Reversing the degradation of coastal ecosystems in Canada and elsewhere can play an important role in tackling climate change, while bringing additional benefits to biodiversity and the economies of coastal communities.

From Canada to Cancun, coastal ecosystems store high levels of carbon in their soil. This so-called "Blue Carbon" is found in tidal salt marshes, grassy meadows subject to the rise and fall of ocean tides, and their tropical cousins, mangrove swamps.Meadows of "sea grasses", permanently submerged by shallow ocean waters, also are important Blue Carbon sinks. All these ecosystems can store carbon dioxide from the atmosphere for millennia, making an important contribution to efforts to tackle climate change.

However, if these ecosystems are degraded, the stored carbon risks being released into the atmosphere as carbon dioxide. Despite Canada's cold climate, the country's salt marshes store as much carbon as in warmer climes. 

But much of the marsh area in eastern Canada, including the coasts of New Brunswick, Nova Scotia and Quebec has been drained for use in agriculture. Ecological functions of drained marshes can be restored, along with the carbon sink.

The restoration of Canada's drained agricultural marshes will provide ecosystem services worth $14,000 per hectare (Approx) and a renewed sink for carbon dioxide equivalent to 6 per cent of Canada's original commitment for reductions under the Kyoto Protocol.

The degradation of coastal ecosystems means more than just a reduction in the amount of carbon they store. Other ecosystem services provided by sea grasses and mangroves, such as protection from storms and tsunamis, habitat for fish and wildlife, support of coastal fisheries, and local livelihoods of coastal inhabitants, are also adversely affected by their decline.

The need for newer and more accurate ways of measuring the carbon stored in coastal ecosystems in Canada and beyond. Such information can support countries in planning national strategies for climate change adaptation and mitigation.