Aqua Robotics enables safer and healthier fish farms with autonomous net cleaning

In fish farms, the nets must be kept clean to prevent build-up of algae and other organic material, known as biofouling. Biofouling limits the flow of oxygen through the cage, and is a cause of parasites, disease and also death of farmed fish.

Traditionally, fish farmers deal with biofouling by coating the nets with a paint containing copper oxide. Copper reduces the growth of organic material on the net but causes copper pollution in the local ecosystem.

Then the nets are mechanically cleaned using high-pressure underwater washing systems. This is a stressful experience for the fish, leading to reduced appetite, and it can damage the nets, increasing the risk of escapes. Furthermore, it requires a heavy, specialised, diesel-driven vessel that releases significant CO₂ emissions.

Aqua Robotics has developed the HALO-Robot, a battery-driven autonomous net maintenance system that prevents biofouling.

It consists of an operating unit that moves horizontally around the top of the cage. An attached cleaning brush system moves gently up and down the net, reaching all the way to the bottom of the cage. The brush system cleans both the inside and the outside of the net from the inside of the cage. The HALO-Robot operates continuously, and the process is entirely autonomous, including battery charging.

The HALO-Robot is delivered as an integrated system, including the technology, software, service and maintenance.

The HALO-Robot causes no stress or reduced appetite in the fish, does not damage the net, and requires minimal attention from fish farm personnel to operate. The system ensures that the net always is clean, so there is no fouling or debris released into the water mass.

Additionally, it is clean and energy efficient, using 98 per cent less energy than mechanical net cleaning. This can give annual emissions reduction of approximately 30 metric tons of CO₂ from a single pen.

Furthermore, no copper paint is washed off and released into the local marine environment.

The HALO-Robot is delivered as a pay-per-service product. In terms of cost, it is comparable to conventional cleaning methods, with the additional benefits of reduced pollution and improved fish health. This in turn improves the quality of the fish and the customer’s financial bottom line.

By 2050, approximately 40 per cent of protein consumed worldwide will come from the sea, with aquaculture production already exceeding capture fisheries in volume. The demand for solutions that increase production efficiency at fish farms while reducing environmental impact is therefore expected to grow significantly in the years to come.

The HALO-Robot from Aqua Robotics is already in operation at several of Norway’s largest fish farms.