Well, yes, Rotenone is used in the farm-fishing industry to ‘weed out’ the undesirables, but the average home gardener doesn’t have water on their land and isn’t using Rotenone anywhere near water. Runoff isn’t a problem, but might be if someone is using it in massive quantities on an entire field of cabbages next to a creek, I’d imagine. Highly unlikely, as a large-scale farmer would use something MUCH more toxic. Ugh.
The stuff becomes inert after a short time (as does Round-up) so runoff for the average consumer that sprinkles a cup or so on a row of cabbages isn’t a grave concern. The Eco-Nuts I work with swear by the stuff, and they’re paranoid about EVERYTHING from aluminum in under-arm deodorant (therefor they don’t use it) to being convinced that drinking out of a plastic water bottle is going to kill them instantly. *Rolleyes*
Why would you have runoff from your garden going toward your fish pond in the first place? Was it the only place to site your pond or garden? If so, don’t use any insecticides and just plant more crops because the bugs are going to take a percentage of them until you have your eco-system up to snuff...and having a pond with lots of frogs around to eat bugs is a good thing. :)
The pond covers approximately 3.5 acres and was created 35 years ago by damming up the area that was the natural drain for our homesite, as well as another 100 acres or so just north of the house. If there is a good rain, not uncommon here in Louisiana, it is very likely that water from just about anywhere on the homesite will end up in the pond. As the pond provides recreation as well as a great deal of food for us, we are hyper-aware of what may enter the water.
The garden is where it is for several reasons: (1) it is one of the only parts of the yard that is not shaded by huge trees, many much older than you and I; (2) it is the best soil on the homesite, we believe because for decades it was the site of the cow yard and barn; and (3) with 150 feet of hose I have access to the water faucet at the garden shed.
As always, you have provided me with information that I did not have ... which is that after a time Rotenone becomes inert. Thank you. I will do some further reading on this product to determine if it will be useful to my yard and garden area in limited amounts.
The eco-nuts you work with would love the stories of my late FIL who, back during the early part of the 20th century, applied DDT or some such poison to cotton barehanded from a croaker sack with no mask, while riding a mule. They might be interested to know that he lived to be 98.5 years old ... 97 of those years in excellent health. ;-)
Frogs??? Do not even go there please! We have so many of those creatures that the nightime hours are deafening with their songs. And they don't do nearly enough bug eating, being as how Louisiana has to be the bug capitol of the entire world. Well, maybe some hellhole in Africa or Asia has more, but I seriously doubt that.