When the sun dips below the horizon on August 29, the historic Arsenal building in Hvar will transform into a canvas where the sea and its hidden guardian – Posidonia oceanica – will speak.
– Posidonia will come to life on the Arsenal façade from 8:00 PM to 11:00 PM! We invite locals, visitors, and everyone interested to a free audiovisual event that blends art, science, and emotion to raise awareness about the importance of this marine plant and the threats it faces, – says Ana Miletić Miloš, Senior Associate at Sunce’s Nature Conservation Department and one of the key organizers of the event.
Giving a voice to posidonia
On the façade of the Arsenal, visitors will witness a conversation between a sailor and Posidonia. Though hidden on the seabed and often unnoticed, this seagrass is the foundation of a healthy Adriatic. In the light show, it takes on a human form and voice, inviting the sailor to hear its call through song.
– We gave Posidonia a voice (and a body) to raise awareness in a unique way about how vital it is for our lives. It’s astonishing how little people know about it, given its crucial role in the marine ecosystem, –Miletić Miloš emphasizes.
These underwater seagrass meadows are truly the lungs of the sea: one square meter can produce up to 14 liters of oxygen daily. They stabilize the seabed, reduce beach erosion, enhance water clarity, and serve as nurseries where countless marine species feed, breed, and grow. Posidonia also stores large amounts of carbon dioxide, helping regulate the climate.
Capturing all of this in just a few minutes on one of Hvar’s most iconic buildings was a real challenge for Tomislav Brđanović, the author of the light show.
– Working on this story was a challenge because this is the first AI-generated film of this length in our country. The technology we used was demanding and unpredictable, but it opened entirely new possibilities for storytelling. As a child, I loved the sea and diving through posidonia meadows – while many feared that ‘seaweed.’ This project brought me back to that childhood and let me explore the posidonia issue in a new way, using a technology many now fear. I believe we can move forward –embracing new tools while preserving the nature we’ve been given, – Brđanović shares.
A message for sailors and sea lovers
Although the light show aims to inform everyone, one of the key target groups is sailors, because, unfortunately, they cause the most damage. Anchoring boats and yachts is one of the main reasons posidonia meadows are disappearing.
– As the number of vessels on the Adriatic during tourist season far exceeds available moorings, many still drop anchors freely onto the seabed. Research shows that a 50-meter yacht can destroy up to 1,500 m² of Posidonia in a single anchoring – that’s almost a quarter of a football field! – explains Zrinka Jakl, Head of Sunce’s Nature Conservation Department.
Where you anchor matters: on sandy bottoms, the impact is minimal, but in posidonia meadows, the damage is devastating for biodiversity and marine productivity. Learn more about Posidonia and practical anchoring guidelines in our leaflet, “Posidonia: The Mediterranean’s ‘super plant’.” In the past two months, we’ve distributed it to charter companies, sailors, concessionaires, and sea enthusiasts – and it will also be available at the Hvar light show.
The leaflet and this event are part of the Interreg BIOPRESSADRIA project, where Sunce, along with Croatian and Italian partners, develops strategies to reduce tourism’s negative impact on coastal and marine biodiversity.
Photo opportunities and prizes
On the evening of August 29, visitors can not only enjoy the spectacular light show but also visit Sunce’s info stands in Veli đardin park by the sea.
– It’s a great chance to learn more about Sunce’s work, membership, and volunteer opportunities. Those inspired by our message can even make a donation – your support is crucial to protecting Posidonia and the sea, – says Bruna Tomić, Assistant at Sunce’s Communications and Advocacy Department.
In addition, a photo backdrop will be set up in front of the Hvar Tourist Board office at Trg Svetog Stjepana 42, giving visitors a chance to ‘dive’ into posidonia! Snap a picture in front of the backdrop, share it in your story, tag Sunce and win posidonia-inspired prizes.
– Take a photo in front of the posidonia meadow and the message: Every breath you take, every fish you eat… It’s thanks to Posidonia! Help us raise collective awareness. We hope this event will inspire sailors and sea lovers to ask themselves next time: “And where do I anchor?” See you Friday, August 29, in front of the Arsenal! – Tomić concludes.
