Fishnish A off Mull saw ten 100m pens replaced with four 160m pens.
As well as the bigger pens and heavier moorings, Fishnish also introduced Midgard HDPE knotted nets and a new winch system, and trialled a smart feeding regime, in an investment of around £3 million.
Farm Manager Alastair Fraser said: ‘It was night and day compared to the previous set-up: so simple, less labour intensive, with less manual handling. The new winch system is another world and once we got the hang of it there was no going back.’
Ten winches are fitted to each walkway and operated remotely from a dedicated workboat, providing better net control and improving staff safety.
‘Dealing with three instead of 10 pens (we kept one spare for handling or freshwater treating) allowed us to stay focused on the task in hand and carry out any treatments much faster.’
The combined tonnage for Fishnish A and B, where half the crop was moved after six months, was just over 4,000 tonnes, said Fraser, quite an achievement given challenges which included the micro jellyfish that affected most of the sector between 2022 and 2023.
Fraser attributes the results to good husbandry as well as to the bigger pens, which provide lower stocking density and better water flow and oxygen.
The new feeding system, involving motorised smart spreaders, produced ‘fantastic results’, ensuring the whole population was fed at the same time, with feeding finished by 9.30am so the fish could go down to the depths of the pen.
With the fish harvested over summer, the team is now preparing for the next cycle and hoping to roll out similar infrastructure at neighbouring Fishnish B.
And while they will do some things differently, such as increasing the ratio of wrasse in the pens to better handle sea lice off Mull, they are convinced the new infrastructure has paid off.
‘The team realised they’d had a hard crop but saw the benefits of this new way of farming and morale was definitely better.’