in-cyprus 20 August 2025
The Mediterranean Sea recorded its hottest July on record with average surface temperatures reaching 26.68°C, as hundreds of Red Sea species establish populations in the rapidly warming eastern basin, marine researchers told AFP.
Water temperatures reached 29°C at 30-metre depths off Turkey’s Antalya coast, where surface temperatures hit nearly 32°C this week, according to diving instructor Murat Draman.
“We were at a depth of 30 meters this morning and the water was 29C,” Draman told AFP, comparing current conditions to August temperatures of 25°C in the early 2000s.
The Mediterranean ranks among the world’s fastest-warming seas, with data from Mercator Ocean International research centre confirming record temperatures for June and July this year.
Red Sea species migrating through the Suez Canal are disrupting Mediterranean ecosystems, with the venomous lionfish now appearing in groups of 15-20 per dive compared to occasional sightings a decade ago.
“They are big predators. Small fish like gobies suffer a lot, we hardly see them anymore,” Draman told AFP.
Westward migration
Professor Gil Rilov from Israel’s Oceanographic and Limnological Research institute confirmed invasive species are establishing permanent colonies across the eastern Mediterranean.
“The invasion started almost immediately after the opening of the Suez Canal in 1869,” Rilov told AFP. “But now it’s getting warmer, and also (in 2015), the canals got deeper and wider, so more and more new species move in every year.”
The rabbitfish has recently colonised waters off Malta, more than 1,700 kilometres from the Suez Canal, indicating continued westward expansion.
Many native eastern Mediterranean species have disappeared due to excessive warming and competition from invasive species, Rilov told AFP.
“What is happening here will happen in five, 10 or 20 years in the north and west of the Mediterranean,” he told AFP.
Complete tropicalisation projected
Scientists project the entire Mediterranean could become “tropicalised” by 2100 under worst-case climate scenarios, according to research published in Proceedings of the National Academy of Sciences in April.
The study warned Atlantic Ocean warming could introduce west African species to the western Mediterranean by 2050.
Draman told AFP that invasive species must be kept from protected marine areas to preserve biodiversity.
“It is clear that with the absence of Mediterranean predators, species such as lionfish are very comfortable here and their population is increasing year on year,” he told AFP. “In the Red Sea, lionfish have predators. There are sharks and barracudas. Here, we have none of that.”
(Source: phys.org)
