Action needed to stem tide of disease in salmon farms

NCE again, disease in Scotland’s salmon farms has raised its ugly head. It is bad news for the industry, but potentially also for our wild salmon, should they swim into such troubled waters.

The outbreak of Amoebic Gill Disease (AGD) on farms in the Hebrides and Wester Ross presents a threat that may well call for intervention by the Scottish Government. AGD, a mucusproducing condition that suffocates the fish, is a nasty business for which salmon farms were supposed to be better prepared.

True, there is not much they can do about unusually high seawater temperatures, which do much to produce the disease. Crowding and poor water circulation in cages have also been identified as causes in cases abroad, where the problem has hitherto been more prevalent. Prevention is one thing, containment another, and it is incumbent on farms to sound the alert immediately, even if this amounts to broadcasting news that does them no favours.

Fish-farming has its foes, but also its friends. It is an economic growth sector. By providing jobs, it keeps people in areas threatened by depopulation. But it cannot do so at a risk to wild salmon nor while presenting a threat to Special Areas of Conservation.

Wild salmon interests have called on the Scottish Government to order the immediate slaughter of the farmed stocks in question. A drastic step indeed, particularly since we are dealing with an unquantified threat, due to the difficulty of diagnosis in wild fish.

However, wild salmon is so important for Scotland that the Scottish Government will have to examine all options and, at the very least, seek assurances about early notification while also investigating research into better treatments. Certainly, the disease needs to be brought under control immediately, with watertight safeguards in place before next spring when wild salmon smolts migrate.