There have been numerous scientific studies and reports on such sea slime, especially in countries like Spain and regions like the Northern Adriatic which conclude that such slimy exudates might be a by-product of the bloom (large concentrations) of microscopic phytoplankton cells belonging to particular species, marine biologist Alan Deidun told The Malta Independent yesterday.

This newspaper contacted the university professor after reports emerged yesterday of a new wave of sea slime hitting the coast of St Julian's and Sliema.

Deidun said such sea slime was probably not a product of fish farms but rather a natural foam-like by-product known technically as "surfactant", whose production in favoured by churning waves which concentrate the normally dispersed phytoplankton cells.

"Currently most fish farms are empty, especially since the tuna season starts in May, with most of the caged tuna being killed and exported by November/December of each year," said Deidun.

"If this sort of slime appeared in summer, there would have been more reason to think this came from fish farms, although even in summer, the natural production by phytoplankton cannot be completely discounted."

"When the phytoplankton species responsible for the foam production are in bloom, they produce a by-product, surfactant,-which is only produced by a small group of phytoplankton species and which is generally innocuous, although unsightly to some." The weather also has an impact on this product; when there are strong winds the currents churn and accumulates the phytoplankton and this type of slime.

The question still remains how and why such phenomenon are becoming more frequent, and there is a need for more research.

So far, only preliminary tests have been conducted and there has not been any extensive study in such phenomenon.

Deidun explained that it is not easy to study such sporadic occurrences, as there would have to be a group of scientists ready on a boat at the right time and moment to collect the data to be able to send it abroad to be analysed. "It is also a question of having scientists who are specialised in the study of plankton, which there are only a handful. I am aware that ERA is looking into this and has also contacted the University of Malta and laboratories abroad."

This newspaper also contacted the Federation of Maltese Aquaculture Producers, which also said that the slime was not coming from fish farms. FMAP CEO Charlon Gouder said this is a phenomenon, and that such substance is not only seen around Malta, but also abroad. He said that at this time of year fish farms are not operating so it is not coming from them. He said that the ERA is looking into this new phenomenon, and will hopefully find out the cause. "It could be a natural phenomenon."

PD Leader Godfrey Farrugia, speaking with this newsroom however, questioned why sea slime is always seen on the East side of the island and not the West side, highlighting the fish farms present at Sikka il-Bajda.

While acknowledging that the slime could very well have come from phytoplankton, one cannot forget the slime situation caused by the fish farms since 2016, he said.