Blue carbon stocks of Great Barrier Reef deep-water seagrasses, York et al. 2018

Compendium Volume 3 Number 1 July 2019

The Great Barrier Reef (GBR) protects northeast Australia from wave exposure, while also creating habitat for a vast expanse of shallow- and deep-water seagrasses between the reef and the shoreline. Deep-water seagrasses here occupy an area roughly the size of Switzerland. While the carbon storage capacity of shallow-water seagrasses, dubbed ‘blue carbon,’ are known to be extremely high, the amounts of carbon stored in deep-water seagrasses (greater than 15 meters depth) is less well known, and expected to be lower due to these plants’ smaller stature and relative sparseness.

The authors found, however, that “deep-water seagrass contained similar levels of organic carbon (OC) to shallow-water species, despite being much sparser and smaller in stature” [York 2018: 1]. Furthermore, deep-water seagrass sediments contained about nine times more OC than surrounding bare areas.

If the OC stocks reported in this study are similar to deep-water [seagrass] meadows elsewhere within the GBR lagoon, then OC bound within this system is roughly estimated at 27.4 million tons [York 2018: 1].

York, Paul H., Peter I. Macreadie & Michael A. Rasheed, 2018, Blue Carbon stocks of Great Barrier Reef deep-water seagrasses, Biological Letters 14,

For the full PDF version of the compendium issue where this article appears, visit Compendium Volume 3 Number 1 July 2019