HONOLULU — More sharks could be on their way to Kauai.
A quarter of the mature female tiger sharks near the remote coral atolls of the Northwestern Hawaiian Islands leave for the Main Hawaiian Islands in the late summer and fall, swimming as far as 1,500 miles, according to new research from the University of Hawaii at Manoa and the University of Florida.
“Both the timing of this migration and tiger shark pupping season coincide with Hawaiian oral traditions suggesting that late summer and fall, when the wiliwili tree blooms, are a period of increased risk of shark bites,” said co-author Carl Meyer of UH’s Hawaii Institute of Marine Biology.
First author Yannis Papastamatiou said tiger sharks are present throughout the islands at all times of the year.
The female sharks migration from the Northwestern Hawaiian Islands dovetails with the tiger shark birth season in September to early November — and with the months of highest shark bite risk.
Though rare, shark bites have historically been most frequent from October to December. Traditional Hawaiian knowledge also warns of danger during the fall months.
However, Meyer and Papastamatiou urged people not to leap to the conclusion that this movement of female sharks is related to recent shark bites around Maui, Oahu and the Big Island.
Many factors might influence shark behavior in ways that would lead to more frequent encounters with people, Papastamatiou said.
Papastamatiou said there is a more likely connection to pupping, with female sharks swimming down to preferred nursery sites in the Main Hawaiian Islands, which may offer different foods, protection from ocean waves, or some other, unknown factor.