Mangroves – trees and shrubs that live in intertidal zones – are found along tropical and sub-tropical coastlines. Mangrove forests form a unique wetland ecosystem, inhabiting the edge of land and sea, rooted and thriving in seawater.
Mangroves play a vital role in coastal ecology and in sustaining and securing coastal communities. They reduce the harmful effects of coastal erosion, storms and flooding and are one of the most cost-effective methods of managing disaster risk along coastlines.
Mangroves provide a safe nursery – food and protection – for young marine life before they are ready to move further out to sea or populate coral reefs. As well as supporting and protecting marine life, mangroves provide nesting and migratory sites for hundreds of species of birds which flourish among their branches.
Mangroves make a critical contribution to climate regulation through carbon capture. Unlike terrestrial forests, which store most of their carbon in the trunk and branches, mangroves store most carbon in their root systems and neighbouring soil – acting as carbon ‘sinks’, locking it away for generations. Also, unlike terrestrial forests, the risk of fire – and the accompanying loss of stored carbon – is much less likely to occur, making them a safe long-term carbon ‘investment’.
Economically, mangroves provide livelihood opportunities for coastal communities through fisheries and ecotourism. The fish, shellfish and other food sources obtained from them play a vital role in the food security of neighbouring communities.
Several Commonwealth countries have globally-significant mangrove coverage, so action taken to protect and restore them in the Commonwealth is good for the world.
of global mangrove cover has been lost over the last 50 years
Despite their importance, mangrove ecosystems are under extreme pressure from human activity. Mangrove trees are being cut back for firewood, coastal development and to make way for shrimp farming. They are falling victim to pollution from inland sources such as discarded plastics, untreated sewage and nutrients from agriculture.
When mangrove forests are cut, they release stored carbon into the environment. Blue carbon emissions have increased significantly as a result of mangrove deforestation.
Mangrove losses for the period 1980–2005 are estimated to be more than 3 million hectares. It is crucial to restore and enrich them.
of mangrove loss is attributed to the development of palm oil plantations and rice paddy crops from 2000 to 2012
Mangroves absorb and store three to four times more carbon than terrestrial forests
different species of mangrove tree
value of mangroves per hectare per year to the national economies of developing countries that host mangroves
Sri Lanka has stepped forward to be a Commonwealth Blue Charter Champion and lead an Action Group on Mangrove Restoration. The country is home to nearly 16,000 hectares of mangroves. It has taken a number of significant measures to conserve and manage mangroves in order to safeguard biodiversity and the contribution of mangroves to the ecosystem.
The Mangrove Restoration Action Group shares best practices and organises mutual co-operation in the conservation and sustainable utilisation of mangroves in the Commonwealth through:
- developing a database on mangrove ecosystems in the Commonwealth;
- sharing technical know-how on valuing the economic contribution of mangroves to coastal livelihoods through fishing and ecotourism;
- creating strategies to strengthen legal frameworks for conservation of mangroves;
- strengthening community partnerships for the management and resource ownership of mangrove ecosystems; and
- declaring protected mangrove areas to ensure legal protection.
Case studies
Lessons From the Restoration of a Mangrove System in Point Lisas, Trinidad and Tobago
Significant impacts on the mangroves in Trinidad and Tobago date back to the 1780s, when the St Ann’s River was diverted and wetlands were reclaimed to expand the city of Port of Spain. Development of roads, housing, industries and other infrastructure along the coast has contributed to the decline of the mangrove forest.
Since 2001, Trinidad and Tobago has had in place a National Policy and Programmes on Wetland Conservation. This includes the concept of “no net loss” of wetlands, their values and their functions on publicly owned lands and waters, and requires mitigation action where mangroves have been removed or adversely affected as a result of development works.
This case study shares the experience of a restoration project in the vicinity of Point Lisas Industrial Park, initiated in 1999. A historic case study is useful to show how a situation has played out – giving the benefit of hindsight to draw lessons. This example shows that the key success factor for this mangrove restoration project was not the planting but rather the restoration of the hydrology in the area to create the right conditions for natural colonisation and recovery.
More information:
- ‘Full Economic Potential of Carbon-Rich Mangroves Remains Untapped’
- ‘Mangroves forests: threats’
- Extinction of mangrove forests (threats: climate change, logging, coastal development, climate change)
- Global Mangrove Alliance
- MangroveWatch, Australia
- Mangrove Action Project
- ‘How does the law protect mangroves in Fiji?
- UNESCO – mangroves
- Mangroves as a line of defense
