Non-Invasive Characterization of Small-Scale Patterns of Benthic Biogenic Structure by Ultrasound: Infaunal Dynamics and Sediment Structure, and Effect of Sediment Disturbance.

摘要

Our goal is to examine how temporal changes in marine, soft-sediment infaunal density, distribution and species composition affects sediment surface roughness and below-surface structure. The use of commercial ultrasonic sensors allows us to examine temporal patterns in biogenic structure and roughness on fine spatial scales (mm) without invasive disturbance. In addition, we are examining how physical disturbance of the sediment affects biogenic structure, both above and below the sediment surface, and determining whether disturbed sediments exhibit a 'signature' in terms of patterns of biogenic structure. Our major objectives are twofold: (1) How does biogenic structure at and below the sediment surface change in sediment assemblages under controlled conditions; What is the temporal persistence of relict biogenic structure under undisturbed conditions; and (2) How does biogenic structure respond to different frequencies of physical sediment disturbance under controlled conditions. Does physical sediment disturbance leave a 'signature' in terms of biogenic structure.