A highly venomous jellyfish, native to the Pacific Ocean, has been discovered in the Øresund strait and is currently housed at the Øresund Aquarium. The clinging jellyfish, as it is known, poses a threat due to its potent venom.

Aquarium manager Jens Peder Jeppesen suggests the jellyfish likely arrived in Danish waters via the ballast water of ships. The discovery was accidental, occurring while aquarium staff were collecting local jellyfish species for display. The small size of the clinging jellyfish, reportedly about the size of a thumbnail, allows it to easily conceal itself within the aquarium environment.

Jeppesen warns the public to exercise caution and avoid contact with the jellyfish, emphasizing its dangerous venom. The clinging jellyfish has also been sighted along the Norwegian coast, with recent observations reported near Arendal and previous sightings in the Stavanger area.

The Norwegian Institute of Marine Research has classified the clinging jellyfish as an invasive species. Its venom can cause severe pain, swelling, and respiratory distress in humans.