Why Dead Fish at Lost Creek?

[Trent_S]

I took my toon out on Lost Creek today. After launching I noticed many dead fish all along the bottom in about 10 feet of water. There were at least 100 that I could see. I am pretty sure they were trout and all the same size (about 12" long). The water temp was 67F today. The visibility was about 10'. I am guessing these were planters that had some sort of acclimation problem (perhaps with oxygen)? On my sonar I saw other masses of fish along the bottom in that area that might also have been dead (they were more like bumps on the bottom than arcs). These fish were already grey colored and starting to rot. They probably did not die today but several days ago.

Are there any experts on this site that know what the cause is for this? 

Thx.