Two years after rampant algae growth killed tons of fish and other wildlife in the Oder river, Poland is again battling to prevent toxic golden algae spreading into the giant waterway. An ammonium compound has also been used for several days in the Gliwice Canal branching off from the Oder, the Ministry of Climate and Environment told dpa in Warsaw on Friday. “Scientific studies have shown the effectiveness of ammonium nitrogen in reducing golden algae,” a spokesperson said. The dosing is being carried out in strictly defined quantities under the supervision of scientists from the Institute fo…