Why do we see box jellyfish 8-12 days after a full moon?

Box jellyfish are typically reported 8–12 days after a full moon, and experts attribute the timing to lunar cues that trigger migration for spawning. Joey Donovan, Gelatinous Zooplankton Specialist at the Waikīkī Aquarium, said box jellyfish are pelagic organisms carried by currents and move with prevailing water flow. He explained that they shift toward shore in response to lunar signals to breed, while Portuguese man o war usually appear on windward sides because they have a sail that the wind pushes toward land. A third type can arrive after a Kona low storm causes upwelling of deeper water. Donovan noted that stings occur when specialized cells inject venom, producing burning sensations and red welts. Ocean Safety lifeguards said activity may be greater in the early morning, with jellyfish often concentrated near beach edges and corners, and that heavy influx weekends can mean hundreds or thousands of stings in a month. Lifeguards recommend waiting later in the day, and if stung, seeking evaluation where vinegar and heat may be used.