City officials will decide this morning whether to re-open Hanauma Bay after a box jellyfish invasion kept the beach closed for the past two days.

More than 40 box jellyfish were found in less than an hour yesterday "with countless more spotted floating just offshore," according to the city Emergency Services Department.

"Due to the potential risk to public safety, the city's Parks and Recreation Department along with the Ocean Safety and Lifeguard Services Division made the decision to close the bay effective at 7 a.m.," said Bryan Cheplic, spokesman for the Honolulu Emergency Services Department.

Yesterday, 56 box jellyfish and 10 Portuguese man-o'-war were found along Waikíkí Beach, and one person was treated by lifeguards for a sting.

In less than an hour Saturday, more than 30 people were treated for stings at Hanauma Bay, prompting its closure at 9:30 a.m.

More than 500 box jellyfish also were found on Waikíkí Beach on Saturday, with more than 50 people requiring treatment for stings.