Hey, Bill. I don't think you lost a bet. The truth, as usual, is likely somewhere in the middle.

After I wrote my reply yesterday, I did a quick search to see if I could find any papers on the effects of rotenone on eggs.

I didn't find much, and the only one I found was for trout and salmon.

For brook trout and chinook salmon, it took more than 3 ppm to kill 50% of the eggs after 96 hours in the treatment. However, lake trout were quite sensitive, and once rotenone got over 1 ppm, half the eggs would die in 96 hours.

The amount to kill the small fingerlings was VERY low. After 96 hours, half of the chinook salmon, brook trout, and lake trout would be dead at rotenone levels of 0.05 (salmon and brookie) and 0.03 (lake trout) ppm.

So, we can probably conclude that enough rotenone will kill at least some fish eggs, and that eggs seem to be a lot harder to kill than newly hatched fish. However, I didn't find any information on any of the warmwater fishes. Regardless, it's probably best not to count on the rotenone to kill fish eggs.

Once again, if any of the pond management experts have any furhter information, we'd sure like to hear from you.

Dave

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From Bob Lusk: Dr. Dave Willis passed away January 13, 2014. He continues to be a key part of our Pond Boss family...and always will be.