When you say
they are going to "shock it to bring the fish to the surface."
that is exactly what they are going to do. They will use a specially made device that will put current into the water, that will sorta temporarily paralize the fish and they will come to the surface.
Rotenone would not make them float, only have them attempt to escape it and then suffocate. Some fish will run themselves into the pond bottom during this process and you would never see them. They will probably use rotenone after everyone has grabbed what they want from the shocking using their nets. Its pretty neat that they are going through the trouble to shock it to allow everyone this opportunity. I'd suggest getting a NET!!
