Lifeguards have closed some waters off Maui after hearing reports a shark bit a female snorkeler. The state Department of Land and Natural Resources said lifeguards posted shark warning signs in Kihei Friday. Officials received reports a shark bit the woman 40 feet from shore. The part-time Maui resident was taken to the hospital with lower left leg injuries. Earlier this month, the department warned beachgoers to use extra caution through the end of year. The department noted October accounts for the greatest number of Hawaii shark bites. University of Hawaii researchers say this may be because female tiger sharks migrate south from the Northwestern Hawaiian Islands to give birth. An influx of hungry pupping sharks may boost the likelihood of a bad encounter with a human.