Here’s the latest find-out of the UM-led Spot the Alien Fish Campaign: 

It seems that the population of alien rabbitfish, also known as the dusky spinefoot, has exploded in Malta’s rapidly warming waters, that have reached over 30°C in mid-July 2024. 

This type of fish with venomous spines has become so common that local fishermen have even found a nickname for it – qawsalla (rainbow) – because of its changing colours. 

Prof. Alan Deidun from the Department of Geosciences, who leads the campaign, said the rabbitfish is originally from the Red Sea and has been present in Maltese waters for about 15 years.

Whereas previously, the species' numbers were kept in check by the cold winter sea temperatures, which they couldn’t survive, with the rising temperatures of Maltese waters, this alien species has now established itself.

The Spot the Alien Fish citizen science campaign is collaborating with Ambjent Malta to create a cookbook on how to cook alien species, including the rabbitfish, as a strategy to control their population growth. 

"The rabbitfish can be cooked and eaten, but its venomous spines must first be removed," Prof. Deidun said. 

Maltese waters recently reached temperatures of 31.2°C, according to data from Dr Adam Gauci of the Oceanography Malta Research Group, who manages the marine monitoring network. Such temperatures are typically not seen until August. In 2022, the waters reached 30°C by the end of July.

“It is happening earlier and earlier. These warmer waters are attracting species from the Eastern Mediterranean to the West and North,” Prof. Deidun said. "Any fast change in the natural system is cause for concern as indigenous species do not have time to adapt."