Thousands of dead fish were found in the River Oder that separates Poland and Germany. Experts from both countries have not been able to find out the exact cause. Scientists believe that the water’s high salt levels caused chemical contamination. The golden algae grew in number and released poison. This harmed the fish in the river. Andrzej Kapusta of the Inland Fisheries Institute expressed worry that it could happen again, especially if the original source of the pollution is still unknown. Investigators are checking about 60 out of 300 unregistered outflow pipes in relation to the fish deaths. Workers near Szczecin, Poland, remove many dead carp and catfish from the river. Meanwhile, a pump is desperately trying to add oxygen to the water. The river then flows on to a lagoon and the Baltic Sea. The amount of water may then reduce the toxins. However, many are concerned that a “wave of poison” may continue its deadly route downstream.