# Jellyfish bloom in Istria, Croatia > Live situation record from CLSTR: https://clstr.news/situations/jellyfish-bloom-in-istria-croatia > Updated: 2026-08-25T07:32:00.000Z. Sources: 12. Developments: 2. Large concentrations of jellyfish, specifically the species Cotylorhiza tuberculata, have appeared in the waters surrounding the Istrian peninsula in Croatia. Significant numbers have been recorded near Pula, Rovinj, and Poreč, with densities reaching approximately two adult individuals per square meter in certain areas. Commonly referred to as ‘fried egg’ or ‘sunny-side up’ jellyfish due to their yellowish appearance, these creatures derive their color from a symbiotic relationship with algae living within their tissues. Experts from the University of Pula and the Pula Aquarium attribute their presence near the shore to wind and sea currents. Specialists emphasize that the species is native to the Mediterranean and poses little danger to humans, as their stinging cells are generally too weak to penetrate skin, typically causing only a mild tingling sensation. Authorities and experts advise the public not to touch or remove the animals from the water, noting their ecological importance as they provide shelter for young fish. ## Timeline ### 2026-08-25: Istria coast experiences large jellyfish bloom Large numbers of Cotylorhiza tuberculata jellyfish, nicknamed ‘sunny-side up eggs’, have appeared off the coast of Istria, Croatia, though experts say they pose minimal risk to swimmers. 8 sources. https://clstr.news/cluster/istria-coast-experiences-large-jellyfish-bloom ### 2026-08-23: Istria jellyfish surge causes concern for tourists A surge of “fried egg” jellyfish near Istria's coast has concerned tourists, but experts confirm the native species is harmless to humans and plays a key role in the local marine ecosystem. 6 sources. https://clstr.news/cluster/istria-jellyfish-surge-causes-concern-for-tourists --- Cite as: Jellyfish bloom in Istria, Croatia. CLSTR, https://clstr.news/situations/jellyfish-bloom-in-istria-croatia