Example image of echogram from EK60 fisheries sonar. The red feature is the seafloor. Green and blue areas in the water column are features with high backscatter – the lines near the surface show dense layers of biology (zooplankton, fish, gelatinous creatures, etc.), while the vertical lines are bubble plumes emanating from the seafloor. Image courtesy of the NOAA Office of Ocean Exploration and Research, Discovering the Deep: Exploring Remote Pacific MPAs.