ROB Edwards’s article in the Sunday National, "Use of drugs at fish farms rises 50 times in six years", contains significant data, which should generate a response from Scottish ministers, who continue to give enthusiastic, if qualified, support the expansion of the fish farming industry.

The reported tonnages relate to antibiotic treatments (Florocol and Aquatet) for which the dosage levels are measured in milligrams. These drugs are supplied in powder form. The powder has to be mixed with the fish feed. Operators are advised to wear gloves, masks and goggles when handling them. The deposition of some of the treated feed reaching the seabed is difficult to avoid.

In 2020, a single fish farm in Argyll used over three tonnes, or 83% of all reported use of Aquatet in that year, and a fifth of the total for the six-year period. As the article shows, overall usage increased each year between 2016-21, apart from single-year exceptions for each medicine (though in each case the usage was well above the 2016 levels).

Of course, these are not the only treatments the industry has to use to try to combat diseases in their fish stock. Others include different antibiotics, pesticides, disinfectants and mechanical equipment (eg, thermolicer and hydrolicers used against sea lice). Such treatments can themselves cause fish mortality.

According to Sepa data, over five million salmon deaths were reported on fish farms in Scotland during 2021. The range of causes reported by operators includes amoebic gill disease, cardiomyopathy syndrome, complex gill disease, fungus, Pasteurella, sea lice related, yersiniosis, post treatment, handling and equipment failure. Predation is also a reported cause (about 3% of mortalities reported). As we know from Covid, infections tend to modify with time and Scotland can claim its own species – Pasteurella skyensis discovered a few years ago on west coast fish farms.

It’s clear that the industry has a problem dealing with the inevitable health issues that arise in any intensive animal farming. It has been subject of a number of Parliamentary inquiries arising from environmental and welfare concerns. One concluded in a report published in 2018 that “…..if the industry is to grow, the Committee considers it to be essential that it addresses and identifies solutions to the environmental and fish health challenges it faces as a priority.”

Manifestly the challenges for the industry, the animals in its stewardship and the marine environment continue.

The spokesman for Mowi quoted in the article emphasises the idea that they are caring for the fish. Sounds as if what they do is in the fish’s best interests! Fundamentally, anyone who confines a sea-going animal in a cage, treats them with chemicals, causes them stress through various procedures and interventions, has lost the caring argument.

Not surprising then that supporters of the industry have given up the "pristine seas" mantra that used to be part of the marketing brand for Scottish farmed salmon. Even the claim of sustainability is a no-go area. Across the world, nations and states are either imposing bans on new open water pens or are investigating closed containment.

In a recent report requested by Scottish ministers into the future regulation of aquaculture in Scotland, Professor Russel Griggs made the following startling observation about the current regulatory system: “The degree of mistrust, dislike, and vitriol at both an institutional and personal level between the industry (mainly finfish), certain regulators, parts of the Scottish Government and other stakeholders, is at a level that I have never seen before which makes the current working relationships within the sector challenging.”

Could it be that this is a symptom of the pressures felt by those who are trying respectively to regulate, or to defend, this industry?

Perhaps it can neither be regulated nor defended.
Roddie Macpherson