According to the text, a theory has emerged that suggests volcanic eruptions on an Aegean island caused acidic rain to fall around 3500 years ago, affecting the Nile's ecosystem. The rise in the Nile's water levels, up to five to ten times its normal amount, also carries red sediments that give the river its nickname "Red Nile." The locals considered this a bad omen, as the river would turn foul-smelling and change color. The red color of the Nile is said to be caused by sediment from the mountains of Ethiopia during heavy rainfall, which is also the setting for the well-known story of Moses parting the Red Sea. Additionally, water quality, sedimentation, and natural phenomena are being studied by researchers to understand the reasons behind the Daldykan river turning a blood-red color. In late July, the Nile's water levels rose even more quickly, bringing along more red sediment from the Ethiopian highlands.