The situation along waterways flowing into the Oder River has improved following the discovery of tons of dead fish earlier this year, the Polish authorities said in Warsaw on Wednesday. A ban on the use of a section of the Gliwice Canal, the Dzierżno Duże reservoir and the Kłodnica River had been lifted, the head of the Silesian administrative region told the Polish Press Agency (PAP). Tests had shown a decline in toxic golden algae and in the number of dead fish in the waterways, he said. Since the beginning of August, the authorities have removed some 128 tons of dead fish, imposing a ban o…