5 reasons we need mangroves

Mangroves are resilient trees and shrubs that thrive where land meets sea, protecting coastlines, waters and the air we breathe. Despite their critical role, more than half of the world’s mangroves are at risk due to agriculture, climate change and more. Efforts to reverse this are vital, as their loss could devastate ecosystems and communities. Fortunately, countries like Kenya, Madagascar and Pakistan have begun restoring their mangrove cover.

Why does mangrove survival matter?

In a world increasingly ravaged by coastal flooding, mangroves stand as a crucial frontline defence. They can reduce flood depths from storms by up to 70 percent, cut cyclone wave heights in half and dampen wave force by 70 percent – saving lives and livelihoods.

Their microorganisms make the soil more cohesive and their tangled roots bind it further. This slows the flow of water which would wear away the shore. By trapping sediments and stabilising the shoreline, mangroves build up the land, resisting slight sea level rises.

Mangroves are mighty carbon sinks, storing five times more CO₂ than tropical rainforests. Their unique saline environment also produces far less methane than freshwater wetlands, making them vital allies in combating climate change.

Their waterlogged, oxygen-poor soil slows the breakdown of organic material, locking away carbon for centuries, perhaps millennia. If destroyed, an estimated six billion tons of carbon – equivalent to a year of US emissions – would be released.

Mangroves also benefit local residents by providing shade, increasing humidity and reducing air pollution by trapping particles from industrial processes.

Mangroves support nearly 800 billion fish and invertebrates annually, along with birds and animals ranging from tigers in Bangladesh to terrapins in Cambodia.

Biodiversity is critical to the planet. Ecosystems with a variety of plants and animals are more stable, and more able to resist environmental stresses such as pests and diseases.

When natural habitats like mangroves are destroyed, humans are brought into closer contact with wildlife, increasing the risk of zoonotic disease outbreaks. Healthy ecosystems buffer us from pathogens, reducing the likelihood of pandemics like COVID-19 and Ebola. Protecting mangroves is not just about conservation but global public health.

Sewage plants, fertiliser runoff into rivers and farmed soil getting washed into water can cause algal blooms. These toxic patches of discoloured water suck out oxygen, killing sea creatures and plants.

Mangroves act as a natural water treatment system. They absorb nitrogen, phosphorus and other causes of excessive algae from human and natural sources.

Microorganisms around their roots break down pollutants like the heavy metals found in some pesticides and fertilisers. The dense root network stops debris from flowing into the sea and harming marine life. Coral reefs and seagrass beds near mangroves grow better, in turn contributing immensely to environmental health: supporting biodiversity, sequestering carbon and providing protection and economic benefits to humans.

Mangrove trees provide valuable resources including timber, fuel, charcoal, fruit and medicines. Their tannins make dye and leather, while their reeds can be crafted into bags and mats. Their roots shelter fish and crabs. Bees make their home in the branches and cattle graze on their fodder.

Economically, mangroves reduce disruption after cyclones, with flood protection benefits exceeding $65 billion per year.

They attract tourism for boating and birdwatching, supporting local businesses. In Gujarat, India, women have worked with the Aga Khan Foundation (AKF) to reforest 20 hectares of land, using it for sustainable animal feed and fuel. In Cabo Delgado, Mozambique, women are learning beekeeping, mangrove restoration and financial literacy as part of AKF’s Mel do Mar programme, which also helps them sell honey and build savings groups.

Mangroves have become a modern economic asset. In Kenya, Gazi Bay residents restore and protect enough mangroves to earn $12,000 a year in carbon credits, reinvested in local education and healthcare projects. And Pakistan, which has tripled its mangrove cover over the last three decades, is projected to earn $12 billion in carbon credits by 2075.