Scaling up investments in mangrove livelihoods for healthy people and the planet
As part of 2025’s ‘Harmony with nature and sustainable development’ theme for the International Day for Biodiversity, Alice Bian and Elizabeth Robinson discuss how financing the blue economy, specifically in relation to the protection and restoration of mangroves, a vital part of the Earth’s natural capital, could lead to broad health and livelihood benefits for all.
Nature-based solutions, specific actions or interventions that protect, sustainably manage, and restore natural ecosystems, are an emerging priority for achieving the transition to a resilient and prosperous net zero society. Climate change will drive more extremes of climate and weather for at least the next 25 years, even if global mitigation efforts hit net zero by 2050. Following the Glasgow Climate Pact, over 100 countries have integrated nature-based solutions (NbS) into their nationally determined contributions, which highlights the importance of addressing climate change mitigation and adaptation together.
Mangroves, coastal ecosystems composed of salt-tolerant shrubs and trees that are found particularly in sheltered upper intertidal areas of estuaries, can be considered the poster child of integrated approaches to realising climate mitigation, adaptation, resilience, livelihoods and biodiversity benefits for coastal and global communities.
The ocean is the planet’s greatest carbon sink, and mangroves contribute to sequestering blue carbon which is stored below ground at rates over four times higher than in other tropical and terrestrial forests. As a form of natural capital, mangroves provide ecosystem services in stabilising shorelines and reducing erosion, creating buffers for coastal defence that improve the resilience of local coastal communities against increasing impacts of climate change, such as storm surges, flooding and extreme heat. They are also vital for improving fishery breeding, spawning, and hatching grounds for offshore fisheries and increasing fish stocks, and therefore for income potential and food and nutritional security. Fisheries production is critical for over 3.3 billion people as an important source of protein, income and subsistence, particularly in lower-income countries. Mangroves also contribute to protecting and enhancing biodiversity, by providing critical habitats for, for example, Bengal tigers, proboscis monkeys, sloths and coral reefs. As such, mangroves have tremendous potential to contribute to accelerating the transition to a well-adapted, resilient net zero world.
Key drivers of mangrove loss include aquaculture and agriculture while challenges to conservation remain
Yet mangroves face multiple threats that affect population and ecosystem health. The global mangrove area decreased by over 20% between 1985 and 2020, from 17.41 million hectares to 13.66 million hectares, with associated carbon stocks declining by 16.5%, mainly due to land cover change. The Earth’s remaining mangrove carbon sinks provide approximately US$2.7 trillion in services every year, which amounts to US$194,000 per hectare annually. Between 2000 and 2020, the conversion of mangroves for aquaculture and agriculture, such as oil palm plantations and rice cultivation, accounted for 43.3% of global mangrove loss, while other drivers included natural retraction, exacerbated by the impacts of climate change, settlement for economic activities, and timber extraction.
Growing evidence suggests that cutting down mangroves is linked to increased health risks in coastal communities, including malaria, diarrhoea and other infectious diseases, which are more likely to spread when not protected by at least 500-metres of mangrove forest. The clearance of mangroves increases the risk of coastal flooding, which leads to stagnant water that can become a suitable breeding ground for mosquito-borne diseases such as malaria, and can increase the incidence of water-borne diseases, such as diarrhoea, negatively affecting public health. Mangrove loss is also threatening marine food security and nutrition through reduced availability of fish stocks, limiting the ability of small-scale fishers to access aquatic food for nutritional intake.
Undervaluation and under-regulation are critical root causes of mangrove loss, leading to underinvestment in their protection and restoration. There is a gap in knowledge and understanding of the local and global benefits of mangroves. The economic value of carbon sequestration and marine biodiversity protection is difficult to quantify, particularly due to the lack of data from lower-income countries. An improved understanding of the benefits of mangroves as perceived by local communities can provide additional robust evidence to justify the costs of mangrove restoration and protection, and to mobilise climate finance to increase the quality and quantity of mangrove cover.
Institutional and governance challenges are major inhibitors of effective mangrove conservation, and so need to be tackled in parallel. For example, there are some competing interests in achieving food security through efforts to promote sustainable aquaculture over mangrove restoration. In the absence of clear land tenure, inadequate enforcement of the legally mandated reversion of abandoned fishponds to regenerated mangrove forests remains a key socioeconomic challenge, exacerbating inequalities. Fragmented institutional efforts, aimed at strictly protecting 13.5% of the global mangrove distribution, primarily through marine protected areas, may undermine the potential for blue carbon and improved marine food security.
Mobilising blue carbon finance to improve mangrove livelihoods
Increasing community engagement and a better understanding of local community knowledge and priorities can ensure that local ecological knowledge contributes to broader efforts to improve understanding of the value of mangroves. For example, in the Philippines, fish catch for income and nutrition, flood protection, access to fuelwood, improved air quality, and carbon sequestration are the local benefits most highly ranked by indigenous peoples and communities.
Medicinal uses of mangrove plants, for example, from their leaves and barks, is an under-researched area and poorly documented in the scientific literature, yet there is likely a wealth of knowledge within communities living close to mangroves. Working more closely with local communities could be an emerging investment priority.
Strengthening the economic case for mangroves is a first step towards mobilising climate finance. A focus on improved economic valuation of the broad local health and livelihood co-benefits of sustainable mangrove management, particularly improved nutrition, can incentivise community participation as the guardian of natural resources. A better design of community-led payment for ecosystem services, such as mangrove blue carbon credits, can reward communities as a whole for not degrading and deforesting mangrove resources, while meeting increased investment needs to fund carbon offset projects that generate significant co-benefits to local communities, such as improved quality of life, health and employment.
Countries are increasingly looking for innovative blue finance mechanisms. Since the 2010s, debt-for-nature swaps have written off over US$6 billion from the face value of debt globally, particularly in the Caribbean region, with 60% of the reduced or restructured debt used to raise capital through blue bonds and blue loans for investments in marine protection. However, the actual amount of savings freed up for conservation projects amounted to just over US$100 million, primarily due to high transaction costs. The Seychelles issued the world’s first blue bond through a debt swap in 2018, yet since then there has been slow uptake, with only 26 blue bonds amounting to a cumulative value of US$5 billion, representing less than 0.5% of the sustainable bonds market. Many of the existing blue bonds lack clear impact metrics, with proceeds primarily focused on sustainable fisheries, rather than taking a holistic approach to the blue economy that can benefit local communities and small-scale fisheries.
Further research into the equitable design of blue bond frameworks, and a pipeline of income-generating livelihood projects, such as ecotourism and artisanal fishery value chains, have great potential to mobilise sustainable finance through capital markets for increasing marine protected areas that protect and restore mangroves.