European countries are big on protecting their seagrass eco systems. Sailing all through the Mediterranean i had never taken the time to understand why we shouldn’t anchor areas of seagrass or in anyway damage seagrass. On our recent cruise north to Queensland then penny finally dropped, and i learnt why its so important to preserve this important habitat…my bad it took me so long.
We all know that the release of carbon dioxide into our atmosphere is a major contributor to climate change. Likewise we know that our trees and forests act as carbon sinks, sucking carbon out of the atmosphere and capturing or holding it in a process called sequestration.
It turns out that trees and forests are called green carbon ecosystems, and while incredibly important, they aren’t nearly as efficient at storing carbon as their blue carbon ecosystem counterparts…
Over the past decade, scientists have discovered that some of our under-appreciated coastal habitats now called “blue carbon ecosystems” play a huge role in tackling carbon dioxide emissions. Blue carbon ecosystems include mangroves, seagrass meadows and tidal wetlands and are named for their place at the boundary between land and sea, and their unmatched ability to suck CO2 out of the atmosphere and store it in the ground below.
Coastal seagrass can store more carbon per square kilometre than forests can, which means these coastal plants could be part of the solution to climate change. In fact recent research indicates that seagrasses can hold up to 83,000 tonnes of carbon per square kilometre – that’s nearly three times the 30,000 tonnes of carbon per square kilometre a typical forest can store.
Forest carbon stores are limited to the lifetime of the trees, for only 100 or so years, once the tree is cut down and, for example burnt, the carbon is then released back into the atmosphere. Trees also store 80% of their carbon above ground in the trunk and canopy, as the seagrasses and mangroves take up and store carbon dioxide in their soils and biomass the carbon is locked in the soils for millennia, so long as the seagrass ecosystems remain intact.
So losing seagrass is a double whammy for our environment’s health – not only do we lose the plant’s ability to capture and store CO2, all the CO2 that’s already being stored gets released back out into the ecosystem.
The bad news is that like everything else in the ocean, seagrass is sensitive to rising sea temperature’s. It is also easily damaged by coastal development – its a habitat under pressure and already somewhere between 25% and 50% of the worlds blue carbon eco- systems have been destroyed. The good news is that there is now a growing research industry working out the most effective way to restore and replenish our seagrass and mangrove habitats.
Spread the word – our ocean’s and coast’s provide a natural way of reducing the impact of greenhouse gases. It is vitally important that, along with our Green Carbon assets of forests and trees we do more to protect, restore and replenish our blue carbon ecosystems of mangroves and seagrass beds.