harleypiker wrote:
I read a scientific paper on how barometric pressure can be measured in the air because it is compressible. But water molecules cannot be pressured tighter together. Therefore they do not have instruments that can measure pressure changes in water. They were at a loss over what fish can be sensing. But I have, too, observed changes in fish behavior so it remains somewhat of a mystery.
Actually they measure pressures in all liquids differently. Instead of inches of mercury used in barometric pressure they measure pounds per square inch (psi) for liquids. The pressures in water are far greater than we experience in our atmosphere. Pressures in water increase .445psi for each foot of depth.