Authorities have closed several beaches along Florida's Gulf Coast after a woman and two teenage girls were injured in two separate shark attacks on Friday. Beaches have since been reopened with warning flags posted to alert swimmers of the high hazards.

The attacks occurred off beaches in the Florida Panhandle, specifically in Walton County. In response, the sheriff's office, fire department, and state wildlife agency have joined forces to patrol the water with boats and the shore with vehicles, ensuring the safety of beachgoers.

"These incidents are very rare," stated Demian Chapman, a scientist and director of the Center for Shark Research at the Mote Marine Laboratory and Aquarium in Sarasota, Florida. He emphasized the rarity of having two separate attacks on the same day involving three individuals, calling them "astronomically low odds."

The first attack took place on Friday afternoon near WaterSound Beach, where a woman suffered critical injuries on her midsection and arm. In efforts to save her life, part of her arm had to be amputated, and she was airlifted to a trauma center.

Less than two hours later, a second attack occurred about 4 miles east of the previous incident. Two teenage girls, who were in waist-deep water with friends, were both injured but to a lesser extent. One girl sustained significant injuries on her upper leg and hand, while the other suffered minor injuries on her foot. They were both immediately attended to and one of them was also airlifted to a trauma center.

Although it is uncertain whether a single shark or multiple sharks were responsible for the attacks, authorities have noted an increase in shark population in the Gulf of Mexico. Overfishing in past years had caused a depletion in shark numbers, but now there appears to be a recovery. The presence of small fish in schools near the shore during this time of year may have contributed to the incidents.

The timing of the attacks, which occurred in the middle of the afternoon, was also considered unusual. Typically, officials warn individuals to be cautious during the early morning and at dusk, the feeding times for sharks.

In a separate incident, a woman in Hawaii was seriously injured in a shark attack off the island of Oahu. Shark attacks remain uncommon, with only 69 unprovoked bites reported worldwide last year, ten of which were fatal.

Authorities remind beachgoers to exercise caution while swimming and to remain vigilant of their surroundings, as sharks are always present in the Gulf.