Blue carbon refers to the carbon accumulation capacity of vegetated coastal habitats, including salt marshes, mangroves forests and seagrass meadows. Here we present estimates of organic carbon (C-org) and calcium carbonate (CaCO3) burial rates from 4 seagrass species (Halophila ovalis, Posidonia australis, Ruppia megacarpa, Zostera muelleri) in 3 temperate estuaries on the east coast of Australia. The C-org burial rates (mean +/- SE) varied by an order of magnitude across the seagrass communities (16 +/- 3 to 130 +/- 40 g m(-2) yr(-1)). The delta C-13(org) and C-org:N ratios suggest that the seagrass communities buried variable mixtures of seagrass, algal and mangrove/terrestrial material. CaCO3 burial rates ranged from 15 +/- 11 to 188 +/- 122 g m(-2) yr(-1), which, if precipitated by calcifying organisms in these or nearby habitats, may offset up to 89% of the C-org burial across the 8 seagrass communities. Our results highlight a large range in both C-org and CaCO3 burial rates, and the provenance of the carbon sequestered in seagrasses, factors that need to be considered when assessing the role of seagrasses in blue carbon and climate change mitigation strategies.
1.Southern Cross Univ, Natl Marine Sci Ctr, Sch Environm Sci & Engn, POB 4321, Coffs Harbour, NSW 2450, Australia 2.Southern Cross Univ, Southern Cross Geosci, POB 157, Lismore, NSW 2480, Australia 3.Univ S Florida, Environm Sci, St Petersburg, FL 33701 USA 4.Southern Cross Univ, Ctr Coastal Biogeochem Res, Sch Environm Sci & Engn, Lismore, NSW 2480, Australia
Recommended Citation:
Sanders, Christian J.,Maher, Damien T.,Smoak, Joseph M.,et al. Large variability in organic carbon and CaCO3 burial in seagrass meadows: a case study from three Australian estuaries[J]. MARINE ECOLOGY PROGRESS SERIES,2019-01-01,616:211-218