In the reservoirs of the American state of Illinois, mass mortality of fish was recorded, both in natural reservoirs and in private ponds.
People began to mass appeal to the state environmental protection agencies with demands to explain what is happening. The answer was standard, according to the authorities, the cause of the mass death of fish was the flowering of poisonous algae. However, with such an explanation, the owners of private ponds and reservoirs do not agree that there are no algae in their ponds.