What is Ultrasonic Antifouling?
Ultrasonic antifouling is a technology that use high frequency acoustic vibrations to prevent marine growth on underwater structures.
Scientific studies have shown that when surfaces are set into vibration by high- intensity ultrasound it can disrupt the cells of algae and prevent settlement of other marine organisms. Submerged structures are equipped with ultrasonic transducers that are placed in direct contact with the material surface. The effect is strongest on materials with low acoustic attenuation, like steel or other metals. Ultrasonic antifouling works without any use of chemicals and is environmentally friendly, with no indication of negative effects on non-target species such as fish, plants and other aquatic life.
A major challenge and cost driver today in aquaculture is the control of biofouling, which is the accumulation and growth of marine organisms on submerged surfaces. Not only cage nets, but also other submerged surfaces, such as the feed barge and cage structures, need to be cleaned regularly. Growth of organisms on net cages can lead to reduced solidity of the net and can negatively affect fish growth, health and welfare [1-2]. Current biofouling maintenance includes underwater high pressure cleaning of the nets, which is a costly and time-consuming task. Control of biofouling is estimated to cost 5-10% of aquaculture production costs, which is equivalent to $1.5-3 billion per year (2012 estimate) . In addition, limited cleaning of rigid structures poses a risk for worsening of biofouling rates . The environmental concern about chemical copper based anti-fouling technology (copper based paint and copper based protection of nets) is also increasing. A recent report indicates acute poisonous levels of copper for sea animals present under fish-farming facilities , posing a clear environmental threat.
InPhase Solution has developed an Ultrasonic Antifouling System for use on submerged structures.
The system can be tailored to each submerged structure, and consists of the following standard components:
- Submerged transducers, bonded at the inside or outside of the structure.
- Transducers positioned every 5 to 7 meter.
- Transducer dimensions are smaller than 10x10x10 cm.
- Peak acoustic output power up to 50 Watts per transducer.
- Generators that can excite up to 20 transducers simultaneously.
- Distance between generator and transducers can be 50 meter.
- The system can be scaled with the size of the underwater structure.
The ultrasonic antifouling system is particularly well-suited to protect marine structures such as:
- Fish farming facilities
- Oil & gas installations
- Subsea equipment
- Offshore wind farms
- Fitridge, I., Dempster, T., Guenther, J., and De Nys, R.. "The impact and control of biofouling in marine aquaculture: a review." Biofouling 28, no. 7 (2012): 649-669.
- Braithwaite, Richard A., Maria C. Cadavid Carrascosa, and Lesley A. McEvoy. "Biofouling of salmon cage netting and the efficacy of a typical copper-based antifoulant." Aquaculture 262, no. 2 (2007): 219-226.
- Bloecher, Nina, Oliver Floerl, and Leif Magne Sunde. "Amplified recruitment pressure of biofouling organisms in commercial salmon farms: potential causes and implications for farm management." Biofouling 31, no. 2 (2015): 163-172.
- Giftig mengde kobber under flere oppdrettsanlegg, Dagens Næringsliv, 23-09-2016.