Quang Ninh warns of fire jellyfish appearing across multiple coastal areas.

Identifying box jellyfish / sea nettles in Quang Ninh waters

Jellyfish species characteristics and areas where they have been recorded

According to the Quang Ninh Department of Agriculture and Environment, the jellyfish species recorded has the scientific name Chrysaora sp., commonly known as stinging jellyfish or sea nettle, belonging to the family Pelagiidae. Scientists from the Institute of Oceanography Branch in Hai Phong and the Institute of Oceanography studied the provided photos and videos and initially identified this jellyfish species. Chrysaora sp. has an umbrella diameter of about 15-20 cm, is semi-transparent or pale yellow, and its surface often features star-shaped brown markings. Notably, the tentacles of this jellyfish species can be 2-3 times longer than the umbrella's diameter, containing cells that cause severe irritation upon contact with human skin. A person who comes into contact with the tentacles may experience a sharp, burning, or stinging sensation; the affected skin area may develop a red rash, swelling, elongated welts along the contact lines of the tentacles, and in some cases, blistering and water blisters. According to scientists, Chrysaora sp. jellyfish is not a newly emerged species in Vietnam. It is typically distributed in coastal waters with relatively high salinity and clarity.

In Quang Ninh, scientists have recorded stinging jellyfish appearing at relatively high densities in the Tra Co sea area. Typically, jellyfish can appear in large numbers from June to August; however, the timing and distribution density may vary depending on seawater temperature and salinity conditions. The Quang Ninh Department of Agriculture and Environment has requested local authorities and beach management units to strengthen information dissemination and warnings, advising residents and tourists to limit or avoid swimming in areas where high densities of jellyfish have been recorded. Beaches are required to study and deploy barrier nets and arrange appropriate personnel and equipment for scooping up jellyfish to minimize the risk of jellyfish and tentacles drifting into swimming zones.

Proactively monitoring and identifying potentially irritating marine species not only contributes to protecting public health but also helps coastal localities better manage ecosystems, ensuring safety for tourism and the sustainable exploitation of marine resources.