A comprehensive review of tiger shark bite records from 1995–2024 confirms a consistent October surge—“Sharktober”—with the month responsible for up to 20% of recorded bites. The spike appears driven mainly by tiger shark reproductive timing and partial migration of mature females to nearshore waters, which may increase foraging activity. Researchers recommend further study (including non-invasive ultrasound) and urge informed caution in October while noting overall risk remains low.
Confirmed: ‘Sharktober’ — Tiger Shark Bites in Hawaii Spike Every October
Scientists confirm ‘sharktober’ is real as decades of data reveal month when attacks spike
A new analysis of decades of records confirms that tiger shark bite incidents in Hawaiian waters rise sharply each October — a pattern colloquially known as “Sharktober.” The study, which examined bite data from 1995 through 2024, found that October can account for as much as one-fifth of all recorded shark bites in Hawaii.
What the Study Shows
Researchers report the October increase is statistically significant but emphasize that the overall risk to beachgoers remains low. The rise in incidents is primarily linked to tiger shark biology and seasonal movements rather than increased human water activity.
Biological Drivers
The team found that tiger sharks are more frequently present in nearshore waters around the main Hawaiian Islands during September and October. The timing coincides with the species’ pupping season: tiger sharks give birth to large litters in September and October, and many mature females move partially from the Northwestern Hawaiian Islands to the main islands around this period.
Female tiger shark (Cory Fults)
Because birthing and lactation are energetically costly, postpartum and late-term pregnant females may increase foraging activity to replenish energy reserves. The researchers suggest that this heightened foraging could increase the likelihood of human–shark encounters and therefore the number of bite incidents in October.
“The October spike is real and statistically significant, but the overall risk remains very low,” said Carl G. Meyer, a co-author of the study published in Frontiers in Marine Science.
“This pattern appears to be driven by tiger shark biology, not by more people being in the water,” added Meyer, a marine biologist at the University of Hawaii at Manoa.
Recommendations and Next Steps
The authors call for further research to identify the main drivers behind the seasonal spike and to refine risk-mitigation strategies. They propose non-invasive ultrasound monitoring of nearshore tiger sharks to determine pregnancy status and better test whether reproductive condition is linked to increased bite risk.
Researchers hope the findings will help visitors and local communities make informed choices about beach and ocean use during October. They recommend heightened awareness and precautionary measures during the month — not alarm — so people can enjoy coastal recreation while coexisting safely with sharks.
Key study details: Data range 1995–2024; tiger sharks account for at least two-thirds of attacks in October; October can represent up to ~20% of annual recorded bites in Hawaii.
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