White foam-like slicks besiege Sliema coast, but experts say it's not fish slime
The substance could be bilgewater from a vessel further out to sea, according to one expert
Large slicks of foam-like white residue washed up in Sliema on Saturday morning, with one expert speculating the substance could originate from a ship beyond Gozo.
Photos and videos taken from close to the Sliema promenade show large slicks of dense white residue bobbing on the surface of the water close to the rocks on both sides of Chalet, leaving the popular bathing site conspicuously empty of swimmers.
“Nobody’s jumping in the sea, it’s everywhere,” said one concerned resident, noting that the residue was visible from around 7.30am.
While Sliema has been beset by fish slime from tuna farming operations in recent years, experts Times of Malta spoke to said it could not have originated from fish farms.
“It’s definitely not tuna slime,” said one expert, noting there were “no tuna fish in pens at the moment”.
The production of bluefin tuna kicks off in May and June, when wild adult fish weighing typically around 100kg are captured in the southern Mediterranean before being transferred to pens off the coast of Malta, where they are fattened for around six months.
The expert noted that he had observed the white substance on Friday, “coming in from beyond Gozo” while travelling on the ferry back to Malta.
He speculated that the substance could be bilgewater – typically a mixture of engine oil, fuel and water that collects in the lowest internal compartment of a vessel – dumped by a ship further out to sea.
The disposal of bilgewater is highly regulated under international law, and residual oil is required to be processed to below 15 parts per million before any discharge at sea is allowed.
A spokesperson for the fisheries industry also said the substance could not have originated from fish farming operations.
In recent months, the sea at Sliema has been more under siege from domestic contaminants than those out to sea, however.
In April, residents were alarmed by foul-smelling murky brown liquid, believed to be raw sewage, extending into the sea from under the promenade near Sliema ferries.
And the month before, construction waste and sewage overflow seeped into the sea along Sliema’s coastline after large amounts of demolition waste obstructed the sewer line.
Earlier this month, construction authorities shut down a large hotel project on The Strand after large volumes of water from the foundations of the site were dumped onto the promenade, extending across the main road.