‘Flesh-eating’ bacteria is spreading across Europe’s beaches

Experts have warned that rising sea temperatures are increasing the risk of potentially dangerous Vibrio bacteria in European coastal waters, with parts of the Mediterranean becoming more favourable for the microorganisms as climate change accelerates.

The bacteria, which occur naturally in warm, brackish coastal waters, have long been present in Europe’s marine environment. However, scientists say warmer seas are extending both their geographical range and the period during which they can reach higher concentrations.

Environmental consultant Arif Gasilov said the bacteria are not a new threat but that changing climatic conditions are making them more prevalent. According to him, the greatest risk is found in areas such as river mouths and lagoons, where warm water combines with lower salinity—locations that are also popular with swimmers.

Health experts are particularly concerned about Vibrio vulnificus, a strain sometimes referred to as “flesh-eating” bacteria because, in rare cases, it can cause severe soft tissue infections.

People with open wounds, weakened immune systems or chronic health conditions are considered to be at the highest risk of infection. In serious cases, the bacteria can lead to necrotising fasciitis, a rapidly progressing infection that destroys surrounding tissue, or enter the bloodstream and cause sepsis. Some severe infections may require limb amputation.

The European Centre for Disease Prevention and Control (ECDC) has warned of an elevated risk of Vibrio infections during periods of extreme heat, particularly in shallow coastal waters.

Scientists note that the Mediterranean Sea is warming significantly faster than the global average, creating increasingly favourable conditions for bacterial growth. While the Mediterranean’s relatively high salinity has historically limited the spread of the most dangerous Vibrio strains, researchers say changing temperatures and salinity patterns could alter that balance.

Hatim Aznague, an analyst at the Union for the Mediterranean, said countries bordering the sea should adopt a coordinated regional approach to monitoring and responding to the threat, arguing that marine environmental challenges do not respect national borders.

Experts also pointed to the growing presence of invasive marine species as another consequence of warming seas. In Greece, authorities have reported an increase in the population of the silver-cheeked toadfish, a highly toxic species believed to have migrated from the Indian Ocean through the Suez Canal into the Mediterranean.

The fish contains tetrodotoxin, a powerful neurotoxin that can cause paralysis, heart failure and respiratory failure if consumed. Greek authorities have introduced financial incentives for fishermen to catch the species as part of efforts to limit its spread.

Scientists say strengthening water quality monitoring, improving early warning systems and reducing pollution entering coastal waters will be essential in managing the growing risks posed by warming seas and harmful marine organisms.