Technology
BY VINCE MCDONAGH
Face value
Machines are learning to identify individual fish out of thousands
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f you believe all salmon have the same facial expression, then it could be �me to think again, according to new research. A recent study by SINTEF, one of Europe’s largest independent research organisa�ons, and the Norwegian University of Science and Technology (NTNU), suggests it is possible to dis�nguish one face from another. They are basing their results on ar�ficial intelligence (AI) technology which has helped them carry out much of the work. By adap�ng the type of exis�ng AI technology that recognises human faces, the researchers believe they can learn more about farmed fish and how they feel at a par�cular �me. Picking out 100 random salmon from a cage that contained more than 100,000 individuals, the iden�fica�on success rate was just over 96, which is extremely high. NTNU research fellow and SINTEF researcher Bjørn Magnus Mathisen says it is difficult to explain why the technology has been so accurate, but he has been working with machine learning and ar�ficial intelligence for 10 years and it seems to work.
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He said: “We are not sure how they actually recognise the salmon, but we have a theory it is through the pigment spots on the face. They have a dis�nc�ve pigment, in the same way as with the cheetah or giraffe.” One of the things Mathisen found par�cularly interesting about the research is whether they can iden�fy the same salmon throughout their life cycle. He said: “I am really looking forward to tes�ng if this works on smolts and see if the machine is able to recognize the fish as it gets bigger. What adds a li�le to the mystery is that machines can also see things that humans do not, he suggests. In order to study the images of salmon taken by underwater cameras Mathisen uses a type of machine called a deep neural network which is modelled on the way cells in the brain are organised. A SINTEF report on his work says these neural networks are able to iden�fy animals, people and objects through sound and images in a way that was previously difficult to do mathema�cally. SINTEF says: “You cannot tell a machine how to see the difference in each fish. Like us humans, it must learn by itself. Mathisen adds: “Methodologically, machines learn a bit in the same way as humans. We learn by seeing differences.” The research is also being supported by SINTEF’s aquaculture innova�on centre, SFI Exposed, and was started as a master’s project by Espen Meidell and Edvard Schreiner Sjøblom, supervised by Kers�n Bach, Håkon Måløy and Mathisen. To train the so�ware to iden�fy fish,
Above: Bjorn Mathisen Left: A Sco�sh salmon Top right: Salmon underwater
www.fishfarmermagazine.com
10/05/2021 15:19:38
