The Iowa Department of Natural Resources has decided not to drain a popular central Iowa lake.Florida had its problems with dangling chad, but in Big Creek Lake in Polk County, it’s the swimming shad that’re making trouble. D-N-R fisheries biologist Martin Conrad says shad rapidly reproduce and gobbled up all the food needed to sustain game fish in a lake. The D-N-R had planned to drain Big Creek to kill off the shad, but Conrad says that residents indicated at a public hearing Tuesday night they didn’t want such drastic action. Conrad says the D-N-R will try something else to kill the shad. He says they’ll stock predator fish that attack the shad. Martin says Big Creek is too big to use chemicals to kill off the shad. Conrad says Big Creek is an example of the big task of managing the fish population in the state’s lakes. He says its similar to a farmer trying to grow the best crop by knocking out weeds, and in this case, the shad are the weeds.Martin says they’ve successfully gotten rid of shad in two other central Iowa lakes near Indianola and Oskaloosa and cleaned out carp in other lakes. He says killing unwanted fish takes a lake out of service for awhile, but says the benefits are better in the long run. He says studies show recreational visits of all kinds increase after the fishing has improved in a lake.Martin says they’ll continue to monitor Big Creek Lake to see if the game fish are surviving.