Fish farm operators are selling the slime collected in booms for various uses, including medicine, a representative for the Federation of Maltese Aquaculture Producers said. The slime is currently being exported and being refined, federation secretary John Refalo said. “It is a natural product – the slime is made up of fish oil residue from tuna feed like mackerel or sardines. The product starts to deteriorate if it is not collected immediately,” Dr Refalo explained. Fish oil is found in various health products on the market, Dr Refalo added.