DIED makes a good point. If you don't have a good data base on the pond wrt sizes , numbers , year classes , RW , water quality and chemistry , etc. you should consider having a pro survey the pond and give you a report on how to do what you want. I would take such a report and post it here for additional feed back.

In addition if the shock boat is part of the survey you can use it to cull fish to make room for the additions.