Gøta, Faroe Islands-based Hiddenfjord is performing sea trials of a new experimental salmon cage designed by Norwegian closed-cage specialist group FiiZK.
Hiddenfjord has received two 15,000-square-meter semi-closed cages from FiiZK, which will be installed in the next few weeks. A third cage will be installed in February 2022. They are the same model recently purchased by Cermaq Canada and SinkabergHansen, according to FiiZK.
The cages incorporate a rigid floating steel pipe collar that supports an industrial PVC bag-liner, into which sea-water is pumped from below the sea lice zone. Waste food and fish feces are collected and released further out at sea, and the whole environment is continuously monitored through a sensor network, according to FiiZK.
“We are constantly looking at how we can do things better and these new trials are the result of many years of research and development work,” Hiddenfjord CEO Atli Gregersen told SeafoodSource. “Sea lice are a major challenge and one of the ways to reduce attacks is to have salmon spend less time at sea. Hiddenfjord was the first company in the world to go into large-scale land-based RAS production for salmon [smolts], and that has enabled us to put bigger and bigger smolts to sea over time.”
Since 2014, the average size of Hiddenfjord’s smolts at transfer has been 500 to 600 grams, which reduces the time they spend in sea cages from 18 months to 11 months, Gregersen said. The company is now going one step further, by putting fish in open cages at two kilograms, reducing the time they spend in sea cages to just five months. Gregersen said it is his company’s hope that the shortened cycle, together with semi-closed cages, will result in a minimization of sea lice issues.
“We cannot continue to rely on mechanical or chemical means, so we are willing to take risks with new equipment,” he said. “FiiZK’s new cages are already in use elsewhere, and I hope that the weather and waves we experience in the fjords will not prove to be too much for them.”
Simultaneously, Hiddenfjord’s is also commencing trials on the siting of five 30,000-square-meter salmon cages in a high-energy environment between two islands, where the current can be up to three meters per second.
“We have been working with oceanic engineers who have found a way to reduce current speed going through the cages by deflecting it off to either side. This will be achieved by siting fine-mesh drogue nets upstream of the cages, attached with very tough moorings,” Gregersen said. “This work is very exciting and is a world-first. We undertook a practical trial earlier this year and were very excited by the results, which showed that the current speed going through a cage could be reduced by half. We are now ready to put the cages out and expect to stock them with fish in December 2020 or January 2021, once we are 100 percent confident that the moorings are right.”
The trials come on the back of the company’s announcement in October it had reduced its carbon emissions by 94 percent by switching its salmon deliveries from air to sea freight.
Photo courtesy of FiiZK
