I have no experience with fish that have died due to low DO but I have seen fish die and float at my place. When my Tp die due to cold water as the water temps drop, they have a fungus that grows on them or what I think is a fungus. And your pic of the Bg has the same look with the patch that looks like fungus to me. I have also had the same or similar type of fungus on some of the Golden shiners in my sediment pond when we get large rain events. I think in both cases it was brought on due to stress. So, I would look for something that is different from your norm. Pat, may be right when looking at the grass matts. Maybe a weed killer is in the matt and was washed into the pond during a rain event. In my sediment pond the water will turn color with all the clays being washed in and that causes stress, so any large rain event recently? I may not be much help here but I hope things improve for you soon. Dead and floating fish in large numbers can't be good.

Do not judge me by the politicians in my City, State or Federal Government.


Tracy