Yeah your right there, that would be my first guess also. All the dye is killing everything off I would expect. Although I have dyed my pond in the past and did not see that type of thing, but never for a long period of time. Maybe he keeps that pond with some dye in it all the time that would explain some of it for sure.
RC
I use Aquashade as a management tool when I want less macrophytes and phytoplankton. I've even seen more oxygen under the ice in the ponds I shade on a regular basis due to less plant growth that dies and decomposes using oxygen.
I think it may slow down the food chain some, but if your fish are pellet fed fish what difference does it make unless you depend on natural recruitment?
