Pond Boss Forums AERATION Systems questions Winter survival DO vs Hydrogen Sulfide, etc

I'd like to propose a theory/question and get some thoughts.

What is more critical for winter survival of fish, adequate DO levels or removing Hydrogen Sulfide and other poisonous gases?

In winters 2017-18 and 2018-19 we recorded DO levels of ~.8 PPM (using a YSI PRO ODO DO meter) and yet I had trout survive. The readings have been very similar both winters with .8 PPM of DO and water temps in the mid 33 degree area. In both winters I struggled to keep a hole open in the ice for long stretches but had aeration pumps running. The same scenario is playing out this winter. I am now very certain that the air is escaping the lake somewhere I just cannot figure out where. I am assuming the air is reaching the shore somewhere, maybe in multiple places, and escaping, but leaving no visible hole because of the deep snow. With no hole open there is no oxygen transfer to the water hence the low DO levels BUT with the air escaping am I still removing toxic gases from the water and this is allowing the trout to survive???

The trout either manage to find a pocket of water with somehow acceptable DO levels OR the extremely low water temps allow them to survive the low DO conditions. I am wondering if they are surviving low DO AND toxic gases or if I am at least removing the poisonous gas.

This will be my 7th year really working the lake up there and I am always still scratching my dang head. #notverysmart