There's no reason to rotenone - not remotely. Not a great suggestion. All he needs to do is harvest some of the bass, which is easily accomplished with a pond of that size (especially smaller bass, which have roughly the IQ of dirt) and stock forage, which is also easily accomplished. He probably already has a few bass that have managed to reach larger sizes, probably has a couple in there that are five or six pounds or better; beyond that, the bass will start to grow faster as soon as their numbers are thinned, and the bluegill will increase in numbers significantly within far less than a year. The bluegill that are already in the pond will have the best spawn they've had in years next spring if he harvests some bass between now and then, and he'll be much further along toward having a strong forage base than he would be starting from scratch.
If he harvests some bass this fall and stocks TS and GSH, he'll have a good number of two-pound and better bass by this time next year, which he wouldn't remotely have if he started over.
Rotenone not only kills fish, but it kills other aquatic organisms all the way down the food chain. I read a study recently in which biologists found that it can sometimes take years for everything from crayfish to invertebrate larvae to rebound in a BOW that's been rotenoned.
