Mangroves are among the most misunderstood ecosystems. The coastal forests are sometimes perceived as “dirty” or “dead areas”, wasted land that could be cleared in favour of sandy beaches or other developments.
These myths about mangroves could not be farther from the truth. They are the only trees that thrive in salty waters and improve water quality by filtering out nutrients and sediments.
They are also teeming with life: more than 1,500 plant and animal species depend on mangroves. This includes fish and birds who use the shallow waters beneath mangrove trees as nurseries. Research now indicates that mangroves are also critical for larger mammals, such as monkeys, sloths, tigers, hyenas and African wild dogs.
But mangroves are threatened. Worldwide, a fifth of them have already disappeared. In some places around the world, such as the Irrawaddy Delta, over 80 per cent of mangrove forest has been lost since the 1970s! The main driver of mangrove loss is coastal development, when mangrove forests are cleared to make way for buildings and fish or shrimp farms.
The plight of these vital ecosystems will be in the spotlight on 26 July, World Mangrove Day. Below are five key benefits of mangrove ecosystems paired with winning entries from the Mangrove Photography Awards, an annual competition partnering with the United Nations Decade on Ecosystem Restoration and the UN Decade of Ocean Science.
1. Mangroves are climate heroes
To keep climate change at bay, the world urgently needs to reduce emissions and remove carbon from the atmosphere. Mangroves are critical in this second task. They extract up to five times more carbon than forests on land, incorporating it in their leaves, branches, roots and the sediments beneath them – therefore building ground level and keeping pace with sea level rise. The salty and oxygen-poor conditions beneath mangrove forests mean that decomposition of organic material happens very slowly. In the right environmental conditions, mangroves can store the carbon they took from the atmosphere for decades, centuries, or even millennia.
2. Mangroves protect against extreme weather and disasters
Not only do mangroves help prevent the progression of climate change, they also play an important role in limiting its impact.
As global temperatures rise, extreme weather events like storms and flood surges are becoming more likely. The trunks of mangroves absorb the impact of waves, making them excellent defenses against such hazards. Restoring and protecting mangroves is therefore a vital contribution to increasing the resilience of coastal communities and national economies. In eastern Ghana, the UN Ocean Decade-endorsed MANCOGA project aims to develop a robust and participatory Nature-based Solution that uses mangroves to address coastal flooding, erosion, pollution and biodiversity loss to strengthen community resilience. Along with other measures, investments in mangroves are expected to generate benefits around four times greater than the costs.
Mangroves have also been found to be an effective defense against tsunamis, reducing wave heights between 5 and 35 per cent.
3. Mangroves are a haven for threatened animals
Of the over 1,500 species that depend on mangroves for their survival, 15 per cent are threatened with extinction. This number is increasing when looking at mammals: Nearly half of mammals living or feeding in mangrove forests could go extinct in coming years, with trends worsening for most of them.
In the Sundarbans mangrove forest, the decline of Hental palm (Phoenix paludosa) – the most preferred habitat for tigers, as the thickness of the trees helps them camouflage themselves – has led to increasing incidences of tiger-straying in the area.
Protecting and restoring mangrove forests thus means bringing back critical habitat for vulnerable animal species like tigers and jaguars. The good news is that restoration works! Initiatives in Indonesia and the United Arab Emirates have been recognized as UN World Restoration Flagships for bringing back nature in coastal ecosystems.
4. Mangroves boost food security
As biodiversity havens, mangroves boost a huge variety of plants and animals, many of them important for food production. They act as nurseries for young fish and home to honey bees.
For 1.5 billion people, fish is the most critical source of protein and in low-income food-deficit countries, nearly 20% of the average animal protein intake comes from fish. The disappearance of mangroves would have dramatic consequences for fisheries in developing countries.
Conversely, restoring mangroves could add 60 trillion young, edible and commercially valuable fish and invertebrates to coastal waters every year.
5. Mangroves can bounce back naturally
Bringing lost ecosystems back to life is a daunting task. When communities along the coast of Java, Indonesia, started replanting mangroves to conquer rising sea levels, the results were sobering: only 15-20 per cent of planted saplings survived. The rest was simply washed away with the tides.
With the help of researchers and partners – such as Wetlands International – the villagers tried out a new solution: trapping the mud with seawalls made of natural materials, giving young mangroves space to recover naturally. The results were astounding. Mangrove survival rates shot up from 20 to over 70 per cent. The Building with Nature Initiative has since been recognized as UN World Restoration Flagship for its success.
Natural regeneration is now recognized and tried out in other parts of the world, together with other restoration approaches suited to local conditions. Understanding and addressing the drivers of mangrove loss is the first step towards ecosystem restoration.
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The UN Decade on Ecosystem Restoration 2021–2030:
The UN Decade on Ecosystem Restoration 2021–2030, led by the United Nations Environment Programme, the Food and Agriculture Organization of the United Nations and partners covers terrestrial as well as coastal and marine ecosystems. A global call to action, it will draw together political support, scientific research and financial muscle to massively scale up restoration. Learn more here.
The UN Decade of Ocean Science 2021-2030:
The UN Decade of Ocean Science for Sustainable Development (2021-2030), led by UNESCO’s Intergovernmental Oceanographic Commission, aims to support efforts to reverse the cycle of decline in ocean health and gather ocean stakeholders worldwide behind a common framework that will ensure ocean science can fully support countries in creating improved conditions for sustainable development of the ocean. Learn more here.
The Mangrove Photography Awards:
Mangrove Action Project is running its ninth annual Mangrove Photography Awards. The competition invites photographers of all levels around the world to contribute their images to celebrate the beauty and diversity of mangrove forests and inspire action to conserve them. Today, less than half the world’s original mangrove forests remain, and it has never been more important to promote the conservation of these fragile ecosystems through inspiring photography. These powerful images are a compelling reminder of the vital role mangroves play and inspire us to protect them for future generations. In celebration of World Mangrove Day, discover stunning mangrove images from across the globe. Learn more here.
