Pond Boss Forums AERATION Should I aerate? System foze up.

Please explain how a fish and by what physiological means can 'sense' a slightly higher DO concentration of say 1 or 2mg/L that is say 80-100ft away or in the case of 20 acres on the other side of the pond 600-900 ft away. I missed that part in animal physiology class.

I understand the CC after frequent or occassional association could 'learn' or recognize that when the PTO is running the DO is always higher near the characteristic sound and associated current (probably mostly sound); a Pavlov's dog sort of association. But if the DO happens to be just slightly higher in a cove or on one side of the pond compared to say a side that has had rotenone treatment or heavy organic decay and DO is depleating how does a fish know which way to swim toward higher DO? How do they "sense" which way to go to get out of the low DO before they die? Which is what I think happened to the few small YP that died in the example above (SK-love2fish). I think those small YP got caught in a small "pocket" or zone of low DO. Plus the longer the fish is in dangerously low DO they become more and more disoriented as shown by my observations. The more disoriented they become the more irratic their overall behavior becomes including swimming and most often it appears to me then all swimming is in random directions and not directed toward the areas with higher DO.

Instinctively fish when in low DO will move toward the surface where usually slighly higher DO occurs due to experiences of usually slightly higher DO from the air-water-atmosphere interface. But I do not understand how a fish would know or "sense" to swim right, left, straight ahead or at a 55 degree angle toward higher DO on the other side of the pond.