Biblical Plagues Part 2: The River of Blood

blog post photo

In addition to the Exodus narrative, there’s other written evidence that the ancient Egyptians suffered some sort of awful succession of calamities. The Ipuwer Papyrus, an Egyptian manuscript that dates back to at least the beginning of that span, has the nightmarish feel of the first draft of a George Romero screenplay.

“Hearts are violent, pestilence is spread throughout the land, blood is everywhere, death is not lacking, and the mummy cloth speaks even before one comes near it. Indeed, many dead are buried in the river, the stream is a sepulcher and the place of embalmment has become a stream… the river is blood, and yet men drink of it. Men shrink from human beings and thirst after water.”

It’s impossible not to note the eerie parallel between the blood river described in the papyrus and the plague of blood described in Exodus 7:17–21.

“Thus says the Lord, ‘By this you shall know that I am the LORD: behold, I will strike the water that is in the Nile with the staff that is in my hand, and it will be turned to blood. The fish that are in the Nile will die, and the Nile will become foul, and the Egyptians will find difficulty in drinking water from the Nile.’

“Then the LORD said to Moses, ‘Say to Aaron, “Take your staff and stretch out your hand over the waters of Egypt, over their rivers, over their streams, and over their pools, and over all their reservoirs of water, that they may become blood; and there will be blood throughout all the land of Egypt, both in vessels of wood and in vessels of stone.”‘

“So Moses and Aaron did even as the LORD had commanded. And he lifted up the staff and struck the water that was in the Nile, in the sight of Pharaoh and in the sight of his servants, and all the water that was in the Nile was turned to blood.

“The fish that were in the Nile died, and the Nile became foul, so that the Egyptians could not drink water from the Nile. And the blood was through all the land of Egypt.”

The river of blood is also mentioned in Psalms 78:44 and 105:29.

Video: “The River of Blood”

Pioneering late-19th to early 20th Egyptologist Flinders Petrie — whose discoveries included the Merneptah Stele, the lone document mentioning Israel — theorized that the bloodlike waters were caused by stagnation when water levels were at their lowest. Others have argued that the redness was caused by particles of sediment carried along when the Nile flooded.

In the 1950s, Danish scholar Greta Hort, who consulted extensively with scientists, suggested another possibility — that the river of blood actually was a massive “red tide” of algae, permeated with anthrax bacteria, that spread when the Nile flooded its banks. In his book, Anthrax: A History, Richard M. Swiderski explains how Hort believed that the algae-anthrax flood in turn caused the other plagues:

“According to Hort’s scenario, the blood-red tied washed ashore fish dying of anthrax, which in turn infected the frogs and forced them ashore, where they carried anthrax to domestic animals. The flies multiplying in the shore plants decaying in the floods then fed upon the dying animals and carried anthrax to live animals and humans, precipitating the boils of the sixth and seventh plagues. The severe weather that caused the unusual flooding also accounts for the hail and the locusts. The plague of darkness and the death of the firstborn are also worked into the sequence.”

As Swiderski goes on to explain, Hort’s theory doesn’t really wash. Anthrax doesn’t infect fish or frogs in nature, and the pattern of transmission that she described fits cholera rather than anthrax.

But since then, scientists have nominated other pathogens as possible explanations for the plague. In 1996, epidemiologists John S. Marr and Curtis D. Malloy developed the theory that the plague was caused by Pfiesteria piscicida, a free-swimming, single celled organism blamed more recently for massive fish kills in North Carolina in the 1980s and 1990s. Blood seeping from the dead fishes conceivably could have turned the Nile red. Beyond that, by eradicating predator fish, the Pfiesteria outbreak might have caused the frog and insect populations to explode out of control, creating additional plagues.

One critic of the Pfiesteria explanation is biblical researcher Brad Sparks:

“It is well known that algae — even the strange Pfiesteria — mainly grow in stagnant bodies of water, not in free-flowing rivers. Red tides occur in slower-moving or becalmed saltwater oceans and estuaries rather than rivers (e.g., not one of the 1,109 worldwide Harmful Algae Events in the UNESCO database occurred in a freshwater river). These environments are very unlike the massive freshwater Nile, the second largest river in the world and clearly not a stagnant pond. It is common knowledge that plants need sunlight for photosynthesis, yet Hort’s theory also requires massive loads of intensely dark silt that would kill her plant algae. It is most problematic that her ‘red’ algae are actually green and her ‘red’ Nile silt is actually brown, thus could not possibly have caused a red Plague of ‘Blood.'”

Don’t miss Biblical Plagues: The First Curses and The Final Torments, this Monday starting at 9P et/pt!


  1. Jonah Thompson
    navajo reservation az
    March 31, 2013, 6:35 pm

    There are deposits of methane ice in the medeterranean sea off the shores of egypt. I believe an underwater volcanic disruption slowed or reversed the nile briefly allowing salt water red algae to travel and bloom upriver. The bible says the water in the pots also turned to “blood”. I wonder what the incubation time for a red algae bloom in hand collected water is. I imagine the egyptians were rushing to collect as much uncontaminated water as the waterways changed before their very eyes from a down river upheaval. Subsequently, eruptions occured causing darkness and spewing methane hydrate over egypt. The burning ice hail destroyed the plants and trees of the egyptians but spared israelite inhabited goshen. I would like to see soil sample investigations on any anamalies between goshen and the rest of egypt. I believe the exodus occured at the end of 12th dynasty. The disasters of the plagues and loss of egyptian army left the country unable to defend itself against the hyksos invaders. Its funny how many hyksos rulers took the name moses. They must have attributed great power to that name. Keep in mind i believe the accepted egyptian chronology is misaligned with biblical exodus events. The recent discovery of a drought bringing the end to the old kingdom marks the arrival of joseph into egypt. His leadership lifted the middle kingdom to the golden age of egyptian dynasties. Josephs instituted laws and building projects are clearly seen in archaeologic record of the early 12th dynasty. Also the arrival of semites settling in goshen during this time is evident. Thanks for the forum to express my opinion.

    ged from a down river upheaval. Remember the canals and resavoirs

  2. […] It was not because of the soil runoff that caused the next pending disaster, but the explosion of bacterial growth in the water and Pharaoh’s unyieldingness toward Israel (Exodus 6), not caused by agricultural […]

  3. Beorh Quarterly
    November 5, 2014, 9:24 am

    And why can’t we just believe that it was actual blood?

  4. Pam M
    February 11, 2016, 9:37 am

    Jonah Thompson of Arizona

    I’m a researcher for a novel about these times and I came to the same conclusions, especially after reading about the new evidence of a multi decade drought at the end of the First Kingdom that triggered a dark Intermediate stage.