Mangroves are vital ecosystems for our planet – uncover exactly where they are most threatened in the world, and why
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Mangroves are tropical trees or shrubs that grow in coastal saline water where other species cannot survive. They are largely found in tropical and subtropical regions near the equator and are home to a variety of animal and plant species.
These ecosystems bring many benefits to our planet, but climate change is threatening their ability to survive with scientists believing that half of all mangroves are at risk of collapse by 2050.
Why are mangrove forests important?
One of the biggest benefits of mangroves ability to protect communities lining the coastlines, preventing erosion and limiting the effects of storms and flooding. It is estimated that they protect 15.4 million people and USD 65 billion worth of property per year from coastal disasters. The forests also act as natural water filters, reducing pollutants and contaminants and improving water quality.
For animals, mangrove forests are equally important as they provide a safe space for many marine animals to breed and raise their young. Many mammals, birds and reptiles also inhabit these forests, depending on the plant life for nutrients.
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Mangrove forests, like many plant ecosystems, are also capable of sequestering huge volumes of carbon. It is thought that mangroves could store up to three to five times as much carbon as a tropical rainforest, making their disappearance even more concerning for our planet.
Sea-level rise is the biggest threat affecting mangrove ecosystems. Under a business-as-usual scenario, around 25 per cent of the global mangrove area is predicted to be submerged in the next 50 years. Without any additional conservation efforts, by 2050, about 7,067 sq km of mangroves will be lost and 23,672 sq km will be submerged. The ecosystems are also threatened by deforestation, land use changes and construction of sea defences.
So where are the five biggest mangrove areas at risk? Below we reveal them in reverse order according to their classification, using data from the IUCN’s Red List of ecosystems.
5. The Tropical Northwestern Atlantic – Vulnerable
The Tropical Northwestern Atlantic mangroves span regions including the Greater Antilles, the Gulf of Mexico, and the Caribbean, covering 17,408 sq km and representing 11.8 per cent of global mangroves. Mangrove forests in this region face threats such as deforestation, urbanisation, and sea-level rise, which could submerge more than 75 per cent of them by 2060 under severe scenarios.
Anthropogenic impacts on the ecosystem vary between countries, but overall, the ecosystems are highly vulnerable to changes.
The Everglades National Park in Florida is home to the largest mangrove forest in the US. Mangroves can be found along the coast of Florida, as far north as Cedar Key on the Gulf Coast and Ponce de Leon Inlet on the Atlantic coast. Because of the threats to mangrove forests in recent decades, the park is now legally protected at state and federal levels with legislation to regulate the trimming and removal of the plants and shrubs.
NASA satellite imagery of the National Park has shown that these conservation efforts have slowed the decline rate in the past two decades.
4. The Eastern Coral Triangle – Endangered
The mangroves of the Eastern Coral Triangle are vital ecosystems covering areas in the Bismarck Sea, Solomon Archipelago, Solomon Sea, and Southeast Papua New Guinea. These areas host 46 different mangrove species and 242 animal species, some of which are endangered.
Mangrove forests in the Eastern Coral Triangle face threats, including illegal logging, sea-level rise, and land use conversion. Their extent has decreased by 15 per cent since 1970, and under high sea-level rise scenarios, 61.5 per cent may be submerged by 2060. Currently, they are classified as endangered.
The Coral Triangle is a known biodiversity hotspot, also home to 76 per cent of all known coral species on the planet. The risks of sea level rise, pollution and overfishing to mangroves and coral reefs in the region have prompted six governments around the Coral Triangle to partner up with the aims of conserving the ecosystems through marine protection areas and more sustainable fishing practices.
Their efforts also aim to support the livelihoods of 120 million people reliant on these resources.
3. The South China Sea – Endangered
The South China Sea mangroves include intertidal forests and shrublands across regions like the Gulf of Tonkin and South China Sea oceanic islands, covering Vietnam’s coast, southern China, Taiwan, and Hainan Island. Their total area in 2020 was 543 sq. km, contributing 0.4 per cent of global mangrove resources, though their distribution is patchy in the region due to factors like steep coastlines and exposure to open seas.
Overharvesting of wood and aquatic products, alongside pollution from industrial activity, is threatening mangrove forests and the development of coastal infrastructure and land reclamation.
These processes have led to widespread degradation of the ecosystems and continuation of the current trend could see a further 15 per cent decrease in mangrove coverage by 2070.
2. The Red Sea and Gulf of Aden – Endangered
The mangroves of the Red Sea and the Gulf of Aden occur in small patches along the coastlines of several countries in the region, including Djibouti, Egypt, Eritrea, Saudi Arabia, Sudan, Yemen, and Northern Somalia. They are found in a harsh, arid environment and are made up of two key species: Avicennia marina and Rhizophora mucronata.
These ecosystems face significant pressures from coastal development, pollution, and rising sea levels. Uncontrolled camel grazing, oil spills, habitat destruction and irresponsible tourism have been further major threats. Under extreme sea-level rise scenarios, up to 67.1 per cent of these mangroves could be submerged by 2060.
Conservation efforts in recent years have aimed at reducing habitat loss, including initiatives to protect mangrove areas through stricter management policies and restoration projects. In the next decade, conservation efforts will include expanding protected areas, such as marine reserves and nature parks, continuing mangrove restoration and rehabilitation efforts, and promoting public awareness and community involvement in conservation initiatives.
1. South India, Sri Lanka and the Maldives – Critically Endangered
The mangroves of South India, Sri Lanka, and the Maldives are critically endangered and account for 249.2 sq. km, or 0.2 per cent of global mangroves. These areas face numerous threats, including reduced freshwater flow, land conversion for aquafarming and tourism, and climate impacts such as sea-level rise and storm surges.
If current trends continue, a 49-58 per cent loss is projected over the next 50 years, with up to 82.7 per cent submerged by 2060 under high sea-level rise scenarios.
Interestingly, the ecosystems in the nearby Bay of Bengal region shared by India and Bangladesh and those in the west shared by India and Pakistan are in the least concerned category.
In southern India, particularly in Tamil Nadu, local fishermen are participating in sustainable mangrove restoration efforts to protect the coastlines. They use biodegradable baskets made from palmyra leaves to grow mangrove seedlings, which are a more environmentally friendly alternative to plastic bags. This method supports the seedlings’ growth and prevents damage to their root systems.
Additionally, the use of palmyra leaves provides an income source for locals involved in weaving the baskets, making the restoration project a win-win for both the environment and people.
