Acoustic reflection and scattering from the seabed are highly dependent on how biological communities modify the physics of seafloor sediment. In this project, we will establish baseline information on how organisms that live in the sediment affect the acoustic properties of the seafloor.
Ocean bottom sensing using acoustics is critically important to naval operations, such that an incorrect or inaccurate sediment characterisation can have a substantive impact on operations and planning. A significant challenge in characterising the seafloor is that acoustic reflection and scattering from the seabed are highly dependent on both biological and geophysical processes, but most work to date has largely ignored the role of biology.
Sediments harbor a diverse and abundant biological community whose feeding, burrowing, and construction activities contribute to variability in the bulk properties of sediment. Further, the species themselves can form discrete sources of acoustic scatter that differ to the signal that is received from surrounding consolidated sediment. A logical next step is to incorporate how biological communities modify the physics of seafloor sediment in models of seafloor processes. Although numerous examples of biological and geophysical modification of the seafloor exist, their utility is often constrained to a particular context and/or species, and the wide range of possible biological and physical interactions are not generally considered because of the assumed necessity to establish information from all possible species environment permutations. Hence, little or no information is available for most invertebrate groups and basic data on how species modify the acoustic properties of sediment are yet to be assembled or considered.
Here, we will establish baseline information on how organisms that live in the sediment affect the acoustic properties of the seafloor and use these to improve existing models that are used to characterise the seafloor.
Type of project: Office of Naval Research
Principal Investigator: Martin Solan
Funding provider: Office of Naval Research
Funding dates: 01 August 2018 to 31 July 2022