab’s diet. These crabs serve as a link between the primary production of mangroves and the detrital, or decomposer-based, food web. This contributes to the overall ecosystem health of the mangrove forests in which they reside.

Dugong

Swimming in the seas that reach East Africa’s mangrove swamps can be found the dugong, a vulnerable marine mammal that is often mistaken for its cousin, the manatee, due to its gray appearance and oblong body. The relationship among mangroves, dugongs, and the seagrasses they feed on supports the survival of all three. Mangroves serve as buffers to storm surges for coastal communities, and this power is amplified with the assistance of seagrasses. Seagrasses stabilize sediment to reduce the impact of the sea’s current and surges to protect mangrove trees. In return, mangroves filter out this sediment and excess nutrients that would otherwise damage the seagrasses, enhancing the productivity and resilience of seagrasses for dugongs to feed on. Dugongs are considered an indicator species for their habitat, meaning that when dugongs are sighted in our seas, healthy seagrasses can be found beneath the water’s surface.

Mangrove finch

The rarest bird in the Galápagos, the mangrove finch, can only be found fluttering among the branches of the mangrove forests on the western islands of the Galápagos. These iconic Darwin finches are small, typically only about 14 centimeters long, boasting olive-toned brown plumage and delicate beaks. Mangrove finches use these beaks to carefully lift mangrove tree bark and rummage through fallen piles of leaves to search for insects. They rely on mangrove forests to sustain their eating habits. With only around 100 individuals remaining, this species is in critical danger of extinction. In fact, mangrove finches are one of the most range-restricted birds in the world. Previously claiming habitat on two Galapagos Islands, Fernandina and Isabela, the mangrove finch can now only be found on the northwest coast of Isabela. The pristine mangrove forests of Isabela are necessary for the highly specific habitat requirements of the mangrove finch, making this specific patch of mangrove forest vital to the survival of this critically endangered species.

Key deer

The Florida Keys are known for their idyllic beaches, and this strip of islands also features more than 1,800 miles of coastline dotted with mangroves. Here, one can find the key deer, an endangered deer species of only about 700 to 800 individuals left. Threatened by habitat loss due to rapid development, automobile collisions, disease, and the alteration of its habitat by a changing climate, key deer seek refuge in the mangrove forests of the Florida Keys. Faced with a depleting population and shrinking habitat area, mangrove conservation is a hot topic in the state as key deer populations shrink along with their habitat. Much like many other species whose habitat lies among the mangroves, conservation of mangroves and of key deer are ultimately intertwined.

Continental tiger

Some Continental tigers prowl amid the entangled tree roots of mangrove forests. They rely on the foliage to stay hidden and stalk their prey. One of the most unique habitats for these iconic big cats is the Sundarbans mangrove forest, shared by India and Bangladesh. This UNESCO Heritage Site is the only forest where tigers live along a marine coast. The Sundarbans not only protect the tigers who live inside them but the communities outside. These magnificent trees protected coastal communities in Bangladesh and India from storm surges. Tigers are predators by nature and lie at the top of the food chain in the wild. Because of this, they play a profound role in ecosystem function overall, including that of the Sundarbans mangroves. Maintaining tigers thus means maintaining tiger habitats, which has great implications for the protection of humans and other wildlife in the area.

With projects in the Sundarbans, Pakistan, Coastal East Africa, Mexico, Madagascar, Colombia, and Belize, WWF works with partners around the globe to promote the conservation of mangroves. WWF and partners, including many fisheries and coastal communities, aim to promote the restoration of mangrove forests while helping to improve sustainable fishing practices.

The positive impact of preserving the health and integrity of mangrove forests around the world goes beyond protecting the many great services they provide. Protecting mangroves also means protecting wildlife and humans.