Blue carbon: an environmental powerhouse
Blue carbon is captured by the oceans and along the coasts. Recent global data estimates that vegetated coastal habitats, like those surrounding Port Phillip Bay and in particular Western Port, contribute to 50% of carbon buried in the marine environment.
Our coastal vegetation saves carbon at a rate 35-57 times faster than tropical rainforests, and holds carbon for millennia while our forests can only store carbon for decades.
It’s a powerhouse worth protecting.
- Seagrass beds comprise 54% of the carbon stocks in Port Phillip Bay and more particularly Western Port, which is dominated by extensive seagrass.
- Saltmarsh comprises 31% of the carbon stocks in the bays. The highest values recorded were at Hastings, Rhyll Inlet, Warneet, West Gate Bridge and Yaringa.
- Mangroves represent the smallest proportion of the carbon stock in Port Phillip Bay and Western Port at 15%.
- An emerging trend shows areas higher in the estuaries, including under West Gate Bridge and at Rhyll Inlet, have higher carbon stocks.
Degradation and loss of vegetated coastal habitats as a result of population pressures, land clearing, animal grazing and poor management could shift these areas from being carbon storage containers to carbon emitters.
Urban development at a number of locations also means there is no room for saltmarsh and mangroves to move shoreward with sea-level rise .
There are a number of ‘at risk’ locations or large areas of habitat that could be restored to their pre-European condition, including sections of north-western Port Phillip Bay and much of the northern coastline of Western Port.
For example, at Lang Lang in north-eastern Western Port, a large bank is eroding and it appears to be very vulnerable to losses of sediment-stored carbon stock.
We need to make smart decisions now to save our blue carbon powerhouses into the future.
For more information, please read the full paper.