De-lousing machines pulling in customers

Frode Håkon Kjølås of Seaside/Optimar Stette says they now have sold and produced 15 Optilice lines, all of which are in operation under industrial conditions.

And demand is so great that when the order book is finished there will be twice as many in use.

“There is a good distribution of sales in Norway and abroad,” says Kjølås, who adds that the capacity of a line is 100 tonnes / hour, and that last year approximately 500,000 tonnes were de-loused using Optilice.

The challenges of the delousing machines, says Kjølås, is to find optimal solutions for handling before and after the actual delousing.

Optilice uses heated seawater to delouse the fish, which are pumped up from the sea and pushed by impellers through a vessel containing the heated water. The exposure time can be adjusted from 21 seconds and up.

All the water, both treating water and drainage, is cleaned of lice through a drum filter. The fish are lifted over a drainage grid before sliding down a chute with the return water from the pump that is piped back to the cage.

Meanwhile, the company behind another mechanical de-louser, the Hydrolicer, say that they get reports from users that fish have a lower mortality rate using their system compared with other non-chemical delousing-methods.

Gentle and effective

Hans Martin Flasnes, marketing chief for Hydrolicer Drift AS in Norway, says: “Gentle and effective treatment is our main focus. One of the challenges we saw through 2016 was the ability to pump large fish, which is limited with today's fish pumps.”

The Hydrolicer delouses in a closed water column, using pressure and a vacuum to cause lice to lose their grip on fish.

The company started work on three new pumps in the winter and will test run these this month.

“We saw last year that current fish pumps were more sensitive to speed than was indicated by the supplier. We saw tendencies of gill damage on the big fish. We have therefore placed an internal limit of 4.8kg on fish until the new pump is in place,” he says.

“We believe that this will further improve fish health and that we will hopefully be able to run the fish up to 7-8kg.”

Low mortality just as important as power

The company reported the following average effects so far: sessile lice, 80%; mobile lice, 87%; and mature lice 88%.

“Just as important as delousing effects is that we have registered very low mortality after treatment. Recent reports from our customers shows that Hydrolicer has 50-70% lower mortality rate than several other non-drug methods,” says Flasnes.

Hydrolicer delivered 52 lines during 2016, distributed in Norway, Ireland, Scotland and the Faroe Islands.

“Already this year there are 18 lines in production and commissioning, and several customers have indicated that they will come with orders,” says Flasnes.

The capacity per Hydrolicer line is 35-40 tonnes, and Hydrolicer Drift currently operates two barges with six lines each - a capacity of 200-240 tonnes per hour per barge.

“One of our barges processed 65,000 tons during the four months, while only running 12-hour days. We have also managed to treat 2,800 tonnes of fish within 18 hours, including relocation and preparation between the cages,” says Flasnes.