More than 150 people have been stung by jellyfish on Hawaii beaches in a single day.
Officials reported the extraordinary figures on Monday, 16 January. The stinging incidents took place within a span of three miles on beaches near the state capital of Honolulu on the island of Oahu from Waikiki to Ala Moana Beach, according to SFGate.
One of the victims was a teenage boy, 15, who was taken to the emergency room of a local hospital. He was in stable condition on Monday, Hawaii News Now reported.
Officials put up warning signs indicating that box jellyfish were active on beaches facing south.
Compared to other species, box jellyfish are one of the most venomous forms of marine life. They can become up to 10 feet long and some can transmit enough poison to lead to cardiac arrest in a human in a matter of minutes.
Still, deaths caused by jellyfish are very rare. The jellyfish tend to appear to the south of Oahu about 10 days after a full moon has occurred. Before the 16 January mass jellyfish event on the Honolulu beaches, the previous full moon had occurred on 6 January.
Monday was a federal holiday honouring the legacy of civil rights leader Dr Martin Luther King, meaning that there were likely more people on the beaches of Honolulu compared to a regular Monday.
“Box jellyfish, named for their body shape, have tentacles covered in biological booby traps known as nematocysts - tiny darts loaded with poison,” the National Oceanic and Atmospheric Administration’s (NOAA) website states.
Those injected with the poison may “experience paralysis, cardiac arrest, and even death, all within a few minutes of being stung”.
Out of the around 50 species of box jellyfish, which are also known as sea wasps, only a few have poison that’s deadly to humans.
“While box jellyfish are found in warm coastal waters around the world, the lethal varieties are found primarily in the Indo-Pacific region and northern Australia,” the NOAA site adds.
Unlike other species of jellyfish, box jellyfish can swim and do so with a speed of up to four knots.
“Most species of jellyfish float wherever the current takes them, with little control over their direction,” NOAA notes.
Box jellyfish are also able to see, with eyes located in clusters on each side. Some of the eyes are “surprisingly sophisticated”, including having a lens and a cornea, as well as an iris that’s able to contract amid bright light, as well as a retina.
“Their speed and vision” have prompted “some researchers to believe that box jellyfish actively hunt their prey, mainly shrimp and small fish,” NOAA adds.