Three-dimensional visualization of a widow rockfish (Sebastes entomelas) shoal over interpolated bathymetry

Acoustic data from repeated acoustic surveys of a shoal of widow rockfish (Sebastes entomelas) were portrayed as three-dimensional images over an interpolated bathy-metric surface. Through development of a number of sub-programs which defined the relationships between different elements of the data, the large data sets could be quickly processed and visualized to gain an understanding of fish distribution, density, and behaviour. The images facilitated discussion of the survey results with commercial fishers and added credibility to the biomass estimates. The images allowed fishers to verify that the density and size of the shoal during the surveys was typical of what they had seen on their sounders and had wanted assessed. The images also confirmed that the shoal's spatial extent had been fully surveyed. Furthermore, the images were effective for examining the diel behaviour of the shoal and communicating to the scientific community the habitat affinity of this species to high relief bottom topography.