Why did Russia lose less population than other nations during plagues ?
Natural explanations have been suggested for most of the phenomena : Plague 1 — water turned into blood ; fish died * Dr. Stephen Pflugmacher , a biologist at the Leibniz Institute for Water Ecology and Inland Fisheries in Berlin believes that rising temperatures could have turned the Nile into a slow - moving , muddy watercourse - conditions favorable for the spread of toxic fresh water algae .