Sediment carbon storage differs in native and non-native Caribbean seagrass beds

Catherine L Brenner; Stephanie R Valdez; Y Stacy Zhang; Elizabeth C Shaver; Brent B Hughes; Brian R Silliman; Joseph P Morton

doi:10.1016/j.marenvres.2023.106307

Sediment carbon storage differs in native and non-native Caribbean seagrass beds

Mar Environ Res. 2024 Feb:194:106307. doi: 10.1016/j.marenvres.2023.106307. Epub 2023 Dec 18.

Authors

Catherine L Brenner¹, Stephanie R Valdez², Y Stacy Zhang³, Elizabeth C Shaver⁴, Brent B Hughes⁵, Brian R Silliman², Joseph P Morton⁶

Affiliations

¹ Division of Marine Science and Conservation, Nicholas School of the Environment, Duke University, 135 Duke Marine Lab Rd., Beaufort, NC 28516, USA. Electronic address: catherine.brenner@duke.edu.
² Division of Marine Science and Conservation, Nicholas School of the Environment, Duke University, 135 Duke Marine Lab Rd., Beaufort, NC 28516, USA.
³ Division of Marine Science and Conservation, Nicholas School of the Environment, Duke University, 135 Duke Marine Lab Rd., Beaufort, NC 28516, USA; Department of Marine, Earth and Atmospheric Sciences, North Carolina State University, Raleigh, NC 27695, USA.
⁴ Division of Marine Science and Conservation, Nicholas School of the Environment, Duke University, 135 Duke Marine Lab Rd., Beaufort, NC 28516, USA; The Nature Conservancy, 4245 Fairfax Dr. #100, Arlington, VA 22203, USA.
⁵ Sonoma State University, Department of Biology, 1801 E Cotati Ave, Rohnert Park, CA 94928, USA.
⁶ Division of Marine Science and Conservation, Nicholas School of the Environment, Duke University, 135 Duke Marine Lab Rd., Beaufort, NC 28516, USA; Department of Environmental Engineering Sciences, University of Florida, Gainesville, FL, 32611, USA.

PMID: 38150787
DOI: 10.1016/j.marenvres.2023.106307

Abstract

Non-native species are expanding globally and can alter ecosystem functions, including food web dynamics, community structure and carbon storage. Seagrass are foundation species that contribute a variety of ecosystem services in near-shore coastal ecosystems, including a significant sink of carbon. In the Caribbean, the rapidly expanding non-native Halophila stipulacea has unknown impacts on carbon storage. To investigate the impacts on carbon storage, we quantified organic carbon (C_org) content in sediment and seagrass tissues from monotypic H. stipulacea beds, mixed native seagrass beds dominated by Thalassia testudinum and Syringodium filiforme, and unvegetated substrate in St. John, USVI. We found native seagrass-vegetated sediment contained 1.3 times more C_org than sediment covered by H. stipulacea, and 1.6 times more C_org than unvegetated areas on average. Whereas, H. stipulacea-dominated substrate stored 1.2 times more C_org than unvegetated substrate. Likewise, native species contained 2.2 times more aboveground biomass and 6.0 times more belowground biomass than H. stipulacea. Since seagrasses are critical sources of carbon sequestration, our results suggest that invading H. stipulacea is associated with lower carbon stocks which has potential implications for conservation activities and climate change mitigation.

Keywords: Carbon storage; Caribbean; Non-native species; Seagrass.

MeSH terms

Alismatales*
Biomass
Carbon / analysis
Carbon Sequestration
Caribbean Region
Ecosystem*

Substances

Carbon