(BIVN) – State and county officials issued a rare “Ocean Safety” message on Thursday afternoon, warning beachgoers of box jellyfish along West Hawaiʻi shores.

The Hawaiʻi Department of Land and Natural Resources reported box jellyfish at Spencer Beach Park in South Kohala and at other Kona-side beaches on Hawaiʻi island.

“Box jellyfish are small and nearly colorless making them difficult to see,” a Hawaiʻi County Civil Defense message stated. “Seven to ten days following a full moon, which last occurred January 17th, box jellyfish come close to shore that can pose a possible hazard.”

Officials say box jellyfish venom is poisonous. “In extreme cases, the venom can cause paralysis, cardiac arrest, and even death,” the civil defense message stated.

Beach-goers, swimmers, and surfers were advised to:

• Exercise caution and heed all instructions given by ocean safety officials and beach park staff.
• Avoid entering the water where box jellyfish are present.
• Keep vinegar in your first aid kit and available.

Although such warnings are commonly posted for Oʻahu beaches, they have rarely been issued for Hawaiʻi island beaches.