Health alerts and sea access bans are increasing across Europe and the United States as warmer ocean temperatures and rising coastal pollution create a more hospitable environment for the Vibrio bacterium, including the dangerous strain Vibrio vulnificus. This bacterium, sometimes referred to as "flesh-eating bacteria," can cause severe infections if it enters the bloodstream through open wounds, potentially leading to sepsis, amputations, and death.
Record-high sea temperatures, particularly in the Mediterranean, are a primary driver of this trend. The Mediterranean Sea is warming approximately 20% faster than the global ocean average, according to climate analysts. While the region's historically salty waters have offered some protection, experts warn that rising temperatures and changing salinity levels could allow Vibrio strains to proliferate further.
"Warmer water, especially where it is less salty, at river mouths and in the lagoons they enclose, becomes more conducive to pathogenic bacteria," Hatim Aznague, a climate analyst at the Union for the Mediterranean, told Euronews. Most Vibrio bacteria are harmless, but strains like Vibrio vulnificus pose significant health risks.
In the United States, Florida has been a hotbed for Vibrio vulnificus infections. In 2025, health officials confirmed 29 cases and at least five deaths in the state. Louisiana also reported an unusual surge, with 26 hospitalizations and five fatalities. A notable case involved Genevieve Gallagher, a 49-year-old Florida woman who contracted a severe infection after swimming at Quietwater Beach in July 2025, nearly requiring the amputation of her leg. More recently, a 17-year-old Florida teenager, Joziah Thompson, is fighting for his life after contracting the bacteria while swimming with a small cut on his leg.
Europe has also seen an increase in cases. Germany recorded its first fatality of the summer bathing season in July 2025, when a 68-year-old individual with underlying health conditions contracted the bacteria. The European Centre for Disease Prevention and ECDC) warns that Vibrio infections become more likely during summer heatwaves and in shallow coastal waters.
Experts at the ECDC recommend several precautions to reduce the risk of Vibrio infection. These include covering any open wounds with waterproof bandages before entering coastal or brackish waters, or avoiding swimming altogether if such protection is not possible. It is also advised to wash hands and exposed skin thoroughly after contact with seawater. For those who consume seafood, avoiding raw or undercooked shellfish is recommended, as the European Food Safety Authority (EFSA) notes that Vibrio can contaminate seafood.
The rise in Vibrio presence also poses a threat to Europe's significant tourism industry. Beach closures can result in immediate financial losses and long-term damage to a destination's reputation. Aznague emphasized that for coastal economies, the shoreline "is the economy," and a closed beach represents a tangible cost of climate impact.
In addition to Vibrio concerns, some stretches of English coastline have been classified as having "poor" water quality, with 20 areas flagged by Locals Insider as not recommended for swimming due to contamination from sewage and dumped waste. This rating, the lowest issued by the Department for Environment, Food and Rural Affairs (Defra), underscores broader issues affecting water quality at popular tourist destinations.