A salmon’s eye view of delousing
A specialist device that can be used to trace what happens to salmon as they go through mechanical delousing systems has been developed by SINTEF Ocean in Norway.
Called Sensorfisk, it is a rubber fish-shaped unit which can be put through the delousing process alongside real salmon. SINTEF researcher Eirik Svendsen says that the project aims to improve fish welfare in commercial farms.
"A key challenge in Norwegian salmon farming is pumping and movement of live fish, especially through mechanical delousing units. Existing systems require that fish be transferred to the processing units via pumps and pipes," Svendsen tells kyst.no.
He says that, as a consequence of drug resistance and increased lice numbers, this type of management is conducted more frequently than before, adding that there are indications it may lead to increased mortality through exposing the salmon to increased stress and physical injuries such as scale loss and open sores.
Welfare concerns
The researcher points out that the development of such systems has primarily focused on the treatment outcome, while fish welfare duing the operation has become a secondary concern.
"This may be due to a lack of available technology for the assessment, control and understanding of what happens in such systems, which is particularly relevant when processes are optimized in terms of power and gentleness," he adds.
Which is where Sensorfisk comes into the equation.
"The rubber fish will not slide through the system as well as salmon do, but it allows you to collect motion-related data. This can be used to estimate the path of the sensor fish through the pipeline systems for a limited time. They can also be equipped with a camera," Svendsen reflects.
[video width="854" height="480" mp4="//www.fishfarmingexpert.com/wp-content/uploads/2017/01/skamik_sensorfisk.mp4"][/video]
Above: Footage recorded by SINTEF's Sensorfisk device as it travels through a Skamik delouser. The first version is in real time, the second in slow-motion. Video: SINTEF.
The pictures can be used to detect any issues in the pipework and also provide an insight into the journey through the system.
"Future solutions may also include other types of sensors which measure, for example, parameters such as pressure, temperature, pH, and O2 associated with the estimated position. This technological approach will eventually provide an opportunity to document measured loads in systems, which the FSA requires before new technology is put into operation," he says.
How fish experience the technology is, however, a complex and interdisciplinary subject that creates the need for close cooperation between different players in R&D, veterinary services, technology and service providers, as well as the farmers, according to the researcher.
"Such cooperation could result in knowledge about how to document and optimize new technological solutions before commissioning them. SINTEF Ocean will contribute to this by providing a common technological platform for cooperation, and through research on many levels, from small-scale testing technology with fish tank for tests at full scale by including SINTEF ACE," he concludes
The other key researchers in the project are Kevin Frank, Martin Lead, Christian Schellewald and Leif Magne Sunde.
