Reference is being made to various sightings and reports of material in the sea that has been attributed to sea slime. The Environment and Resources Authority (ERA) would like to make a number of clarifications in order to avoid any further misunderstandings.

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.

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. In fact, Photo 1 in the link below portrays the amount of fat that was being generated as part of the tuna feeding process. The yellow matter seen in the photo emanates from baitfish that was insufficiently thawed and was resulting in a considerable amount of thaw water and oils being discharged in the sea. Photo 2 portrays a different feeding method, whereby residue related to feeding methods was also ending up in 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. See Photos 3 and 4.

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. Fifteen administrative fines and one Compliance and Enforcement Order have been issued against Tuna Farm Operators in 2019.

ERA emphasises that the collaboration of all fish farm operators is vital in ensuring no disturbance or damage is caused to natural habitats because of commercial interests.

Photos may be found here:​