During delousing, the fish are tightly gathered in a net and then pumped into the delousing system. In this process, as with all fish treatments, maintaining a sufficiently high and stable oxygen level in the water is a critical factor for fish welfare. Traditional methods of oxygenation typically don’t sustain enough oxygen in the water for the fish to be able to use it and they often require large amounts of energy and oxygen.
Beitveit Holding saw incredible results using Moleaer’s nanobubble technology to apply ample and stable oxygen to their fish during delousing treatment.
Together Kenneth Beitveit and his brother Ronny run the company Beitveit Holding after entering the aquaculture industry in 2020 with the newly acquired delousing vessel Sea Liberty I.
In the beginning, the company used a bank of oxygen cylinders to supply oxygen. The oxygen was then delivered through a diffuser system consisting of perforated hoses that were supposed to introduce oxygen into the water.
However, the diffuser system required large amounts of oxygen.
"We had to constantly replace the oxygen cylinder banks. It became expensive, and there was a lot of logistics involved in filling oxygen cylinders," says Beitveit.
As a result, the company ordered two large oxygen generators, one for Sea Liberty I and one for the company's new delousing vessel, Sea Admiral, which started operations in 2023. This reduced logistics, and the generators provided a stable supply of oxygen, however, the generators only solved part of the problem.
"The generators delivered plenty of oxygen. The problem was that the fish couldn't utilize it," says Beitveit.
"The diffuser hoses delivered a fountain of bubbles into the sea, but the oxygen bubbles rose quickly, broke the surface and were lost to the atmosphere."
Together with customers, Beitveit Holding decided to test Moleaer’s nanobubble technology. Two Trinity nanobubble generators were installed on the vessels in early 2023. The nanobubble generators were integrated into the existing oxygen distribution system, producing nano-sized bubbles of oxygen and efficiently dissolving oxygen into the water. Unlike the system with diffuser hoses, nanobubbles do not rise but remain in the water. Kenneth Beitveit noticed a significant difference.
"It worked like a charm. The oxygen meters gave good values with the old system as well, but only where the diffuser hoses released bubbles, and only as long as the system was running. As soon as we turned it off, the values dropped. With nanobubbles, we got a completely different dispersion and stability in the water," says Beitveit.
Nanobubbles are around 100 nanometers in diameter, 2500 times smaller than a grain of salt. The size gives the bubbles properties that prevent them from rising to the surface but instead spread in the water.
Research conducted in 2017 at UCLA (University of California) showed that with Moleaer's nanobubble technology, 86% of the supplied oxygen was dissolved in the water, while traditional diffuser systems only achieved 28%.
Another advantage of nanobubble technology is that not all oxygen bubbles are immediately dissolved in the water. Research has shown that nanobubbles can stay in the water for several weeks without rising to the surface or collapsing. Thus, the bubbles act as a buffer to maintain oxygen levels in the water over time.
Nanobubbles ensure stable oxygen saturation during fish treatments, such as delousing, transport, or in connection with waiting pens before processing.
But the technology is also very useful for maintaining oxygen levels throughout the pen, for example, during seasonal variations and sudden drops in oxygen saturation. Nanobubble technology has also proven effective in maintaining a stable oxygen level in land-based facilities. The result is improved fish welfare and better production in the facility.
For Beitveit Holding, the efficiency of nanobubbles is also reflected in operating costs.
With less workload on the generators, they also draw less power from the vessels. And that, in turn, means less expenses for diesel.
When Beitveit sees how much less oxygen is needed with nanobubble technology, he has come to the conclusion that he might as well have skipped investing in two massive oxygen generators.
“We can kick ourselves now for buying the oxygen generators, but we didn't know any better. If it were today, we would never have ordered them. Nanobubble technology is here to stay. If we will have more delousing vessels in the company, it will be oxygen cylinders and not oxygen generators on board.”
Service of Moleaer’s nanobubble generators has also be easier, with only 10 minute clean-in-place every 14 days.
The transition also results in saved costs for service and handling of diffuser hoses.
"We know from one of our customers, who used the diffuser hose system for ten years, that it had an annual service cost of 70-120,000 NOK. We now avoid that. Now, it's just regular air hoses we lay out. We still don't know the service interval on them, but it's a much simpler system.
And when it comes to work and handling, it's like night and day. With the new system, there is no handling at all; it's incomparable.
Their customers are absolutely delighted.
“I don't think our customers will want anything else now, seeing the results. They see that nanobubbles provide a nice dispersion to the water, and it works like a charm. This is here to stay,” says Beitveit.
Beitveit has no doubt that nanobubble technology is by far the best system for supplementing oxygen to the water during fish crowding operations. The only thing he wishes is that he knew about the technology sooner.
“This is the best innovation for oxygen supplementation on the market. There are no other systems that come close.”