Some of the local bait shops (free bait or lure coupons) and maybe even Bass Pro Shop or Cabelas might be willing to contribute prizes for the carp fishing tournament. Prizes for most carp, largest carp, smallest carp, oldest-youngest angler, a female division, etc. If you had to pay to net or electroshock the lake that money could be used for tournament prizes.
aka Pond Doctor & Dr. Perca Read Pond Boss Magazine - America's Journal of Pond Management
