Scientists warn marine heatwave in Europe could kill off some species

LISBON • High temperatures across Europe last month have unleashed a prolonged marine heatwave in the Mediterranean Sea that could ravage ecosystems and kill off several species in the coming weeks, scientists have warned.

The extreme heat in recent weeks has already sparked wildfires and led to thousands of heat-related deaths in Europe, but that warmth has not been limited to the land.

The warmer air, along with shifting ocean currents and a stable sea surface, has warmed coastal Mediterranean waters several degrees Celsius beyond the average temperature of 24 deg C to 26 deg C for this time of year.

Waters between Spain's Balearic Islands and the Italian coast were up to 5 deg C warmer than at the same time last year, Spain's Amet weather agency said on Friday - while also warning that temperatures around the Spanish coast would be 3 deg C to 4 deg C higher until at least mid-August.

Marine heatwaves are becoming more frequent due to climate change, adding pressure to ecosystems already struggling from overfishing and plastic pollution.

Ocean scientist Jean-Pierre Gattuso said water near the French coastal city of Nice was measured at 29.2 deg C on July 25 - around 3.5 deg C higher compared with the same day last year.

"This is an absolute record since at least 1994 and very likely earlier," he said.

Marine heatwaves also struck the Mediterranean from 2015 to 2019, leading to mass die-offs of marine life, according to a study from Spain's Institute of Marine Sciences. This year's heatwave is worse.

REUTERS