Strong marine heatwave grips Malta’s waters, as sea temperature hits 29°C
The rising sea temperatures are threatening Malta’s marine life, a leading oceanographer has warned
Malta’s waters are experiencing a strong marine heatwave, with sea temperatures of almost 29°C placing marine life under threat, a leading oceanographer has said.
Aldo Drago, a professor of oceanography, said the sea surface temperature around the Maltese islands rose from 27°C on July 14 to 28.8°C on July 20, just six days later.
This is roughly 3.7°C higher than the long-term average for this time of year, Drago said.
Last Friday, the sea temperature rose by an “exceptional” 0.91°C in the span of just 24 hours. In a typical year, the sea would only warm by 2.8°C over the entire month between mid-June and mid-July.
Drago described the sea as “a vast solar collector,” pointing to how raising the temperature of a 20 kilometre-wide strip of sea surrounding Malta by one degree Celsius would have required 50 billion kilowatt-hours of heat energy.
“This is comparable to around ten years of Malta’s domestic electricity production,” he said.
The prolonged rise in the sea temperature is placing “considerable stress on Malta’s marine ecosystems, including Posidonia Oceanica seagrass meadows, coral communities and rocky reef habitats,” Drago said.
“Sustained high temperatures can increase the incidence of disease, cause widespread [marine life] mortality, and facilitate the spread of non-native tropical species,” he said.
The fishing and aquaculture sectors were also bearing the brunt of the heatwave, he said, with many species forced “to migrate into deeper, cooler waters, making catches less predictable for small-scale fishers”.
Fish farms, meanwhile, were also more likely to experience disease outbreaks and algal blooms, he said,
Last month, marine biologist Alan Deidun said heatwaves were driving the spread of invasive marine species into Maltese waters, warning that Malta’s bays were “becoming alien worlds”.
In some areas, temperatures were eight degrees higher than the norm, Deidun said, describing the temperature increases across the Mediterranean as “beyond our wildest expectations”.
Malta is bracing itself for a fifth consecutive day of extreme heat, with the Met Office forecasting a maximum temperature of 42°C on Wednesday.