In the serene waters surrounding Alonissos, a Greek island nestled in the eastern Aegean Sea, a group of dedicated volunteer divers are sounding the alarm on mounting marine pollution. As part of an EU-backed seabed cleanup project, the divers are collecting everything from crumbling plastic bottles and abandoned tyres to rusting metal debris—evidence of a growing threat to one of Europe’s most fragile underwater ecosystems.

Though Alonissos is renowned for its crystal-clear blue-green waters and is home to Europe’s largest protected marine park, the waste pulled from its seabed represents just a fraction of the massive pollution problem facing the Mediterranean. Every year, tens of thousands of tons of waste—mainly plastic—sink into these waters, disrupting marine life and threatening biodiversity. The diver-led cleanup offers only a glimpse into the scale of the crisis.

The National Marine Park of Alonissos, established in the early 1990s, is a sanctuary for over 300 fish species, dolphins, sea turtles, and one of the last surviving populations of the endangered Mediterranean Monk seal. The park's rich biodiversity has made it a center of environmental awareness for both residents and tourists. According to Theodora Francis, a 31-year-old diver involved in the operation, while some areas remain relatively clean, others—especially near Votsi port, a hub for fishing and tourism—are heavily littered.

Recognizing the importance of preserving its marine habitats, Greece has pledged to create two new marine parks—one in the Aegean and another in the Ionian Sea. These efforts are part of a larger national strategy involving 21 eco-initiatives worth €780 million, aimed at protecting the coastal ecosystem. In alignment with EU conservation goals, the country is moving to expand marine protected zones to cover 30% of its waters by 2030, introducing stricter regulations on fishing, tourism, and offshore energy development.

The cleanup was spearheaded by Aegean Rebreath, a Greek marine conservation group led by George Sarelakos, who stresses the importance of personal responsibility in environmental stewardship. “We believe individuals have the power to drive change. It's about showing the world that collective action begins with each of us,” he said. Their approach combines community engagement with direct action, bridging the gap between policy and grassroots activism.

For Francis and her fellow divers, Alonissos serves as a blueprint for marine conservation. “If more islands took an interest in protecting their waters like Alonissos, we’d see this kind of success replicated across the region,” she said. The island’s commitment to sustainability could inspire a broader movement to protect the Mediterranean’s rich marine heritage from the escalating dangers of human pollution.