Updated 2.15pm with fish-farmers' reaction -
A major fish farm operator was temporarily shut down last month after it was caught using a type of feed that is a leading cause of the much-maligned ‘sea slime’.
Mare Blu Tuna Farm Ltd was fined and had its operation suspended for a week after a routine inspection found a consignment of bait fish feed that had not been properly thawed, sources within the environmental regulator said.
This could have resulted in excessive fatty residue forming an oily slick on the sea surface once it was lowered into tuna pens.
The seven-day suspension of feeding activity stunts the growth of penned tuna and impacts the operators’ profitability.
The Federation of Malta Aquaculture Producers (FMAP) said none of its members had its licence suspended. It hit out at the feeding practices of non-members and said it had reports by independent experts showing how some feeding practices do not conform with best environmental practice.
In recent weeks, photos have been widely shared on social media showing patches of ‘slime’ along different stretches of the island’s coastline.
Many questioned whether this was the result of illegal feeding practices at fish farms.
The issue has plagued beaches in recent years, prompting the fish farm operators’ lobby to commit to a series of self-regulatory measures that would run during the summer months.
Replying to questions, a spokeswoman for the Environment and Resources Authority told Times of Malta that of the last three reported ‘slime’ sightings, inspectors had confirmed that fish farm feed was at least partially responsible in two instances.
Recent reports of ‘slime’ in Mellieħa had been the result of patches of oily residue from fish farm feed which had also mixed with “lasting foam”, a natural phenomenon, the spokeswoman said.
A similar sighting in Sliema earlier this month had been the result of lasting foam which developed from “micro-algal blooms”, she added.
Fish farm feed was at least partially responsible in two instances
And ‘slime’ reported in Marsascala had been the result of oily residue from fish farm feed interacting with algae, she noted.
The spokeswoman said that all fish farm operators were inspected “at least three times a week” by ERA officials to ensure that permit conditions were followed. She also provided Times of Malta with photos that showed efforts being made to reduce fat-laden residue from the fish feed from reaching the sea.
One photo showed the feed used in the past, which is covered in a yellow fatty substance. The second featured the same type of feed but after it had been thawed and the fat removed prior to being fed to the tuna.
“As a result of discussions held between ERA and the tuna farm operators, the feeding methods were improved through better thawing procedures, resulting in a drastic reduction of thaw water and fish oils in the surrounding sea,” the spokeswoman said.
Authority officials, she noted, “constantly” monitored fish farm operations both onshore and offshore.
Federation hits out at 'unacceptable practices' by non-members
The Federation of Malta Aquaculture Producers (FMAP), representing some fish-farmers, said none of its members had had its permit suspended for non-compliance with environmental conditions. Indeed, over the past months, Tuna Ltd, Fish and Fish Ltd, MFF Ltd, Malta Mariculture Ltd and Ta’ Mattew Fisheries Ltd had dedicated substantial resources to ensure that their operations did not have a negative impact on the environment.
The federation said that some of the pictures appearing in the media had nothing to do with its members.
"The federation is in possession of reports by independent experts showing how some feeding practices still being carried out today do not conform with best environmental practice," it said.
It insisted that all operators should be subject to the same environmental conditions. What was not allowed for some operators should not be allowed for others and it should always be the best practices which should apply.
It was not acceptable, the federation said, that some operators had to have on-shore facilities while the authorities allowed others to carry out all their operations at sea.
It argued that what was acceptable in the past was not necessarily acceptable now, and it, therefore, needed to be ensured that all operators were suitably equipped for current needs. This was currently not the case.
ERA Gives more detailed explanation
In a further, more detailed explanation on Wednesday, ERA said there are various types of sea surface phenomena including lasting foam, mucilaginous formations and oily sea slime.
Lasting foam is a natural phenomenon and the result of micro-algal blooms, which release natural detergents and lead to foaming forming at surface. This has been reported in various parts around Malta and in various parts of the Mediterranean and elsewhere.
Mucilaginous events may also result from natural phenomena and like lasting foam, are usually caused by micro-algal blooms and produce slimy formations.
On the other hand, oil slicks and oily sea slime usually arise from manmade sources, including fish farms. The latter is usually distinguished from its consistency and foul smell.
"All the above events have direct but different impacts on the environment and sometimes on humans. It may be that the occurrence of lasting foam or micro-algal blooms interact with the oily residues released by fish farms, to aggravate the resultant environmental impacts," the Authority said.
All fish farm operators are inspected at least three times a week be ERA officers to ensure that permit conditions are observed. Fish remnants resulting during the feeding process are collected by cleaning vessel that patrol the perimeter of the fish farms.
"All feeding procedures are being undertaken in such a manner as to reduce fat-laden thaw water from the baitfish, from reaching the sea."
As a result of discussions held between ERA and the Tuna Farm operators, the feeding methods were improved through better thawing procedures, resulting in a drastic reduction of thaw water and fish oils in the surrounding sea, it insisted.
"ERA’s officers constantly monitor fish farm operations both on-shore and off-shore and hold frequent meetings with operators in order to ensure practices that cause the least amount of disturbance to the natural environment are being followed.
Apart from the Compliance and Enforcement Order, 15 fines were imposed.