About
Mangrove forests are unique ecosystems that thrive in the interface between land and sea. Specially adapted to living in salt and brackish water, mangrove trees are found along coasts and estuaries throughout 123 countries in the tropics and subtropics.
Although mangroves account for less than 1 per cent of the cover of global tropical forests, they provide critical ecosystem goods and services to the estimated 2.4 billion people living within 100km of the coast (UNEP, 2023). Mangroves provide protection against storms, erosion and flooding, sources of food and timber, improved water quality and carbon sequestration. Mangrove forests also provide natural habitat for over 1,533 different species, including nursery habitats for many commercially important fish, and are beneficial to the health of adjacent ecosystems such as coral reefs and seagrass meadows.
Ecological status and trends
Mangrove forests are threatened by many human pressures, including conversion to aquaculture and agriculture, coastal development, overharvesting, agricultural and industrial pollution, and climate change impacts. Based on global mangrove maps released by the Global Mangrove Watch, in 2020 there was an estimated 147,359 km2 of mangrove forest cover globally, 51 per cent of which occurred in the Asia-Pacific, with 29 per cent in the Americas and 20 per cent in Africa. Using 1996 as a baseline, this represents a net loss of 5,245 km2 (3.4 per cent) mangrove forest cover over the 24-year period. According to latest satellite imagery, the global loss of mangroves has stabilised, and gains have occurred in and around many of the world’s large rivers, estuaries and deltas (UNEP, 2023).
Beyond these figures, mangrove forests have been degraded, polluted and have lost biodiversity, impacts which cannot be seen by satellite imagery. Biodiversity in mangrove forests is increasingly at risk. 1,533 species are associated with mangroves in some way; 15 per cent of which are threatened with extinction. UNEP's report “Decades of Mangrove Forest Change: What does it mean for nature, people and the climate?” found that nearly 50 per cent of mangrove-associated mammals, 22 per cent of fishes, 16 per cent of plants, 13 per cent of amphibians and 8 per cent of bird and reptile species are threatened with extinction. Worryingly, for 44 per cent of the species, their extinction risk is increasing and of those already at risk, the situation is getting worse for 89 per cent.
Why Does it Matter?
Mangrove forests are disproportionately valuable to coastal peoples, despite their relatively small extent globally.
It has been estimated that mangrove-derived ecosystem services are worth US$33,000–57,000 per hectare per year, including from timber, fuelwood and construction materials, fisheries, medicinal compounds, water quality maintenance, coastal protection, ecotourism, nutrient cycling and provision of nursery habitats for commercially important species. Mangrove forests are also among the most carbon-rich ecosystems in the world and are important in mitigating climate change.
Loss and degradation of mangrove forests results in massive greenhouse gas emissions, and it has been estimated that emissions resulting from mangrove losses have resulted in economic damages of billions of US Dollars annually. Protecting and restoring mangrove forests is important as a climate mitigation and adaptation strategy, it supports the livelihoods of hundreds of millions of coastal peoples around the world and ensures the survival of thousands of species.
What We Do?
Mangrove forests and other blue ecosystems deliver effective nature-based solutions, and it is critical that we act now to protect, restore, and sustainably manage them so they can continue to deliver critical ecosystem services for nature, people and the planet.
UNEP is one of the world leaders in supporting climate change mitigation (e.g., blue carbon) and adaptation in the marine & coastal environment, through a wide range of partnerships with Governments, UN agencies, the Regional Seas Conventions and Action Plans, the Global Environment Facility, Civil Society and the Private Sector.
UNEP is delivering global leadership on mangrove ecosystems, promoting international cooperation and science-based and ecosystem-based management approaches, supporting regional and global assessments, developing best practice manuals, and working with partners to implement conservation and restoration projects on the ground. UNEP is committed to supporting the achievement of the Global Biodiversity Framework targets and advocates for the effective restoration of 30 per cent of degraded marine and coastal ecosystems and the protection and better management of at least 30 per cent of the ocean.
Mangrove protection and restoration is central to the UN Decade on Ecosystem Restoration (2021-2030) which seeks to galvanize efforts to restore degraded and destroyed ecosystems to enhance food security, clean our air, secure freshwater supplies, address the climate crisis and protect habitats that support life on Earth. The UN Decade of Ocean Science for Sustainable Development (2021-2030) also highlights mangroves as an ecosystem to inspire advances in science and technology to improve ocean health.
Facts
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1,533 species are associated with mangroves in some way; 15 per cent of which are threatened with extinction.
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Nearly 50 per cent of mangrove-associated mammals, 22 per cent of fishes, 16 per cent of plants, 13 per cent of amphibians and 8 per cent of bird and reptile species are threatened with extinction. Worryingly, for 44 per cent of the species, their extinction risk is increasing and of those already at risk, the situation is getting worse for 89 per cent.
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Mangroves are a significant global carbon store and sink, with the largest average carbon stocks per unit area of any terrestrial or marine ecosystem. The global average carbon stock of mangroves is around 1,000 tonnes of carbon per hectare, including soil carbon.
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Between 1996-2020 mangrove forest loss released the equivalent of approximately 4 times the global CO2 emissions of fossil fuel burning and the manufacture of cement in 2018.
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Emissions resulting from mangrove losses make up nearly one fifth of global emissions from deforestation, resulting in economic damages of US$6–42 billion annually.
UNEP reports
https://www.unep.org/resources/report/importance-mangroves-people-call-action-0
https://www.unep.org/resources/report/guidelines-mangrove-restoration-western-indian-ocean-region
“Related to” Topics (Climate Action, Pollution Action, etc.,)
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Nature action
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Climate action
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Freshwater
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Food systems
