Carbon storage in the seagrass meadows of Gazi Bay, Kenya

Githaiga, Michael N.; Kairo, James G.; Njoroge Githaiga, Michael; Gitundu, Kairo; Gilpin, Linda; Huxham, Mark

Abstract

Vegetated marine habitats are globally important carbon sinks, making a significant contribution towards mitigating climate change, and they provide a wide range of other ecosystem services. However, large gaps in knowledge remain, particularly for seagrass meadows in Africa. The present study estimated biomass and sediment organic carbon (Corg) stocks of four dominant seagrass species in Gazi Bay, Kenya. It compared sediment Corg between seagrass areas in vegetated and un-vegetated ‘controls’, using the naturally patchy occurence of seagrass at this site to test the impacts of seagrass growth on sediment Corg. It also explored relationships between the sediment and above-ground Corg, as well as between the total biomass and above-ground parameters. Sediment Corg was significantly different between species, range: 160.7–233.8 Mg C ha-1 (compared to the global range of 115.3 to 829.2 Mg C ha-1). Vegetated areas in all species had significantly higher sediment Corg compared with un-vegetated controls; the presence of seagrass increased Corg by 4–6 times. Biomass carbon differed significantly between species with means ranging between 4.8–7.1 Mg C ha-1 compared to the global range of 2.5–7.3 Mg C ha-1. To our knowledge, these are among the first results on seagrass sediment Corg to be reported from African seagrass beds; and contribute towards our understanding of the role of seagrass in global carbon dynamics.

Citation

Githaiga, M. N., Kairo, J. G., Njoroge Githaiga, M., Gitundu, K., Gilpin, L., & Huxham, M. (2017). Carbon storage in the seagrass meadows of Gazi Bay, Kenya. PLOS ONE, 12(5), Article e0177001. https://doi.org/10.1371/journal.pone.0177001

• Journal Article Type: Article
• Acceptance Date: Apr 21, 2017
• Online Publication Date: May 10, 2017
• Publication Date: May 10, 2017
• Deposit Date: Apr 25, 2017
• Publicly Available Date: May 12, 2017
• Journal: PLoS One
• Print ISSN: 1932-6203
• Publisher: Public Library of Science
• Peer Reviewed: Peer Reviewed
• Volume: 12
• Issue: 5
• Article Number: e0177001
• DOI: https://doi.org/10.1371/journal.pone.0177001
• Keywords: Sediment, Biomass (ecology), Carbon sink, Carbon sequestration, Ecosystems, Mangrove swamps, Coastal ecosystems, Marine,
• Public URL: http://researchrepository.napier.ac.uk/Output/832168
• Contract Date: May 12, 2017