Mangroves certainly don’t get the interest and protection they deserve. That's why we've created this officially endorsed Ocean Decade Toolkit providing key facts, imagery and other tools needed to help create awareness and inspire action.

Mangroves are the world's most important trees

Mangroves provide an essential nursery for three-quarters of tropical fish.

Mangroves = Fish

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Intertwined mangrove roots offer protection from predators as well as small food sources for young aquatic creatures. Many mangrove-dwelling fish species are essential to commercial fisheries. It has been estimated that 30% of the fish caught in Southeast Asia are supported in some way by mangrove forests. 

There are also a few that are listed on the IUCN Red List of Threatened Species, such as the near-threatened rainbow parrotfish and critically endangered goliath grouper. 

In addition to acting as a nursery habitat for juvenile fish, mangroves also act as a habitat for stationary filter-feeders like sponges, anemones and oysters that cling to the hard surface of mangrove prop roots.

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Mangroves are excellent at reducing carbon in the atmosphere — some are up to 10 times better than forests on land.

Mangroves = Climate Action

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Like all trees, mangroves are carbon-absorbing machines. As they grow, mangroves pull carbon dioxide out of the atmosphere and use it to build their roots, branches and leaves. Then, when leaves and branches break off or when a tree dies altogether, the absorbed carbon stays within the tree, sinking to the seafloor and eventually being buried under sediment. This is why the carbon they absorb is called “blue carbon."

Mangroves’ ability to store blue carbon makes them especially valuable for fighting climate change — even more so than terrestrial forests. In fact, pound for pound, blue carbon ecosystems can sequester 10 times more carbon than boreal, temperate or tropical forests on land. Although mangroves account for less than 2% of marine environments, they carry out 10 to 15% of global carbon burial.

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Coral reefs need the fish that grow up in mangroves. Mangroves also provide a safe habitat for corals, protecting them from storms and heat waves due to climate change.

Mangroves = Coral Reefs

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Along with many reef fish spending the first years of their lives enjoying the protection of mangrove forest roots, coral reefs themselves (and nearby seagrass beds) benefit from being situated near these coastal forests. 

Mangroves help corals and seagrasses in a number of ways. First, they reduce the ocean’s acidity, which helps keep corals strong. Additionally, they filter the runoff water that flows to seagrass beds and reefs, which shields these habitats from algal blooms and generally improves water quality. 

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Mangroves help animals such as the endangered Bengal tiger survive.

Mangroves = Survival

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It isn’t just the endangered fish species that benefit from mangrove forests. Over 30 plants and animals ranging from “Vulnerable” and “Critically Endangered” on the IUCN Red List of Threatened Species have been associated with mangrove habitats, whether for finding prey or protection. These range from aquatic hawksbill turtles and dugongs to terrestrial Bengal tigers, Sambar deer and king cobras.

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There are numerous stories of mangroves being the difference between life and death for people living in coastal communities.

Mangroves = Protection

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Mangroves can significantly reduce the impact of strong surges that are responsible for flooding during large storms. Studies have found that mangrove forests can cut storm-related deaths by two-thirds and the overall force of a tsunami by 90%. Because of how they’re positioned on the shoreline, mangroves also protect communities from coastal erosion. 

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Mangroves have been valued at over $3.3 million per square kilometer per year to the economies of developing countries with mangroves.

Mangroves = Wealth

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Between the benefits of mangroves as coastal protection, carbon storage, biodiversity protection and a food and livelihood source, these coastal forests have an estimated worth of about $33,000 to $57,000 per hectare per year, which translates to $3.3 to $5.7 million per square kilometer. Many communities and governments, especially those of developing nations, benefit greatly from the value of their mangroves.

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Mangroves are amazing at repopulating. Their seeds can float across the ocean. With a little help, mangroves can bounce back surprisingly quickly.

Mangroves = Mangroves

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Mangrove seeds, also called propagules, start to grow while still attached to the parent tree. After the propagules drop off the tree, they’re swept away by ocean currents, floating until they become waterlogged, sink to the seafloor and take root.

White mangroves can float up to about 24 days, but red mangrove propagules can float and grow for up to a year before taking root — enough time to cross the entire ocean. This allows them to settle in areas where they don’t have already established mangrove colonies to compete with.

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Download and use free photos and video from our Ocean Image Bank

The 7 main reasons why mangroves are so important……

Clear-cutting of mangroves for urban, industrial and tourism development has made a major impact on ecosystem size. These forests are often destroyed to make new beaches, give houses an “ocean view” and build waterfront businesses for tourism and entertainment. 

Along with the development comes further disturbances like light and noise pollution, harmful fumes, and often damaging practices like anchoring on reefs, feeding wildlife and collecting plants and shells as souvenirs. These can significantly damage any remaining mangroves in the area.

We’ve chopped down mangroves to build houses and businesses.

While mangroves are some of the greatest fighters of climate change, they’re also being destroyed by climate-related threats like underwater heat waves and sea level rise.

In 2016, marine heat waves that caused catastrophic coral bleaching also caused the worst mangrove mass die-off ever recorded. As ocean temperatures continue to rise, it’s becoming increasingly likely that marine heat waves will happen more frequently and continue to put these ecosystems in jeopardy.

Another effect of climate change that’s threatening mangroves is sea level rise. Projections show mangroves will only be able to tolerate sea level rise for the next 35 to 50 years. After this point (and even before then in some areas), the trees will no longer be able to cope with the influx of saltwater and surging tides.

We’ve killed mangroves through heat waves and sea level rise due to climate change.

Believe it or not, the single biggest threat to mangroves is the commercial farming of an animal that’s naturally found in these forests: shrimp. The shrimp aquaculture industry has rapidly expanded in recent decades, and to keep up with the demand for these shellfish, hundreds of thousands of acres of mangrove forests have been cleared to make shrimp farms.

The waste from the shrimp farms causes toxic levels of pollution, which means farms need to be regularly moved to new locations and the mangrove forests struggle to grow back.   

We’ve chopped down mangroves to farm cheap shrimp.

In many developing coastal communities, chopping down mangrove trees for charcoal and timber has become a common way to make a living. The wood from mangrove trees makes an excellent building material, and it can also be made into high-quality charcoal for cooking.

The downside to this is that many of the communities that have turned to mangrove charcoal and timber production have done so because fisheries are on a steep decline. As workers chop down more mangrove trees, they are clearing valuable habitat that could be key to fish populations bouncing back.

We’ve chopped down mangroves for timber and charcoal for cooking.

Clearing forests for land isn’t the only way farming is destructive to mangroves. The fertilizers, pesticides and other chemicals that are used on farms inland eventually make their way into the ocean through runoff water. This polluted runoff can poison mangroves as they try to filter the seawater that surrounds them. 

We’ve killed mangroves through pollution.

Who’s doing good and what good are they doing?

What have we gone and done to mangroves?

The Global Mangrove Alliance is all about streamlining conservation efforts by connecting scientists, governments, local communities, funders and other groups across the world. It has run more than 270 projects in over 50 countries that are centered on mangrove restoration, research, policy, climate, livelihoods and more. One of its biggest initiatives is the launch of Global Mangrove Watch, a web-based monitoring system that offers real-time data about changes to mangroves around the world. The platform can be accessed by anyone and is especially useful for researchers, governing bodies and other groups that are looking to make data-driven decisions about mangrove conservation.

Conservation groups such as those in the Global Mangrove Alliance have helped slow the rate of mangrove
loss in recent years.

While repopulating mangrove forests seems like an easy conservation win, it can be quite difficult to do correctly. In fact, between 1984 and 1992, over $35 million was spent replanting 3 million mangrove seeds, and by 1996, less than 20% had survived. 

One of the reasons mangroves are so hard to replant is that when the trees are destroyed, the sediment and soil they thrive in erodes. This makes it difficult to plant mangroves in the same spot down the line. 

Thankfully, after years of study, individuals and conservation groups have developed techniques to successfully replant mangrove forests. These include replicating the hydrology of natural mangrove habitats and planting multiple species to create a more biodiverse wetland. Using specialized methods, millions of mangroves have been replanted worldwide by groups including the International Society for Mangrove Ecosystems.

Supporting certain mangrove projects is now an established way to buy carbon credits.

Conservation groups and governments have replanted millions of mangroves (although getting it right is still a huge challenge).

Mangroves are excellent at spreading their seeds, also called propagules, naturally. This can help them repopulate forests on their own, but organic repopulation can be more effective when the plants get a little help from us humans. 

Mangrove Action Project is one organization that uses the Community-Based Ecological Mangrove Restoration (CBEMR) technique to help regrow mangrove forests. CBEMR involves local stakeholders and urges for action not only to facilitate natural regeneration but also to reduce any stressors leading to mangrove decline. Mangrove Action Project has proven this method can result in healthy repopulated forests. 

Conservation organisations such as the Mangrove Action Project have helped mangroves naturally repopulate large areas of forest.

Ocean water isn’t even the saltiest habitat mangroves can live in — they can tolerate water up to two times the salinity of the sea.

So, how do they tolerate these extreme conditions? Depending on the species, mangrove trees can either store and excrete the salt from their leaves or block it from entering their roots altogether. Mangroves are so good at filtering ocean water, in fact, that you could actually drink fresh water from their branches.

Mangroves are the only trees that tolerate salt water.

Scientists have identified 54 true mangrove species and an additional 30 or so species that are often grouped in with mangroves because they have some similar traits and live in the same habitats. However, these mangrove-associated species don’t have all of the unique adaptations of true mangrove trees.

There are over 50 species of mangroves.

Mangroves vary widely in height based on where they’re located. For example, trees in Florida grow an average of 6 to 15 meters, depending on the species. In Gabon, Africa, however, they have been found growing up to 60 meters. Gabon’s Pongara National Park is home to some of the tallest mangroves in the world.

Some mangroves grow up to 60 meters tall.

You don’t need to know much more about mangroves…

…but we think you might like to.

Restoring the Natural Mangrove Forest | Mangrove Action Project

Measuring Mangroves: Explorers in the Field | National Geographic

Mangroves: How They Help the Ocean | The Economist

Carbon Credits for Kenyan Mangroves | UN Environment Programme

Why Mangroves Matter | Conservation International

The Mangrove Ecosystem | National Geographic

Mangroves: Goods and Ecosystem Services | Mangrove Action Project

Coastal Blue Carbon | The Nature Conservancy

The Importance of Mangroves to People: A Call to Action | UN Environment Programme

International Society of Mangrove Ecosystems

Dr. Alfredo Quarto | Mangrove Action Project

Dr. Octavio Aburto | National Geographic Explorer, Scripps Institution of Oceanography

Dr. James Kairo | Kenya Marine and Fisheries Research Institute

Professor Boone Kauffman | Oregon State University

Professor Catherine Lovelock | University of Queensland

Imagery provided by Ocean Image Bank photographers: Alex Mustard, Ariph Rasheed, Fabrice Dudenhofer, Hannes Klostermann, Lorenzo Mittiga, Matt Curnock, Santanu Majumdar, Soham Bhattacharyya, Srikanth Mannepuri, Toby Matthews.

A toolkit to help raise awareness of mangroves — the world’s most important trees. Use it to help inspire mangrove protection and restoration.