Primary Research Article
Net uptake of atmospheric CO2 by coastal submerged aquatic vegetation
Article first published online: 13 MAR 2014
© 2014 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.
This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.
Global Change Biology
Volume 20, Issue 6, pages 1873–1884, June 2014
How to Cite
Tokoro, T., Hosokawa, S., Miyoshi, E., Tada, K., Watanabe, K., Montani, S., Kayanne, H. and Kuwae, T. (2014), Net uptake of atmospheric CO2 by coastal submerged aquatic vegetation. Global Change Biology, 20: 1873–1884. doi: 10.1111/gcb.12543
- Issue published online: 9 MAY 2014
- Article first published online: 13 MAR 2014
- Manuscript Accepted: 30 DEC 2013
- Manuscript Received: 8 AUG 2013
- Canon Foundation
- Challenging Exploratory Research. Grant Number: 24656316
- Japan Society for the Promotion of Science
- air–water CO2 flux;
- blue carbon;
- carbon cycles;
- climate change;
- net ecosystem production;
‘Blue Carbon’, which is carbon captured by marine living organisms, has recently been highlighted as a new option for climate change mitigation initiatives. In particular, coastal ecosystems have been recognized as significant carbon stocks because of their high burial rates and long-term sequestration of carbon. However, the direct contribution of Blue Carbon to the uptake of atmospheric CO2 through air-sea gas exchange remains unclear. We performed in situ measurements of carbon flows, including air-sea CO2 fluxes, dissolved inorganic carbon changes, net ecosystem production, and carbon burial rates in the boreal (Furen), temperate (Kurihama), and subtropical (Fukido) seagrass meadows of Japan from 2010 to 2013. In particular, the air-sea CO2 flux was measured using three methods: the bulk formula method, the floating chamber method, and the eddy covariance method. Our empirical results show that submerged autotrophic vegetation in shallow coastal waters can be functionally a sink for atmospheric CO2. This finding is contrary to the conventional perception that most near-shore ecosystems are sources of atmospheric CO2. The key factor determining whether or not coastal ecosystems directly decrease the concentration of atmospheric CO2 may be net ecosystem production. This study thus identifies a new ecosystem function of coastal vegetated systems; they are direct sinks of atmospheric CO2.