The World Needs Mangroves

“If there are no mangroves, then the sea will have no meaning. It’s like a tree with no roots, for the mangroves are the roots of the sea!” ~ Mad-Ha Ranwasii, Thai fisherman & village headman, 1992.

The world needs more mangroves, as they have been lost or degraded in many parts of the world, along with their valuable services such as coastal protection and fisheries enhancement. Restoration is not just necessary, it’s a pressing priority in many places.  

Mangrove forests are prolific ecosystems located on the interface between land and sea in the tropics and subtropics.  The trees aresalt-tolerant (halophytes) and adapt to life in harsh coastal conditions. They contain both a complex salt filtration system and complex root system to cope with saltwater immersion and wave action and are adapted to the low-oxygen conditions of waterlogged mud.

Mangrove forests provide critical ecosystem services, contributing an estimated US$42 billion to global fisheries, storing 25.5 million tons of carbon per year, and providing flood protection to over 15 million people annually (Walker at al. 2022). It is estimated that if all the mangroves in the world were lost, 18 million more people would be affected by floods every year on average, an increase of almost 40 %. The annual property damage would increase by US$82 billion.  In Trinidad and Tobago, floods are the most common and widespread of all natural disastersand there is strong evidence that, in a warming world, destructive floods will become more common and intense, adversely affecting the lives of even more people

In addition to providing protection against coastal flooding, mangrove forests have the highest area rates of carbon capture and storage compared with any other ecosystem, terrestrial or marine, contributing disproportionately as a carbon sink, if left undisturbed. On average, mangroves have a mean whole-ecosystem carbon stock around 2.5–5 times higher than the mean ecosystem carbon stock found in temperate, boreal and upland tropical forests (Alongi, 2012).  Initial estimates of carbon stored in the mangrove forests in Trinidad and Tobago are at 1,118,630.99 tonnes. Comparing mangrove forest carbon to terrestrial forest carbon revealed that mangrove forests store 61% more carbon per hectare than terrestrial forests in Tobago. At the same time, for Trinidad, the value was 44% (Juman et al. 2021). The belowground soil carbon pool is estimated to be at least four times more (and likely considerably higher) than the aboveground pool, making mangrove forests amongst the highest carbon dense ecosystems in the world, and providing climate mitigation benefits.

Trinidad and Tobago’s coastlines, especially the Gulf of Paria, were once adorned by these magnificent trees with their intertwined roots teeming with wildlife.  They were hunting grounds for our grandfathers and fathers who sought crabs for the Sunday callaloo and harvested oysters that were sold in spicy sauce around the Queen’s Park Savannah. In Trinidad and Tobago, the mangrove forests not only provide livelihoods for those who harvest and sell fish and shellfish, but they also offer invaluable opportunities for recreation and tourism. They are places where the locals pray and play, and their beauty and biodiversity are truly something to be admired and appreciated. 

Despite their crucial role in coastal protection, climate mitigation and providing livelihood opportunities, mangrove forests were destroyed or degraded by human activities including, but not limited to: pollution; coastal development; extractive activities; unsustainable aquaculture, and agricultural practices (UNFCCC, 2022). Globally, there has been a decline of 1.04 million hectares between 1990 and 2020 (FAO, 2020).  At home, we did not fully understand nor appreciate the importance of these coastal forests, so as much as 50 % were cleared to build houses, businesses and ports.  We must take immediate action now to conserve our remaining mangrove forests and rehabilitate the degraded area. 

To this end, The National Gas Company of Trinidad and Tobago Limited (NGC) has partnered with the Institute of Marine Affairs (IMA), a government marine research institute and other keys partners, to help raise awareness of the importance of mangrove forests and to rehabilitate the degraded mangrove forest in Carli Bay, in the Central Gulf of Paria. NGC, no stranger to environmental preservation projects, having reforested 315 hectares of terrestrial forest, is working with IMA as part of its “Beyond 315” programme, a suite of environmental programmes in advancement of the Company’s Green Agenda, to implement this mangrove restoration project by removing stressors, restoring its natural hydrological regime and if necessary, planting mangrove seedlings.  The project intends to foster sustainable livelihood opportunities through education and capacity development, and stewardship among the coastal communities to sustainably manage their mangrove forest.

As we commemorate the International Day for the Conservation of Mangrove Forests on July 26, IMA and NGC appeal to citizens to be conscious of where their garbage goes. Marine debris from both land-based and sea-based activities, can cause the death of animals that live in the mangroves and suppress their habitats.  Mounds of rubbish in tidal channels can inhibit tidal flushing and increase salinity levels, stressing the habitat and creating spaces for mosquitoes to breed, which can transmit viruses such as dengue.  Plastic waste can be trapped by mangrove trees and can be found on the surface or buried in the sediments. They become immobile and can create prolonged anoxic conditions, changing the physical and chemical composition of sediments.  If we want to rehabilitate degraded mangroves, we must remove all stressors including pollutants such as garbage.  

It is our hope that citizens of Trinidad and Tobago will become meaningfully engaged in mangrove conservation.  Let us value our mangrove forests.  

Prepared by the Institute of Marine Affairs & The National Gas Company of Trinidad & Tobago Limited

References:

Alongi, D. (2012). Carbon sequestration in mangrove forests. Carbon Management3(3), 313–322.

Juman, R., Asmath, H., Gooding, N. and Collins, G. 2021.  Mangrove Forests of Trinidad and Tobago, Institute of Marine Affairs, Chaguaramas, Trinidad and Tobago

Walker, J.E., Ankersen, T., Barchiesi, S., Meyer, C.K., Altieri, A.H., Osborne, T.Z. and Angelini, C., 2022. Governance and the mangrove commons: Advancing the cross-scale, nested framework for the global conservation and wise use of mangroves. Journal of Environmental