Nanaimo Estuary has strong potential for carbon storage

The Nanaimo Estuary is one of the most important estuaries in the province for carbon storage, deemed critical for slowing climate change and absorbing spent carbon.

In a report titled Blue Carbon – British Columbia, authored by Colin Campbell, science advisor for Sierra Club B.C., the Nanaimo Estuary is ranked in the top seven of 442 B.C. estuaries for effective sea burial of carbon because of its high concentration of eelgrass and salt marshes.

“Eelgrass and salt marshes bury carbon for thousands of years where nothing happens, it gets locked down until it gets uncovered,” said Campbell from Australia, where he is visiting mangrove-lined estuaries and other sites protected within a national system of marine protected areas.

“This is probably the most efficient carbon removal mechanism on Earth and the Nanaimo Estuary is right up there because of its size and its salt marshes.”

In comparison, forests, also considered important carbon sinks, bury carbon for hundreds of years, said Campbell.

His report indicates estuaries can be up to 90 times more efficient at storing carbon than the equivalent area of forest, but are disappearing far faster than forests.

That’s prompting Campbell to call for immediate protection of estuaries through federal, provincial and municipal governments. Only 13 per cent of provincial estuaries are protected.

In B.C., estuary habitats sequester a minimum of 180,000 tonnes of carbon annually, enough to balance the emissions of 200,000 passenger cars.

Eelgrass absorbs carbon from water while salt marshes absorb it from the atmosphere. In the Nanaimo Estuary, a project to replenish eelgrass has been ongoing for three years.