Why protecting & restoring blue carbon ecosystems matters

We work to protect and restore coastal ‘blue carbon’ ecosystems for the sustainable provision of ecosystem services to people and environment.

Mangroves and seagrass meadows are coastal ecosystems that cover a small portion of the total ocean area but collectively are widely distributed on every continent except Antarctica. Mangroves are found in 123 countries worldwide with an estimated area of 15.2 million hectares while seagrasses occur in 159 countries covering over 30 million hectares. These ecosystems are highly productive and form biologically rich habitats that play a major role in providing highly valuable ecosystem goods and services for human well-being. For instance, seagrasses cover only 0.1 per cent of the ocean floor but provide valuable nursery habitat to one fifth of the world’s largest fisheries and store up to 18 per cent of the world’s oceanic carbon. Mangroves are some of the most carbon-rich ecosystems on the planet, storing on average 1,000 tonnes of carbon per hectare in their biomass and underlying soils. In addition to their carbon storage benefits and their role in reducing the risks and impacts of climate change; these ecosystems support healthy fisheries, improve water quality, and provide coastal protection against floods and storms.

Experts estimate mangroves to be worth at least US$1.6 billion per year in ecosystem services with a worth of US$33,000-57,000 per hectare per year. It is estimated that more than 1 billion people are within 100 km of seagrass meadows and 100 million people live within 10 km of significant mangrove areas.

In spite of their importance to people, mangroves and seagrasses are amongst the coastal ecosystems that face the highest rates of loss globally, with estimated annual losses of 1–3% of mangroves area and 2–5% seagrass area. Over a quarter of the original mangrove cover has already been lost and almost 30 per cent of global seagrass area has been lost since the late nineteenth century. The main cause of decline for these ecosystems include conversion for aquaculture, agriculture, plantations, coastal development, overharvesting, agricultural and industrial run-off, and climate change.

UNEP is contributing to reversing this trend by promoting international cooperation on the issue, promoting science-based and ecosystem-based management approaches, supporting regional and global assessments, developing best practice manuals and supporting conservation and restoration projects on the ground. To this end, we work with a wide variety of stakeholders and partners that help protect these coastal ecosystems including but not limited to:

Related Sustainable Development Goals