Scientists Warn of 'Itchy Jellyfish' Outbreak in Quang Ninh Coastal Waters

A significant outbreak of jellyfish known to cause severe itching upon contact, identified as Chrysaora sp., has been confirmed along the coast of Quang Ninh province in northern Vietnam. Scientists from the Institute of Oceanography, under the Vietnam Academy of Science and Technology, responded to a request from the Quang Ninh Department of Agriculture and Rural Development. They analyzed provided images and videos, consulting with Japanese experts, to identify the species and offer information. The identified species is Chrysaora sp., commonly known as the 'itchy jellyfish' or 'fire jellyfish,' belonging to the family Pelagiidae. This jellyfish is relatively small, with a body diameter typically ranging from 15 to 20 cm. The bell is hemispherical or slightly flattened, translucent or pale yellow, often featuring dark brown, star-shaped patterns with about 32 radial lines on its outer surface. Its tentacles are long, frequently two to three times the bell's diameter. According to scientists, this jellyfish species is recorded in many coastal waters of Vietnam. From June to August, after the populations of commercially important jellyfish like white and red jellyfish decline following early rainy seasons, the itchy jellyfish can appear in considerable densities in waters with relatively high salinity and clarity. Previous observations in August 2019 near Trà Cổ beach recorded two species of itchy jellyfish in the surface layer at densities of approximately 30 to 50 individuals per 1,000 square meters. Chrysaora sp. has a strong potential to cause itching upon contact. Individuals touching its tentacles may experience sharp pain, a burning sensation, or a stinging feeling. The affected skin can develop redness, swelling, long streaks corresponding to the tentacles, and even blisters or pustules. Notably, the timing of their appearance and distribution areas often overlap with waters close to beaches where swimming and tourism activities take place. Consequently, this species can significantly impact recreational activities at tourist sites nationwide. The identification and scientific information provided on the biological characteristics, seasonality, and stinging potential of this jellyfish species will help authorities and the public gain a clearer understanding of the jellyfish outbreak in Quang Ninh's coastal areas, particularly in zones frequented by swimmers and tourists. Source: Nhan Dan