Seagrass restoration enhances "blue carbon" sequestration in coastal waters

PLoS One. 2013 Aug 14;8(8):e72469. doi: 10.1371/journal.pone.0072469. eCollection 2013.

Abstract

Seagrass meadows are highly productive habitats that provide important ecosystem services in the coastal zone, including carbon and nutrient sequestration. Organic carbon in seagrass sediment, known as "blue carbon," accumulates from both in situ production and sedimentation of particulate carbon from the water column. Using a large-scale restoration (>1700 ha) in the Virginia coastal bays as a model system, we evaluated the role of seagrass, Zosteramarina, restoration in carbon storage in sediments of shallow coastal ecosystems. Sediments of replicate seagrass meadows representing different age treatments (as time since seeding: 0, 4, and 10 years), were analyzed for % carbon, % nitrogen, bulk density, organic matter content, and ²¹⁰Pb for dating at 1-cm increments to a depth of 10 cm. Sediment nutrient and organic content, and carbon accumulation rates were higher in 10-year seagrass meadows relative to 4-year and bare sediment. These differences were consistent with higher shoot density in the older meadow. Carbon accumulation rates determined for the 10-year restored seagrass meadows were 36.68 g C m⁻² yr⁻¹. Within 12 years of seeding, the restored seagrass meadows are expected to accumulate carbon at a rate that is comparable to measured ranges in natural seagrass meadows. This the first study to provide evidence of the potential of seagrass habitat restoration to enhance carbon sequestration in the coastal zone.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Carbon / isolation & purification*
  • Carbon / metabolism*
  • Carbon Sequestration*
  • Conservation of Natural Resources*
  • Geologic Sediments / chemistry
  • Seawater / chemistry*
  • Zosteraceae / growth & development*
  • Zosteraceae / metabolism*

Substances

  • Carbon

Grant support

Funding for this study was provided by the National Science Foundation grant DEB-0621014 and DEB-1237733 to the Virginia Coast Reserve LTER project and from the Department of Environmental Sciences at the University of Virginia. This article was published in part thanks to funds provided by the University of Virginia Library Open Access Fund. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.