International Day for the Conservation of the Mangrove Ecosystem July 26, 2024
International Day for the Conservation of the Mangrove Ecosystem July 26, 2024
Ms Olfa SEHLI
Marine Ecologist
Sahara and Sahel Observatory
For over 50 million years, mangrove forests settled along tropical and subtropical coasts, and produced a one-of-a-kind space where 80 species of halophilic plants, shrubs, palm trees and ferns intersect, forming an area of transition between land and sea called ecotone. They represent a particular form of evolution and survival on Earth. In fact, thanks to their roots anchored deeply in water, mangroves flourish in hot, muddy and salty environments where no other plant would survive.
In recognition of the importance of mangroves, an International Day dedicated to their conservation was proclaimed by the General Conference of the United Nations Educational, Scientific and Cultural Organization (UNESCO) in 2015, to raise awareness of their crucial role as a unique ecosystem, and to identify solutions for their management, conservation and sustainable use.
Where do mangrove forests grow and why do they draw such international widespread attention?
Mangroves cover 14.8 million hectares, unevenly distributed across the world, with over 6.48 million hectares located in South and Southeast Asia, 2.82 million hectares in Africa, 2.14 million hectares in South America, 1.85 million hectares in North and Central America and 1.46 million hectares in Oceania, with smaller areas in other parts of tropical Asia and Africa.
These coastal ecosystems provide a wide range of services, environmental benefits and important cultural and socio-economic values to local communities. Indeed, they are essential for stabilizing coastlines, mitigating the effects of waves and winds on the coasts and standing as hedges protecting interior structures. Additionally, mangrove vegetation and surrounding sediments serve as essential carbon reservoirs, capturing approximately 22.8 million metric tons of carbon per year[1] and thereby helping mitigate the effects of climate change. Mangroves are also among the most productive ecosystems, providing habitat for a wide diversity of fauna and flora, serving as spawning areas and nurseries, protection zones and sources of food.
Furthermore, mangroves are a vital asset for the survival of local communities for they provide essential services for their livelihood and well-being. According to the “State of the World's Mangroves (2021)” report, nearly 4.1 million fishermen depend on this ecosystem thanks to the 600 billion shrimp and fish and the 100 billion crabs and bivalves it produces. Local communities also take advantage of the resources offered by mangroves for rice farming, pearl farming, logging, energy production and ecotourism.
Mangroves in Africa
According to the FAO “The World's Mangroves 2000–2020” report published in 2020, Africa, having the second largest area of mangroves among the five global regions after Asia, holds 19% of the world's mangroves. 74% of them are located in West and Central Africa. According to “Global Mangrove Watch”, the largest mangrove forests on the African continent are found in Nigeria with 844,200 hectares. These forests are among the most diverse and productive in the world and are known by their high abscission that promotes significant microbial activity. Although they make up only about 5% of the world's mangroves, Nigeria's mangrove forests contribute about 25% of global organic production, with a primary production rate of 24 tons per hectare per year.
In Guinea-Bissau, more than 80% of the population depends on agriculture for their livelihoods. 45% of the land used for rice-growing is located in mangrove rice fields. This reliance does not limit to rice growing but to energy production (for lighting and cooking). Additionally, honey harvested from mangrove forests has a very distinctive taste and unique medicinal benefits.
Threats and the immediate need to restore mangroves and to take adequate conservation measures
Even though they have proven to be highly important, mangrove ecosystems are experiencing a worrying decline. According to “The World's Mangroves 2000-2020” assessment, the global area of mangroves decreased by 284,000 hectares during this period due to several natural phenomena like changing sedimentation rates, rising sea level and changes in temperature and rainfall, in addition to the impact of human activity such as agriculture, the development of aquaculture (26.7%) and the conversion of certain forests into oil palm plantations and rice fields.
According to the same assessment, agriculture, extensive urbanization and intensive logging are the main causes of the destruction of mangroves in Africa. These combined factors have resulted in the loss of nearly 1.7% of the mangrove extent between 2000 and 2020. Although this figure might seem insignificant, it represents a worrying reduction for such a fragile ecosystem, putting biodiversity and the livelihoods of coastal communities at risk.
With this alarming situation, conservation and restoration efforts are more essential than ever before, although their implementation is not possible on all coasts. Indeed, the restoration potential varies depending on the initial and current state of the habitat, and its degree of loss. Hence the need to think of a holistic strategy that considers socio-economic, ecological and cultural aspects for successful restoration. Remember that despite their importance and the amount of investments, many restoration projects failed because of the absence of one or more of these elements. To support these projects and make sure they are successfully implemented, many international Organizations, such as the Global Mangrove Alliance, have provided various guidance materials, such as restoration potential maps and best practice guides. These guides highlight, once again, that the lack of technical and scientific expertise in the restoration process can compromise any project.
What actions are being taken? What can we do to strengthen conservation measures?
In 2023, 97 countries have integrated coastal and marine ecosystems, including mangroves, into their Nationally Determined Contributions (NDCs) under the Paris Agreement and 61 have integrated the conservation and/or restoration of blue carbon ecosystems into their mitigation and adaptation strategies. It was recognized that mangroves are crucial to achieving various targets of the Kunming-Montreal Global Biodiversity Framework, including targets 1, 2, 3 and 8 and that Parties needed to align with the GBF targets at COP16 in 2024.
In recent years, several African countries have made significant progress in the recognition and management of mangroves. In its revised Nationally Determined Contribution (NDC), Mozambique plans to restore 5,000 hectares of mangroves by 2025, acknowledging their crucial role as breeding and feeding grounds for fish. Kenya and Tanzania have also included mangroves in their NDCs, restating their commitment to protecting these vital ecosystems. At the same time, Madagascar is in the process of updating its 2016 NDC, which already recognized the importance of mangroves. These initiatives come to reflect a growing awareness and a stronger commitment to the conservation and restoration of mangroves across the continent, and reflect the shared desire to establish a framework for exchange and improve policies related to the sustainable management of these ecosystems.
Natural capital accounting can also be a valuable asset, helping quantify and value ecosystem services, inform policy and decision-making and ultimately, enable local communities to make the best of ecotourism.
Fully aware of the situation and keen to restore this precious ecosystem, the Sahara and Sahel Observatory is coordinating the “Adaptation of agricultural production systems in the coastal areas of North-West Guinea-Bissau” project, financed by the Green Climate Fund and aimed at restoring 250 hectares of mangrove areas and protecting coastal communities, rehabilitating wetland ecosystems and improving the resilience of mangrove rice farmers.
Mangroves are irreplaceable ecosystems that provide essential environmental, socio-economic and cultural services. Their decline, exacerbated by urbanization, agriculture and climate change, seriously threatens the biodiversity and resilience of coastal communities. The laudable and undeniable conservation and restoration efforts call for a holistic approach that integrates socio-economic and ecological aspects. Furthermore, it is imperative to translate international commitments into concrete and sustainable actions for the well-being of these vital ecosystems.
[1] Towards a framework for mangrove restoration and conservation in Nigeria