The State of the World's Mangroves

This 2024 edition of The State of the World’s Mangroves.

Mangroves are critical ecosystems, bridging land, freshwater and sea. They host tremendous diversity and protect and provide for countless coastal communities around the world. This 2024 edition of The State of the World’s Mangroves highlights the tremendous advances that have been made on multiple fronts to safeguard these ecosystems. It showcases progress in: science and understanding; collaboration and information sharing; practical management interventions; and the many policy, legal and financial tools that will help to secure a better future for these ecosystems.

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ENGLISH EXECUTIVE SUMMARY

MANGROVE SPOTLIGHT

FRENCH

SPANISH

WHY MANGROVES?

Mangroves are ecosystems of hope, bridging land, freshwater and sea. The 15 million hectares of mangroves across the globe host tremendous diversity, protection qualities and provide for countless coastal communities. Mangroves are not only places of great beauty, they are also among the world’s most productive ecosystems. They are fish factories, carbon stores and seawalls.

21B

Tons of CO2 stored

15M

People protected

600B

Shrimp and fish produced

341+

Threatened marine species

WATCH & LEARN

RISK & OPPORTUNITY

50% of mangroves are at risk of collapse by 2050. While rates of mangrove loss have decreased, our knowledge of their value and importance has increased. Today, over 42% of remaining mangroves are formally protected for conservation purposes, and efforts to restore mangroves have surged, along with the tools and knowledge to support such restoration efforts. Mangroves are also remarkably resilient and opportunistic. Give these ecosystems half a chance and they’ll take it – rapidly settling on newly deposited coastal settlements or recolonizing former strongholds whenever they are re-connected to the shifting tides.

Mangroves can be protected through a global, coordinated conservation effort and an expansion of marine protected areas.

The GMA works alongside global partners to safeguard these ecosystems through the advancement of science and understanding, collaboration, information sharing, practical management interventions and the many policy, legal and financial tools that will help to secure a better future for these ecosystems.

Our goal for avoided loss is 16,800 ha by 2030. Rates of mangroves loss have already slowed considerably in recent years. This presents an opportune moment to raise our ambition. While we can aspire to halt all losses, our target refers to direct, and therefore directly manageable, human-driven loss. In recognizing that mangroves are dynamic ecosystems, we also draw attention to the possibility of making further gains as mangroves naturally colonize new locations.	Our goal for restoration is 409,200 ha by 2030. Approximately 818,300 ha are considered restorable and we seek to restore half by 2030. This is a deeply ambitious goal. New work by Worthington and colleagues nonetheless shows that there is enormous potential for restoration, both by estimating the restorability and by highlighting the considerable side benefits for local populations and the global community.	Our goal for doubling protection is 6,100,000 ha under conservation measures. 42% of the world’s mangroves currently in protected areas. However, the urgency to halt all loss is fundamental. One of our key approaches is incorporating of mangroves into permanent forms of protection including traditional protected areas and Other Effective Area-based Conservation Measures (OECMs), which could encompass indigenous lands and areas of sustainable use.

While mangrove losses in the past were considerable, rates of loss are declining and fell by 44% between 2000 and 2020. In addition, the global picture of mangrove extent is better than ever thanks to the latest Global Mangrove Watch dataset—offering a sixfold increase in mapping resolution and coverage of six additional regions with mangroves.

SOWM 2024

SOWM 2022

SOWM 2021

CURRENT STATE

The latest maps on the Global Mangrove Watch, v4.0, use both optical and radar satellite data and the extent maps have been iteratively improved through the incorporation of user feedback. It has become increasingly apparent that many countries lack good quality national maps. GMW v4.0 now prioritizes resolution for global datasets that are locally relevant and the overall accuracy of the GMW v4.0 map is estimated to be 95.3%.	The conversion of mangroves for aquaculture, oil palm plantations and rice cultivation accounted for 43.3% of global mangrove loss between 2000 and 2020. Natural retraction—changes or losses of mangroves that are driven by movements in riverbeds, sediment inputs, or sea levels—accounted for 26% of the total loss over the 20-year period.	Mangrove threats from human activities are being exacerbated by climate change, especially sea-level rise and more severe and frequent cyclonic weather events. The Global Red List of Mangrove Ecosystems shows that 18 mangrove provinces are threatened, representing ~50% of the world’s mangrove area. More frequent and severe cyclonic storms and sea-level rise, resulting from climate change, threaten one third of the mangrove provinces assessed.

Local ecological knowledge (LEK) can provide vital information to develop mangrove conservation and restoration efforts with greater potential for long-term outcomes. Engaging ethically with LEK may seem a challenge, but thorough guidance is now available for researchers and practitioners through The LEK Best-Practice Guide.

LOCAL ECOLOGICAL KNOWLEDGE

LEK GUIDE

Until recently, we lacked a global estimate of the fish and invertebrate productivity associated with the presence of mangrove forests. But new data on the density of 37 species of fish, prawns, crabs and one cockle species from locations around the world, estimated that the presence of mangroves annually supports nearly 800 billion fishes and invertebrates.	The clearance of vast tracts of mangroves for aquaculture is well documented. Restoration must be accelerated but many challenges remain. For shrimp, demand will continue. Efforts to reduce consumer demand may help along with new approaches to aquaculture, including Associated Mangrove Aquaculture (AMA). Once established, the AMA provides both food and shelter for aquatic species to grow and thrive as part of the natural food web.	A key component of ongoing mangrove management is ensuring local communities can be engaged in a sustainable manner, benefiting from mangroves. Where growing populations and diminished mangroves coincide, opportunities for increasing the sustainability of traditional or modern practices may be required, as well as new opportunities within or beyond the mangroves such as fishing, salt production, sustainable timber harvesting, beekeeping and tourism.

Our ambitions are high and our impacts must be higher if we are to accomplish our 2030 Goals. Through the collective efforts of global and local partnerships, we can ensure that mangroves, and everything that depends on them, survive and thrive.