Monaco sea temperature above 28°C for record 39 days
By Zak Jackson, MonacoViews Editorial
A marine heatwave of unprecedented duration is battering Monaco's Mediterranean coastline, with water temperatures holding above 28°C for 39 consecutive days and devastating local marine life.
For 39 days and counting, the waters off Monaco have remained above 28°C, a duration that specialists describe as without precedent at a human scale for a marine heatwave in the Principality. The Mediterranean, already under pressure from successive summer heat spikes, has offered no overnight relief, with surface temperatures refusing to drop to levels that would allow marine ecosystems to recover between episodes.
The consequences for Monaco's coastal flora and fauna are severe. Marine life in and around the Principality's protected zones, including the seagrass meadows and rocky reef habitats that extend along its shoreline, is under acute stress. Extended thermal events of this kind accelerate the bleaching and die-off of Posidonia oceanica seagrass, a protected species that underpins much of the local marine food chain, and push fish populations into deeper, cooler water or further along the coast.
Marine heatwaves are measured not just by peak temperature but by duration, and it is the persistence of this event that sets it apart from previous summers. Conditions of this kind, once considered exceptional, are becoming a recurring feature of the western Mediterranean in high summer, raising serious questions for Monaco's ongoing marine conservation programmes and for the long-term health of the bay.