A great dorsal fin sliced the middle of the brown creek as the shark swam along prairies of sedge grass and wound slowly past deserted banks, undetected by anyone. The air was warm and ripe with the sulfuric rot of the marsh. The water was rising under the shark, and it was attuning itself to new atmospheres. It passed easily through changing water temperatures, and the rising tide was protecting its salt balance.
Also unseen, in the bright afternoon sky, the moon's orbit was on a course that would put it in the earth's shadow two days later. The coming lunar eclipse of July 14, 1916, held no interest for scientists then, but the phases of the moon were fundamental to the shark. The hidden moon was waxing, three days from full, radiating near maximum gravitational pull, and the great white was growing excited and vibrant in reaction to the moon's surging power. Around the world, ocean tides were rising and the tide was coming up Matawan Creek now, swelling the banks and lifting the shark, bracing it with life-giving seawater.
The shark was moving upriver no faster than a walking man, swaying its body from side to side, smelling the water and processing information with great rapidity. As the fish swam, its huge olfactory lobe was evaluating the smells and sounds in the water for potential prey.
Streaming onward in the creek, the shark began to whip powerfully, picking up speed until it was sending water rolling toward the banks. No one saw the shark moving then, nor would anyone have understood the pull of the hidden moon like a trigger on the jaws of the shark, although a man may have felt something different in his blood as well.
The citizens of Matawan in 1916 would not have laughed at the idea that the full moon exerted a powerful effect on people, plants, and animals. It was well known at the time that “lunacy” gripped the residents of jails and mental hospitals during the full moon. In the old German, French, and Scot folk cultures brought to Matawan, evil preyed on human beings under a full moon. If by 1916 lunar superstitions were the fodder of emerging modern entertainment (Dracula was a popular novel), “moon farming,” following the cycles of the moon when planting or harvesting crops, and other myths continued to flourish. Moonlight is harmful to the health, the not-yet-old wives' tales said; fleece will be lighter if sheared when the moon is waning; pork from pigs killed in a new moon will shrink when cooked; rail fences built in the light of an old moon will sink into the ground; wood cut in the waxing of the moon will be “sappy”; fish will bite more on the night of a full moon.
Scientists were dismayed by the persistence of popular myths. “Scientific men devote a deplorable amount of time felling Antaeus, in the shape of one or another of a host of irrepressible superstitions,” Charles Fitzhugh Talman wrote in 1913 in Scientific American. “Whether the giant happens to be the equinoctial storm, or unlucky thirteen, or the climatically impotent Gulf Stream, or the super-moon, the Hercules has not yet arisen who shall crush him conclusively in mid-air.”
The moon held little mystery for science in the early 1900s. Though study of the heavenly body continued, the work was quantitative—the distance from the earth, the strength of the reflected light, the size of the satellite. Scientists believed they understood the moon, and each experiment served only to further prove already established ideas. During the lunar eclipse of that July 14, thousands of New Yorkers would crowd rooftops and towers to watch with fascination the passage of the earth's shadow across the face of the moon, one of the clearest lunar eclipses seen in years. Yet Professor Harold Jacobi of the Astronomical Department at Columbia University declared “it was of no material interest to scientists because it could not possibly reveal anything that was not already a matter of positive knowledge.”
Later, scientists would find evidence that sharks attack more frequently during very high tides, caused by the gravitational pull of the full moon. A preliminary study by researchers at the International Shark Attack File has found a worldwide correlation between “the phases of the moon, the height of tides and the frequency of shark attacks.” Researchers are studying the phenomenon, according to George Burgess, “from a practical standpoint” to “cut down on the number of attacks by warning people of an increased risk.” While there is yet no conclusive proof the white shark fits the pattern, “a study of white sharks near South Africa shows a peak in attacks at the highest of high tides.”
There are several possible explanations for lunar-related shark attacks. The folklore about lunar effects on animals may be true. “There is no doubt that an animal could be more on edge or more active in looking for food due to the phases of the moon,” Burgess says. Sharks could be reacting to the effect of the moon on other ocean species. The reproduction of coral and many types of fish coincides with the cycles of the moon. High tides also reduce beach space, drawing prey such as seals into the water and sharks nearer shore.
Whatever the reason, as the juvenile great white shark cruised through the murky waters of Matawan Creek under a weakening sun and a waxing moon, the waters of the creek were rising. It was nearly two o'clock on the afternoon of July 12, 1916, and the moon would soon be at its most luminous, the creek tides rising to the highest recorded levels of the month.