This is my comment from the other "twin" thread about this pond.
"It does look like a good pond for amphibians. I suspect that it has frequent fish kills especially during winter due to dissolved oxygen loss. The main thing you should do when the ice melts is to determine how deep it is and how thick the muck layer is on the bottom which is likely 3ft+ thick."
Now for some additional input. Michigan State Univ suggests that better success with sport fish ponds in MI will be with ponds 15t deep or more and 18-20ft is distinctly better. Depth of 10-12 ft they say are for fishery ponds in more southerly states.
From one of their online publications:
""For fish ponds in Michigan
you want the depth to be at least 12-15 feet throughout as much of the pond as possible, but at least a quarter of the pond bed. This helps avoid winter and summer oxygen depletion and resultant stress on fish, which can end in poor growth or mass die-off. Having parts of the pond as deep as 25 feet would be even better if possible. Deeper than 25 feet has shown no results as to providing benefits to fish populations.
If maintaining fish populations is not your goal then depth is not as much a factor. Wildlife ponds can be shallow relative to fish ponds.""
Managing Michigan Ponds
http://archive.lib.msu.edu/DMC/Ag.%20Ext.%202007-Chelsie/PDF/e1554-1994-print3.pdfWisconsin Pond Info.
https://woodlandinfo.org/sites/woodlandinfo.org/files/pdf/UWEX/G3693.pdf 
