Putting a value on marine life

As humanity strives to avoid dangerous changes to climate and keep carbon emissions at bay, the value of ecosystems that act as carbon sinks could become increasingly important. A preliminary report released at the Eye on Earth Summit shows the importance of mangroves, saltwater marshes and sea-grass beds as carbon sinks, and reinforces the need to protect them. "About 70 per cent of the global ocean's capacity to store carbon is in mangroves, saltwater marshes and sea grass beds," said Dr Peter Prokosch, the managing director of GRID-Arendal, an initiative of the UN Environment Programme. This week, the agency and the International Union for Conservation of Nature produced a feasibility study for the Arabian Peninsula on behalf of the Abu Dhabi Global Environmental Data Initiative. The report summarises attempts by scientists to account for the amount of carbon sequestered by mangroves - an average of 3,754 tonnes a hectare. Each hectare of saltwater marshes trap between 900 and 1,700 tonnes of carbon dioxide, while a hectare of sea-grass meadows capture 766.5 tonnes, the report says.