The Earth will be home to nearly 10 billion people by 2050, and we need to figure out a sustainable way to feed them all.

One solution could be fish farming. Seafood is already responsible for 17 percent of the world's protein intake, and aquaculture is the fastest growing food supply sector in the world.

RAZOR's Reya El-Salahi travels to the Arctic Circle, in Norway, where the company Salten Smolt is farming salmon on land while recycling up to 90 percent of its water. It uses a technology called Recirculating Aquaculture Systems (RAS), which is also being tested by Nord University on warm water fish like tilapia. 

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Salten Smolt says the future of sustainable fish farming is both in tanks on land and technologically-advanced open water pens.

Meanwhile on the island of Indre Haroya, the company Salmon Evolution is growing fish in tanks until harvest, using a Hybrid Flow-Through System (HFS) that recycles up to 65 percent of the seawater it takes from the ocean. Salmon Evolution says that's a sweet spot that balances both sustainability and costs.