Reasons to Believe

Exodus: Turning Water into Blood

In August of this year, reports surfaced of a crisis in Toledo, Ohio, that “sent more than 500,000 metro Toledo residents scrambling for bottled water.”1 The municipal water had become undrinkable and even unusable for bathing due to contamination by harmful blue-green algae. The algae occur naturally in Lake Erie, the source of Toledo’s water, but this summer the quantity of algae was much greater than usual. Heavier spring rainfall had fed the algae with large quantities of chemical fertilizers due to above-normal runoff from farms along the lake; and an invasion of foreign zebra mussels had removed competitors to the algae. To make matters worse, winds concentrated the algae at the west end of Lake Erie near Toledo.

Now, let’s rewind several thousand years, to the epic story of the Hebrew nation’s exodus from Egypt. Pharaoh’s first refusal to free the Israelite slaves initiated a series of terrifying plagues that started with the mighty Nile River turning into blood. 

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. And the fish that [were] in the Nile died, and the Nile became foul, so that the Egyptians could not drink water from the Nile (Exodus 7:20–21, NASB).

It is, of course, possible that God performed a supernatural miracle and literally turned the water of the Nile into blood—but does the biblical text support this conclusion? We believe that what happened in the Nile is better explained as a hypernatural miracle, which may have involved toxic red algae in a manner similar to Toledo’s trouble with blue-green algae.

Literal Blood?

Significant biblical problems challenge the interpretation that God turned the Nile into actual blood. For example, Exodus 7:22 tells us that the Egyptian magicians were able to repeat the miracle. It seems unlikely the magicians would be able to turn water into literal blood. Also, the Bible does not mention that God himself reversed the miracle, which would have been necessary if it were really blood.

Moreover, a similar event is described in the Ipuwer Papyrus, an ancient Egyptian document from the early second millennium.2 This account implies that the Egyptians had seen red water before, though never at the magnitude Exodus describes. The Bible’s portrayal of the Egyptian reaction to the Nile’s contamination suggests the same thing. For example, the Hebrew in Exodus 7:18b—“the Egyptians will find difficulty in drinking water from the Nile” (NASB)—can be literally translated as the Egyptians were “tired out” [la’ah], perhaps by digging for water (Exodus 7:24). If the river were really blood, their attitude would probably have been alarm and horror rather than exhaustion and frustration.

And like the people of Toledo, who knew what to do and fixed their problem in a few days, the Egyptians knew what to do to obtain potable water. Exodus 7:24 says they filtered water by digging into the riverbanks. If the river were literally blood, it could not have been filtered in this way.

Red Algae and Other Explanations

It seems more likely that what God did to the Nile was a hypernatural miracle. In a hypernatural miracle, God exercises extraordinary control over nature for a particular purpose. He uses natural law and natural phenomena in an extraordinary way to bring about His will (see Psalm 104:4; 148:8), rather than acting supernaturally and violating the laws of physics.3 Hypernatural miracles encompass extraordinary timing, an extraordinary selection of location, extraordinary magnitude, and/or extraordinary selectivity. We suggest that hypernaturalism explains many of God’s miracles as a combination of divine power and natural law, thereby demonstrating God’s total authority over creation.

Several scientific explanations have been offered to account for the Nile’s vivid red color, the death of fish, and the fouling of the river. In 1957, scholar Greta Hort suggested it was due to silt from the river’s southern tributaries which carried flagellate protozoa.4 But in the 1990s, analysis by H. M. Duncan Hoyte5 and John S. Marr and Curtis D. Malloy6 suggested the miracle was due to an infestation of toxic red algae. Writing from an epidemiological point of view, Marr and Malloy offer evidence for their hypothesis:

Recent explanations for the red-colored waters have favored protozoan, zooplankton, dinoflagellates, and both salt- and fresh­water algal (phytoplankton) blooms. All of those blooms—plant, fungal, or protozoan—deoxygenate water and produce noxious toxins for both fish and frogs….We conclude that a freshwater dinoflagellate biomass bloom…was responsible for the change in the color of the Nile [and] the death of fish.7

The one missing ingredient in this analysis is identification of the toxic red algae involved and confirmation that it was present in the Nile at the time of the Exodus. Unfortunately, this is impossible because the construction of the Aswan High Dam—which prevents the annual flooding of the Nile as described in the Bible—has significantly modified the river’s ecology.

Nevertheless, this epidemiological argument is plausible. And if the blood-like appearance of the Nile during the confrontation between Moses and Pharaoh was indeed due to red algae, the event has all the characteristics of a hypernatural miracle:

  1. It was a natural event that apparently occurred from time to time on the Nile; the only difference was the intensity of the algae invasion.
  2. The algae invasion occurred when Moses struck the water with his staff; that is, at a precise time and place to affect God’s purpose.

How did God cause this hypernatural miracle to happen? We don’t know. But the Toledo example of winds and heavy rains suggests two forces of nature God could have used to stunning effect in turning the Nile as red as blood.

Daniel J. Dyke, MDiv, MTh

Mr. Daniel J. Dyke received his Master of Theology from Princeton Theological Seminary 1981 and currently serves as professor of Old Testament at Cincinnati Christian University in Cincinnati, OH.

Dr. Hugh Henry, PhD

Dr. Hugh Henry received his PhD in Physics from the University of Virginia in 1971, retired after 26 years at Varian Medical Systems, and currently serves as Lecturer in physics at Northern Kentucky University in Highland Heights, KY.

Subjects: Bible Difficulties

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  1. Tom Henry, “Water Crisis Grips Hundreds of Thousands in Toledo Area, State of Emergency Declared,” The Blade, published August 3, 2014,
  2. A. H. Gardner, Admonitions of an Egyptian Sage (Leipzig, Germany: J. C. Heinrichs, 1909).
  3. This is not meant to imply that God never acts supernaturally. The virgin birth and Christ’s resurrection would be examples of important supernatural miracles.
  4. Greta Hort, “The Plagues of Egypt,” Zeitschrift fur die Altestestamentliche Wissenschaft 69 (1957): 84–103.
  5. H. M. Duncan Hoyte, “The Plagues of Egypt: What Killed the Animals and the First Born?,” Medical Journal of Australia 158 (1993): 706–8.
  6. John S. Marr and Curtis D. Malloy, “An Epidemiological Analysis of the Ten Plagues of Egypt,” Caduceus 12, no. 1 (1996): 10.
  7. Ibid.