Box Jellyfish Invade Hawaii Beach, Stinging 30 People

A beach in Hawaii has been closed after a box jellyfish invasion, which caused 30 people to be stung on Sunday morning. The beach remains closed.

The Honolulu Department of Parks and Recreation (HDPR) said there had been an influx of box jellyfish at the beach in Hanauma Bay Nature Preserve on the island of O'ahu, leading to its closure.

"The beach at the Hanauma Bay Nature Preserve will be closing today, 1/19/20, due to jellyfish," a Tweet from the HDPR on Sunday read. "About 30 stings have been reported this morning. The upper areas, including the parking lot, viewpoint, & education center, will remain open. Will reassess beach tomorrow. Mahalo."

Officials expect the influx of box jellyfish to last for three-to-four days, KHON2 reported. Large influxes of jellyfish such as this are not unusual in Hawaii.

Box jellyfish are known for their powerful venom which can instantly stun or kill prey, such as fish and shrimp, National Geographic reports.

The venom of some box jellyfish species is considered to be among the most powerful in the world. Stings from these species can be extremely painful to humans and sometimes even fatal. However, other box jellyfish species do not pose a serious threat to humans.

The three box jellyfish species which can be found in the waters off the Hawaiian islands have less potent venom than some of their relatives. Nevertheless, stings from these animals can still be painful, according to Hawaii Aloha Travel.

Box jellyfish are present in the waters around Hawaii throughout the year. However, influxes of the animals often appear on O'ahu's south facing beaches about eight to ten days following a full moon, according to Hawaii Aloha Travel. This is because their mating habits are linked to certain tidal and lunar conditions. Windy conditions can also blow large numbers of jellyfish towards the shore.

Like other venomous jellyfish, box jellyfish have tentacles lined with thousands of stinging cells which release tiny barbs that can penetrate the skin.

According to research by scientists at the University of Hawaiʻi at Mānoa, many of the recommended first aid treatments for box jellyfish stings, including rinsing with seawater, actually make things worse. Scraping the tentacles and applying ice also increases the severity of the sting, the team said.

Instead, they found the most effective way of treating stings was rinsing the area with vinegar or plucking tentacles out with tweezers. Applying a heat pad after also decreased venom activity.

"Less than one percent of stinging cells on a tentacle actually fire when you're first stung," Christie Wilcox, one of the authors of a study published in the journal Toxins, said in a statement. "So anything you do that moves the tentacles or adherent stinging cell capsules around has the potential to increase the amount of venom injected into you by many fold.

Lead author Angel Yanagihara added: "Box jellies are incredibly dangerous animals. The more venom they inject, the more likely a victim is to suffer severe, even life threatening symptoms. The increases in venom injection and activity we saw in our study from methods like scraping and applying ice could mean the difference between life and death in a serious box jelly sting."