|Photo de Peter Facey (Wikimedia Commons)|
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.
This was the central message delivered by the United Nations Environment Programme (UNEP) and the International Union for the Conservation of Nature (IUCN) during an event held by the Convention on Biological Diversity (CBD) in Montreal.
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, explains Dr. Gail Chmura, a coastal researcher at McGill University, who spoke at the UNEP side event.
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, notes Chmura.
Studies by her research group show that ecological functions of drained marshes can be restored, along with the carbon sink.
In fact, Chmura and colleagues have calculated that the restoration of Canada's drained agricultural marshes will provide ecosystem services worth $14,535 per hectare and a renewed sink for carbon dioxide equivalent to 6 per cent of Canada's original commitment for reductions under the Kyoto Protocol.
UNEP and IUCN note that the degradation of coastal ecosystems means more than just a reduction in the amount of carbon they store. Other ecosystem services provided by seagrasses 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.
UNEP’s Blue Carbon Initiative supports scientific research into blue carbon in coastal ecosystems as well as the valuable ecosystem services they provide. UNEP also supports economically viable projects that monetize carbon and ecosystem services in order to better manage these coastal ecosystems. The Blue Carbon Initiative has thus far supported research into blue carbon in critical ecosystems in Africa, and has raised the profile of blue carbon globally with various reports and scientific conferences.
The event also highlighted 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.
Source: PNUE (UNEP)