2024 Volume 80 Issue 18 Article ID: 24-18025
In order to gain a detailed understanding of the distribution of seaweed beds, which have attracted attention as a CO2 sink, we performed measurements using airborne laser bathymetry (ALB), a green laser survey technique, at the Port of Wajima. Although the area of seaweed beds is often used to calculate CO2 uptake, we investigated a method to calculate the volume of the seaweed as an indicator of biomass from point cloud data obtained by ALB. The conventional filter method for ALB data has difficulty discriminating underwater noise from seaweed beds; however, the point cloud reflection intensity of the data acquired by ALB can be used to discriminate between them. Using seaweed bed data and seafloor data determined by reflection intensity, the area, average height, volume, and average coverage of the seaweeds beds within the measurement area could be calculated, thus demonstrating the effectiveness of green laser survey as a method for identifying seaweed beds.
