Thinking of swimming under a full moon? You may be more at risk for a shark bite based on the moon phase, according to research at the University of Florida.
Researchers compared 50 years of lunar data with the International Shark Attack File and found a relationship where more shark attacks occurred when the moon was more than 50% full, in contrast to fewer shark attacks than average when lunar illumination was less than 50%.
Recommended Videos
Most attacks occurred with 61–70% of the full moon phase.
A previous study found sharks, about 80 miles south of Jacksonville in Volusia County, did have a link between lunar cycles and shark attacks on humans, but these results are the first global evaluation to report evidence of shark attacks correlated to the moon phase.
The type of sharks had little overall effect on attacks by lunar illumination. Neither bull shark nor tiger shark attacks showed any relationship to moonlight. White sharks had a decrease in attacks during dim illumination within 10% of a new moon.
While the risk of shark bites increases closer to a full moon, scientists don’t know what causes sharks to be more aggressive. One hypothesis is that the relationship with the moon’s magnetic activity with a full moon may impact a shark’s internal electromagnetic stimuli.
This information could be useful toward evaluating attack risk and developing recommendations for water-based recreational activities.