With the help of AI, Vattenfall’s personnel at the Stornorrforsen hydropower plant have been able to identify fish based on a large number of characteristics. They now hope to further develop the technology. The meeting between energy production and nature is rarely as clear as in the case of hydro power plants and migrating fish. On the one hand, you have the force of enormous amounts of running water that create energy for the whole of Sweden, and on the other, salmon and other fish that want to migrate both up and down rivers and need routes past the power plants.Stornorrfors is one of the largest of the 2,000 plants in the country and is located in Umeälven River, just west of Umeå in northeast Sweden. In 2010, Vattenfall installed a new fish ladder here, which would help spawning fish bypass the power plant, and a couple of years ago they took the first steps toward a fish recognition system that would make it easier for Vattenfall to monitor, categorise and analyse the fish and their movements.The purpose of the technology is to more clearly control which fish travel up and down the fish ladders that bypass the hydro power plants, and to monitor the evolution of species over a longer period of time. For example, when farmed salmon is released into Umeälven River, it is possible to use the artificial technology to see how many of them then return and also follow the wild salmon’s way to adjacent Vindelälven river.In recent years, fish recognition has developed rapidly and there are several providers of the technology. Still, there is room for improvement and changes, not least in terms of what characteristics the algorithms recognise in the salmon.Gender is a crucial, and one of the most difficult, characteristics to recognise in spawning salmon. It is especially important to track females. The more females, the more roe and fry and, in the long run, the more adult fish. Because it is extremely difficult to distinguish between females and males, especially early in the season, gender recognition at Stornorrforsen is currently done manually and visually by highly skilled staff. The Vattenfall laboratory that works with fish recognition is unique in the world in purely technical terms, but maybe even more so in the transparency of its work. Vattenfall often collaborates with universities. Not only are they good at analysing material but also at disseminating results. In addition, the website has more than 20,000 annotated images that anyone can use for creating new algorithms.