Growing Ideas: Sound waves as alternative to chemicals

Water that is set in motion by sound waves remains much cleaner. The technique reduces the mortality rate in fish farms and is better for the environment.

Nina Hanssen relocated from Norway to the Netherlands 18 years ago. Salmon farming is an important industry in Norway, where chemicals are predominantly used to get rid of parasites. One day, Hanssen found out about a Dutch technique that used sound waves to get rid of algae and barnacles and thought, “That should work in salmon farming, too.”

She now calls it her Eureka moment. She made some calls and discovered that the technique was already being used on a small scale in the breeding of koi carp. Working with its inventor, she set out to make it suitable for salmon farming. She subsequently founded the company H2O Technics together with her husband and his sons.

What does H2O Technics do?

“H2O Technics has developed a technology that uses sound waves to set water in motion. This keeps the water free of such things as parasites, algae and bacteria. Through our subsidiary company Aqua Farming Solutions, we are deploying this technique in the fish farming industry. The technique is suitable for the farming of all fish larger than five centimeters, such as salmon, cod, eel, and tilapia. It can also be used to tackle other problems. For example, sound waves can prevent mold in aquaponics, the cultivation of plants in water.”

What other problems does your company resolve?

“Salmon farming usually takes place in a cage surrounded by a fish net. Some 150,000 fish can live in such a cage. Companies often use chemicals such as hydrogen peroxide to combat parasites, but this is damaging to both the environment and the fish themselves.

“Another problem is that the salmon suffer from lice. The lice can be removed by a machine that brushes the skin of the salmon, but this damages the mucus coating of the fish, which weakens their immune system. As a result, one in five farmed salmon died in 2017 during production.

“Our technology prevents the production of parasites. While we cannot eliminate adult salmon lice, we can ensure that the eggs are no longer viable. Stopping the lice from reproducing is the most important thing according to biologists, because salmon lice can end up on wild salmon, who do not get treatment. So if we do nothing to stop the lice, salmon will become extinct.

“The sound waves also prevent the growth of algae, barnacles and seaweed on the nets. Currently robots brush the nets, with the mess ending up amid the fish. Our technique keeps up to 95% of the parasites away, which means that the nets do not need to be brushed as often.”

“If we do nothing to stop the lice, salmon will become extinct”

- Nina Hanssen, H2O Technics

What is the biggest challenge?

“The world population is growing, which means that more people will need to be fed. Fish farming is thus becoming increasingly important, but it must be done in a manner that is sustainable for the fish and for the environment. Throwing chemicals into the sea is not a good idea. The industry is ready and willing to consider alternative solutions; the young generation in particular wants to do things differently. The older generation still thinks: why change something that works? We need time to make the industry aware of our technology and to convince them that it works.”

What innovations are you currently working on?

“We are developing a ‘Legionella killer’ using the same technology but with a number of adaptations. This can be used in the water pipelines of hotels, hospitals and amusement parks to prevent Legionella bacteria. We are still developing the technique, but hope to have it ready by this autumn at the latest. We are also looking into whether we can also make the technique suitable and affordable for ordinary households.”

This interview is part of the Growing Ideas series, in which we take a look at the future of agrifood and offer a platform to innovative companies in the sector. It previously appeared in Dutch on RTLZ, the website of a Dutch business and financial news channel.