Dead fish float in Beaver Creek on Tuesday after state workers two weeks ago moved the fish from the West Bank spillway basin into the creek. Brian Miller, assistant manager at Grand Lake St. Marys State Park, said Tuesday the lake is at normal pool, meaning no water is flowing over the spillway into the creek. When the flow stops, dissolved oxygen levels drop, the water temperature increases and the fish suffocate and die in the spillway basin. Some also die once they get into the creek and exhaust themselves trying to swim upstream, a spawning instinct. Miller said state officials plan to open the tubes at the base of the spillway to flush the dead fish downstream. State workers have had to deal with fish getting trapped in the spillway almost every year since the new spillway opened in 1997. Any spillway modifications that might lessen or stop the fish kills have been deemed too costly, Miller said.