The minimum DO for many of the sport fish is around or close to 3ppm (mg/L). The graph nicely shows that when the DO dropped into the 3ppm zone and lower, the bass did not survive. Some of the bass and other fish could have survived until the DO was in the 2+ppm range.
For those interested, keep in mind that the DO loss normally begins at the bottom and 'works its way' toward the surface. I assume the measurements for the data in the graph above were made fairly close to the surface. Depending on features on top and under the ice DO in all the water may not decrease evenly throughout the pond. There may be small zones or pockets where DO is lower or slightly higher.
Last edited by Bill Cody; 01/31/11 08:00 PM.
