A look at the current state of mangrove forests worldwide, how we got here, and plans for the future of these delicate yet critical ecosystems.
By Ellen Rubin
Edited by Nina Purton
Despite their important role in environmental maintenance, the economy of local communities, and specific natural ecosystems, mangroves have been neglected, exploited, or destroyed over time.
Luckily, Mangroves can become productive in a relatively short amount of time once restoration work has begun. Restoring coastal habitat increases wildlife populations by 61%, and diversity becomes 35% greater than in unrestored areas.
Several national and international organizations are taking steps to protect and restore their natural mangrove heritage. Let’s explore the current state of mangrove ecosystems across the globe.
World Distribution of Mangrove Forests
Africa – 21%
North & Central America – 15%
Australia & Islands of Oceania – 12%
South America – 11%
Distribution of Mangrove Species – Source: Research Gate
In 2020, mangroves covered an estimated 137,760 square kilometers or 53,190 square miles, distributed among 118 territories and countries, although almost 75% are found in just 15 countries. The Global Mangrove Watch puts mangrove size at 147,250 square kilometers.
The state of mangrove forests is in flux and, unfortunately, decreasing. Since 1996, approximately 3.5% of the forests have been completely lost. This rate of decrease has stabilized, resulting in some gains around the world’s large rivers, estuaries, and deltas according to a 2023 survey by the United Nations Environment Programme (UNEP). What is not clear in satellite imagery behind this data is forest quality. Population and biodiversity continue to decrease, as evidenced by the number of species that remain or become endangered.
In the past 50 years – especially prior to 2000 – development and pollution contributed to a 35% reduction in mangrove acreage. Between 1996 and 2020 it declined by about 3.4% — 40% of which was due to coastal development.
As people have become more sustainably conscious, deforestation has slowed. Research hast found that 1-2% of our mangrove forests are disappearing every year. While 50% of the world’s mangrove forests remained intact at the end of the 20th century, half of these were in poor condition.
The American Museum of Natural History said mangroves are “among the most threatened habitats in the world.” Meanwhile, the IUCN Red List of Mangrove Ecosystems calculates that one out of every five mangroves ecosystems are considered endangered, threatened, or vulnerable.
State of Mangroves Forests
With growing awareness of the importance of mangrove forests, efforts have been made to maintain what is left, and even restore the parts that have been neglected or destroyed. The amount of protected forest has increased by 17% since 2012, and 42% of the world’s mangroves are now protected.
Asia tends to lose mangrove forests at nearly double the average global annual loss. This happens across a cohort of countries including Indonesia, Malaysia, Papua New Guinea, Solomon Islands, Brunei, East Timor, Singapore, and the Philippines.
Below is the state of some protected, and unprotected forests.
The Bay of Bengal
The Bay of Bengal is host to the largest mangrove forest at 3,900 square miles.
The Sundarbans forest covers 1 million hectares (2.47 million acres) in India and Bangladesh and is famous for its biodiversity. It is the home of 270 species of birds, 35 reptiles, and 42 mammals including the endangered Bengal tiger and Indian python. In addition to being crucial to endangered species, the forest also acts as a protective barrier to millions of people from cyclone flooding.
A large portion of habitat has been lost to intensive agriculture with only a few enclaves of forest remaining. That said, from 2001 to 2012 there was almost no tree cover lost.
UNESCO has protected this area as a World Heritage Site. Even so, the Sundarban was still designated as endangered in the IUCN Red List of Ecosystems in 2020 because of diminishing mangrove and fish species.
Myanmar
Mangroves in Myanmar suffer a rate of loss three to five times higher than the global average. This is especially troubling because this region is also one of the world’s greatest biodiversity hotspots and has enormous potential as a carbon sink.
Indonesia
Indonesia is comprised of 17,000 islands and is home to one-fifth of the world’s mangroves.
Indonesia’s mangroves have been almost halved half in the last three decades. In 1982 there were 4.2 million hectares, but only 2 million remained in 2000. Indonesia’s minister of fisheries and marine affairs, Fadel Muhammad, says that of what remains, “70% are in critical and seriously damaged condition.”
The eastern coast of Kalimantan has left wide areas vulnerable to deforestation to make way for palm oil development or shrimp farms. They currently have very minimal conservation efforts and from 2001 and 2012 lost between 9,000-25,000 hectares (22,000-62,000 acres) of forest each year.
Other Mangrove ecosystems across the globe
Australia is home to the third largest area of mangroves spans about 20% of the coast. This represents 6.4% of the world’s total mangrove coverage.
Mangrove losses in Thailand and Mexico to make room for temporary shrimp pens are also significant. Not only is the loss of territory impactful, but the biowaste generated after the pens are removed renders the water too toxic for most forms of life. Therefore, without significant remediation, mangroves can’t be regrown in the near future.
Mangrove protection and restoration
Many countries and organizations have recognized the importance of mangroves by enacting regulatory protections and restoration projects. There are currently 685 protected areas, divided among 73 countries and territories worldwide containing mangroves. Australia has 180, Indonesia 64, and Brazil 63.
Restoring mangroves could add up to 60 trillion young, edible, and commercially valuable fish and invertebrates to coastal waters yearly. Mangrove ecosystems also help mitigate increasingly violent weather events, increase biodiversity, provide habitat for endangered species, and economically support nearby communities.
Protection methods
With protection and time, mangroves can bounce back naturally; although usually, these areas need some constructive help getting started. There are several different methods used to help foster new growth.
One of the fastest and most economical ways to distribute seed pods is by using drones. With the help of these, organizations can accomplish what would take people weeks of planting in just a few days — at a fraction of the cost.
The Building with Nature Initiative/Wetlands International program has experimented with semi-permeable seawalls that trap mud and sediment, protecting newly planted trees in their infancy. The system increases the success rate of new trees from 20% to over 70% and it’s now being used in other parts of the world.
Another restoration option is to plant new trees along with small pieces of iron in pierced bags that contain nitrogen and phosphorous fertilizer. In a mission to replace 70% of mangrove loss, 700,000 trees have been planted in Indonesia using this method.
Credit: FroyR – Own work
Source
Nations Conserving Mangroves
There are several noteworthy restoration projects across the globe. These include:
- Indonesia and the United Arab Emirates have been recognized as UN World Restoration Flagships for bringing back diversity in coastal ecosystems.
- In Africa, Tanzania created an environmental management plan for mangroves beginning in 1990, nicknamed “mama mikoko“ (“mama mangroves“ in Swahili).
- Regulations across Belize have successfully slowed down the loss of mangrove forests – only 2% was lost over the last 30-year period. The loss near coastal settlements was higher but averaged only 0.07% per year between 1980 and 2010. Protected forests and ecosystems have contributed US$174-294 million per year to their national economy.
- In Thailand and Madagascar, restoring black mangroves has increased honey production so communities have a source of disposable income. This is the same ecosystem that accommodates endemic silkworms for another source of income.
- Northern Ecuador has done a great deal of conservation work, especially along the estuaries in the Esmeraldas region.
- Java in Indonesia has experimented with building brushwood barriers along the coastline to create the stable base sediment needed for floating mangrove seeds to root and regrow. As trees take root, the barrier can be moved further out.
- In Florida, the Nature Conservancy supports the Blowing Rocks Preserve from the Panhandle to the Keys to restore red mangroves along the shoreline.
- The Manzanar Mangrove Initiative in Arkiko, Eritrea is working to establish new mangrove plantations on coastal mudflats using nutrients in the water flow from inland areas.
- In Eastern Ghana, the MANCOGA projectuses mangroves to reduce coastal hazards such as flooding, erosion, and pollution. They are also increasing the economic and physical resilience of communities.
Global Organizations Working on Restoring Habitat
Many NGO organizations have involved themselves in helping to restore forests and work with local communities to provide the resources necessary.
AXA’s Community Forestry
This participatory approach advocated by the research fund for development AXA involves both communities and smallholders in governing and managing the forest resources to achieve long-term sustainability.
UNEP
The UNEP works with governments, other UN agencies, civic societies, and the private sector to help restore forests.
They are committed to supporting the achievement of the Kunming-Montreal Global Biodiversity Framework targets, which include the effective restoration of 30% of the degraded marine and coastal ecosystems, and the protection and better management of at least 30% of the ocean.
The United Nations Educational, Scientific and Cultural Organization (UNESCO) has designated the 26th of July as the “International Day for the Conservation of the Mangrove Ecosystem. This is part of an effort to raise awareness of the importance of mangroves as a ‘unique, special and vulnerable ecosystem’ and to promote their sustainable management, conservation and use,” according to UN News.
World for Wildlife FUND (WWF)
The international non-governmental organization’s subsidiary the Global Mangrove Alliance is a leader in mangrove tracking, restoration, and stabilization.
With the mission to “Halt Loss. Restore Half. Double Protection,” they’re also determined to increase habitat by 20% by 2030.
The alliance is a collaborative network of almost 70 NGOs, research groups, and philanthropic organizations committed to increasing the range of mangrove habitats and protecting existing forests through global policy change and scientific advancement. Their website has an interactive map of their worldwide initiatives, a complete list of members, and a comprehensive report on the state of mangroves.
The WWF, supported by the Bezos Earth Fund has also implemented the “Mangroves for Communities and Climate” program which has 5-year grants aimed at protecting, restoring, and strengthening the management of 2.47 million acres of mangroves in 20 countries including Mexico, Madagascar, Fiji, and Columbia. These grants address climate change by helping sequester 2 billion tons of carbon and will protect 300,000 people living near these coastal forests.
Ramsar Convention
The Ramsar Convention is an international treaty that strives to guarantee the protection of national marine protected areas.
To become a signatory, a country must designate at least one site and guarantee its protection. To date, the 110 signatories have pledged to protect 850 sites, covering 53 million hectares which contain ⅓ of the existing mangrove forests.
Global Mangrove Watch
The online platform Global Mangrove Watch provides current and interactive maps of mangrove habitats and loss, species placement, or monitoring mangrove areas. Global Mangrove Watch is a great source for organizations, leaders, and nature enthusiasts.
Reflections for the near future
Appointed the Decade of Ecosystem Restoration and Ocean Science for Sustainable Development (UN), the time frame between 2021-2030 is set with a series of milestones that promise to protect mangroves and other natural ecosystems. Alongside this, the UN also support the annual Mangrove Photography Awards, encouraging awareness through visual expressions.
Included in the many goals for the Decade are efforts to:
- restore degraded and destroyed ecosystems which will enhance food security
- clean the air
- secure freshwater supplies
- address the climate crisis
- protect the habitats that support life on Earth
If you want more information on mangroves, the United Nations Food and Agriculture Organization and the Global Mangrove Alliance offer reports on the current state, threats, and mapping of worldwide mangroves.