Barracuda, parrotfish and fireworms: the changing Mediterranean

Anyone who has snorkelled Sardinia for twenty years has watched it happen live: the Mediterranean is warming faster than the ocean average, and as temperatures change, so do the tenants. Some newcomers are a spectacle; others just call for a little extra care. A reasoned guide to what you might meet this summer.

The new protagonists (harmless and photogenic)

The Mediterranean barracuda now overwinters routinely even in the north: midwater schools near points and shallows are among the island’s most scenic encounters, and entirely harmless to swimmers.

The parrotfish, historically “African”, is now at home in the Sulcis and moving up the coast: the green-blue males and reddish females graze the rocks like on a tropical reef. In the south-west, between Carloforte and Chia, sightings are now a daily event in summer.

The one to watch: the bearded fireworm

The bearded fireworm (Hermodice carunculata), with white tufts on a reddish body, is the most talked-about range expansion of recent years in southern Italian seas, Sardinia included. It does not attack: the problem is its stinging bristles, which lodge in the skin on contact.

There is only one rule: look, don’t touch — never with your hands, not even with gloves. If you do make contact, lift the bristles off with tape or tweezers, rinse with seawater and apply heat; if the reaction spreads, see a doctor. With a mask and a little attention it remains a rare, very manageable encounter.

What it means for snorkellers

Longer seasons (the water stays above 20 °C well into October), more “tropical” encounters and a few new precautions: that is the balance sheet. The best way to enjoy the change is also the most useful one: observe and report. Citizen-science platforms such as iNaturalist use snorkellers’ photos to map species expansion — your snapshot can become a scientific data point.