Malta’s coastal waters are rapidly changing as marine heatwaves drive the spread of invasive species, with some bays now becoming “alien worlds”, according to leading marine biologist Alan Deidun.According to a report by Times of Malta, Deidun said rising Mediterranean temperatures are placing increasing pressure on native marine life while creating ideal conditions for invasive species to thrive.“Invasive species are spreading like mad in bays like Wied iż-Żurrieq, Xagħra, Marsascala and Marsaxlokk, which are becoming alien worlds,” he warned.Recent temperature readings showed underwater temperatures last Thursday were higher than 90% of all measurements previously recorded for that date. Researchers have also documented annual marine heatwaves at depths of up to 30 metres off Mġarr ix-Xini between 2019 and 2023.The warming seas are affecting local ecosystems, with sea urchins retreating to deeper waters and some coral colonies dying off entirely.Scientists are also raising concerns about invasive pufferfish species, particularly the silver-cheeked toadfish, whose numbers have surged in Maltese waters over the past two years.The fish contain the powerful neurotoxin tetrodotoxin and should never be eaten, even after cooking. They can also damage fishing equipment and pose a growing challenge for fishermen. Deidun described the phenomenon as the “tropicalisation of the Mediterranean”, warning that climate change is transforming local marine environments faster than many expected.Have you noticed any unusual marine life while swimming?•