Does water temperature or salinity impact the signal?
Temperature and salinity change the density of water, which may speed up or alter the acoustic return. In many cases, changes from temperature and salinity are extremely subtle and undetectable. However, dramatic changes may be detected if a distinct thermocline or halocline (boundary between water due to temperature or salinity) exists in the water column. A thermocline or halocline may act as a barrier to sound waves and/or distort the return value. Do gas bubbles impact the signal? Small gas bubbles resulting from wind or currents mixing the surface water or released from plants can impact the return of the sound wave. Gas bubbles are strongly reflective to sound waves, especially at higher frequencies. They can produce a return that interferes with detecting the bottom or distorts the actual bottom return, hindering determination of habitat. In addition to forming near-surface turbulence, gas bubbles can occur when actively photosynthesizing submerged aquatic vegetation releases ox
