2019_programme: ACOUSTIC SENSING OF BLUE CARBON STORES: A PILOT STUDY

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  • Session: 03. Acoustic Monitoring of Ocean Environments and Processes: Biology, Ecology, Geophysics and Man-made activities
    Organiser(s): Ratilal Purnima, Miksis-Olds Jennifer
  • Lecture: ACOUSTIC SENSING OF BLUE CARBON STORES: A PILOT STUDY
    Paper ID: 937
    Author(s): Venegas Gabriel R., Rahman Abdullah F., Lee Kevin M., Ballard Megan S., Wilson Preston S.
    Presenter: Venegas Gabriel
    Presentation type: oral
    Abstract: Seagrass meadows, mangroves, and salt marshes cover less than two percent of the ocean’s surface area, but account for half of the total carbon sequestered in ocean sediments. The protection and monitoring of these ecosystems are considered vital in mitigating climate change. Sediments with high organic carbon content generally have been shown to be porous and fine-grained. Sediment acoustic properties are sensitive to porosity and grain size, yet have not been directly correlated to total organic carbon (TOC). A pilot study to explore this relationship was conducted in a Thalassia testudinum seagrass meadow located in a hypersaline lagoon on the Gulf of Mexico Coast of Texas, USA. Sediment cores were collected, acoustically logged in the laboratory, sectioned, and analyzed for sediment properties such as density, porosity, mud content, and TOC. At 300 kHz, results show a highly correlated relationship between sediment primary wave (p-wave) modulus and TOC, pointing to an acoustic sensitivity to blue carbon that can be exploited to rapidly quantify and monitor blue carbon stores. In fact, p-wave modulus correlated better with TOC than with properties relating to the mineral composition, such as mean grain size and mud content. A theory explaining these results will be discussed within the framework of a physical acoustic sediment model, incorporating concepts from biogeochemistry. [Work supported by ONR and ARL:UT IR&D]
  • Corresponding author: Dr Venegas Gabriel R.
    Affiliation: Applied Research Laboratories and Walker Dept. of Mech. Eng., The University of Texas at Austin
    Country: United States
    e-mail:

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