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Optoscale weighs up significance of Innovation Award

Rob Fletcher
Rob Fletcher
02 August 2017, at 3:05pm

A novel system to measure the weight of salmon in cages without disturbing them is one of the three technological developments to be shortlisted for this year’s Aqua Nor Innovation Award.

Accurately measuring the total biomass of salmon, or their average weight, in a cage can improve husbandry practices. OptoScale, based in Trondheim, has been nominated for the award for a system that uses laser lights and advanced algorithms to improve these estimates – an advance that can help improve the profitability and sustainability of the aquaculture operation.

Unlike some of the other systems available, OptoScale can distinguish individual fish from the population in the cage. Like many others working with biomass measurement, the system uses a stereo camera – ie two cameras that have slightly different fields of view. By having two slightly different pictures of the fish, one gets a better depth of vision and of the circumference of the fish. 

In addition, OptoScale uses a laser beam which is sent out in a striped pattern, rather than the traditional LED light. This gives much more information than when using the traditional lighting, since the curves of the light stripes change with the fish’s circumference. In addition, the stripes will change even more if they hit a fish that is in front of or behind the fish that is being measured – in this way the system is able to separate out individual fish from the population in the cage.

Sven Kolstø, co-founder and CEO of OptoScale, points out that precision in biomass measuring has great advantages.

“Traditionally,” he observes, “biomass measurement has been important for the fish farmer in order to get the most accurate estimate of slaughter weight. Accurate slaughter weight means improved profitability – the more accurate your estimate, the better price you will get. But the advantages are more numerous if the accuracy improves.”

Kolstø claims that the advantages of accurate biomass measurement go beyond slaughter weight estimation. “Today’s technology often has a margin of error of 3 to 5 %. The fish grows at a rate of about 1 % each day. When the margin of error is larger than the growth rate of the fish, the weight data from the cage has no value beyond estimating the slaughter weight at the end of the production cycle. Our objective is to achieve only 1 % deviation by the end of the year – and with such precision the industry can use biomass measuring as a decision support from day to day.”

With daily updates of accurate figures, the fish farmer can rapidly determine if the fish weight suddenly diminishes, or increases. Thus it is possible to measure feeding volumes and regimes, noise levels, and initiatives that stress the fish against actual growth of the fish – therefore farmers can decide what they need to do more or less of. It also enables comparisons across different cages and locations.

At the same time that daily updated data is available, the fish farmer will also get more precise historical data. 

Commercial support

Kolstø emphasizes that local salmon producer SalMar has been central in the development of the system, which is now only months away from being commercialised.

“SalMar has been an outstanding partner from Day 1. We came up with the idea, called SalMar, and then a few weeks later we were working with them on their cages. They have made test facilities available to us, they make people available, boats and installations are available when we visit, and in general they are just incredibly accommodating. They are always helpful,” he says.

Kolstø says it has been his personal goal for almost two years to be nominated for this award.

“We were at Aqua Nor in 2015, only a couple of months after we started thinking about whether this was possible. There and then we decided to win the Innovation Award in 2017 and launch our product then. This award is the industry’s own stamp of quality – there is a jury that understands the problems facing the industry, existing technology and the value chain, and they select the innovation they believe in.”

Next steps 

With working prototypes in the sea and three systems in production, OptoScale has now changed the focus to work on programming and the algorithms the interpret the pictures, 3D models and present the data in the online portal.

“This now needs to be fine-tuned and by the end of 2017, our goal is to be able to estimate the weight of 1000 fish per day, compared to the 100 we measure today. And we shall also only have a 1 % deviation in our estimates,” he says.