PHYSALIA PHYSALIS IN THE CENTRAL MEDITERRANEAN SEA: RECENT OBSERVATIONS IN RELATION TO MASS STRANDINGS OF VELELLA VELELLA AND SURFACE CIRCULATION DYNAMICS

The Portuguese man-of-war, Physalia physalis (Linnaeus, 1758), is a pleustonic siphonophore distributed throughout tropical and subtropical oceans. Although the species is occasionally recorded in the Mediterranean Sea, its occurrence is generally linked to episodic advection driven by winds and surface currents. Here, we report observations of P. physalis in the central Mediterranean between 6 February and 6 March 2026, coinciding with massive strandings of the pleustonic hydrozoan Velella velella. A negative North Atlantic Os-cillation (NAO) phase likely facilitated Atlantic water inflow and eastward transport into the Mediterranean. A drifter trajectory from the southern Tyrrhenian Sea indicated temporary retention near the Lipari coast. These records likely indicate a transient influx of P. physalis, rather than a stable Mediterranean population.