First ‘green’ eggs off to a good start in new incubation unit

18/03/2024
Scottish Sea Farms Egg inspection, incubation unit

SCOTTISH Sea Farms has taken delivery of the first batch of ‘green’ eggs at its new £2 million incubation unit at Barcaldine Hatchery.

The eggs, which were fertilised on-site in a first for the company, are doing well so far, said Head of Freshwater Rory Conn:

“The incubation unit is designed to receive eggs immediately post-stripping, giving us greater control in the earliest days of the production cycle. We trialled two, smaller test batches in Q4 2023 ahead of receiving our first full intake of around three million green eggs either side of Christmas. These were fertilised on arrival at the new unit. We conducted a series of assessments, from evaluating the success of the fertilisation process within the first 24 hours, to checking embryonic development around the 60-day stage. Then, when the eggs reach the eyed ova stage, they will go through a further quality check to ensure only the viable ones are transferred to incubation trays in our hatcheries.


“From the results to date, we know already that the quality of water in the green egg unit has mitigated a number of the issues we had been seeing with our intakes of eyed ova.”


The eggs stay in the incubation unit, which is adjacent to the main Barcaldine Hatchery, for six weeks to five months, depending on requirements, before being moved to one of Scottish Sea Farms’ three hatcheries: Barcaldine itself, Knock on the Isle of Mull, or Girlsta in Shetland.

The new facility enables the eggs to be incubated for longer, at lower temperatures, during the most fragile stages of development.

“We have taken the temperature down to below 2°C which, research suggests, results in better outcomes for fish health later on, particularly cardiac health,’ said Conn. “And by incubating the eggs over a longer period, we can meet our year-round demand for eyed ova, ensuring security of supply.
‘From this initial batch alone, we will be able to put close to 600,000 smolts into one of our marine farms at the required time – around late August next year. Without the green egg unit, it simply wouldn’t have been possible to produce smolts from Scottish sourced ova at this time of year.”

The bespoke unit benefits from the same purity of water and state-of-the-art RAS (recirculating aquaculture system) technology as the company’s neighbouring Barcaldine Hatchery.
Water is drawn from the nearby Gleann Dubh reservoir and filtered to remove anything over 0.1 microns, keeping bacteria and viruses out.

“We’re very confident of our water quality here at Barcaldine, which has been tried and tested over time,’ said Conn. “And the new unit’s ability to maintain water flow, temperature and water quality parameters has been excellent.”


Equally impressive has been the level of engagement from colleagues at Barcaldine, said Operations Manager Mike Tresise.


“This is a part of the production process that we haven’t been involved in until now and it is a reflection of the calibre of our people that they have got to grips with it quickly and are raring to go.”

While pre-fertilised eggs will still be supplied to Barcaldine, a significant proportion of Scottish Sea Farms’ egg production will go through the green egg unit in the next egg season, which starts in Q3 2024.

The unit has a total capacity of seven million ova at any one time and, with an input of up to three batches a year, it could potentially hold 20 million eggs annually.

“The facility is delivering what we expected it to do with this first batch and I’m confident that we will be able to produce the number of eggs we need in order to meet our smolt requirements,’ said Conn.
“That in itself is an achievement in our first run in a brand new facility, doing something we’ve never done before.”

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