Comino’s hidden plant wealth revealed in landmark study

A landmark scientific study has revealed that Comino’s plant biodiversity is far richer than previously documented.

The study comes with a timely reminder about environmental threats that could irreversibly alter one of Malta’s most sensitive natural sites.

The research titled The Vascular Flora of the Comino Archipelago published recently in the journal PhytoKeys by botanists Stephen Mifsud, Daniel Pavon and Frédéric Médail, is the first full inventory of the island’s vascular plant life.

Vascular plants are those plants, which have specialised tissues for the transport of water, minerals and food.

It combines historical botanical records dating back to the mid-19th century with extensive field surveys carried out between 2008 and 2025.

In total, the study recorded 490 vascular plant species across Comino and Cominotto, including 21 endemic species and 58 species under strict legal protection. Among the most striking findings were 78 plant species never before recorded on Comino, and two species new to the Maltese islands.

These include previously undocumented taxa such as Daucus carota subsp. commutatus var. tenuisectus (a wild carrot form, known in Maltese as zunnarija selvaġġa) and Catapodium pauciflorum, a rare grass with no widely used Maltese common name. The study also highlights a strong population of Hornungia procumbens, an uncommon coastal species.

160 plant species lost

Despite these discoveries, the researchers also document a worrying ecological loss. Around 160 plant species historically recorded on Comino have not been observed for decades and are now considered locally lost.

The island’s ecological integrity is increasingly undermined by intense seasonal tourism, particularly concentrated at the Blue Lagoon and Santa Marija Bay. During peak summer months, daily visitor numbers can reach between 10,000 and 12,000, placing extreme pressure on coastal habitats.

One of the most affected areas is the sand dune system at Santa Marija Bay, where visitors often bypass protective cordons to sunbathe directly on fragile dunes. This trampling has led to severe habitat degradation and is believed to have contributed to the disappearance of Euphorbia peplis, a rare dune plant now considered extinct on Comino.

Beyond visitor pressure, the study raises concerns over proposed development projects that could fundamentally change the island’s character. These include plans to convert the existing hotel into a luxury resort and proposals to turn bungalows at Santa Marija Bay into privately owned villas.

The authors warn that such developments would likely require permanent infrastructure upgrades, including roads, vehicle access and support services, effectively transforming Comino into a semi-urbanised settlement.

“The proposed conversion of Santa Marija Bay into a small private residential area, composed of some 16 villas replacing the old hotel’s bungalows, would definitely increase the risk of urbanisation at this quasi-pristine Natura 2000 site,” the authors warn.

The research also flags the spread of invasive alien species. The Tree of Heaven (Ailanthus altissima, known in Maltese as siġra tas-sema) is expanding rapidly through Wied l-Aħmar valley. Meanwhile, large-scale planting of non-native Aleppo pine (Pinus halepensis, known locally as żnuber) is altering native garigue habitats and displacing endemic plant communities.

According to the authors, these pressures are compounded by inappropriate afforestation schemes that introduce genetically non-local plant material, further disrupting ecological balance.

The study concludes that Comino’s biodiversity can only be safeguarded through a coherent, science-based management strategy. While the researchers recognise that visitor caps introduced in 2025 have helped reduce overcrowding, they stress that strict enforcement, habitat protection and long-term planning are essential if the island’s remaining “quasi-pristine” ecosystems are to survive.