Fish farms are notorious polluters. But at the same time, as wild populations are under pressure, aquaculture remains a key hope for sustainably feeding the world.
One of the main issues impacting sea-based farms is that, in order to shelter from bad weather, they are often located near shore. This means currents are weaker and polluting particles and parasites congregate.
One solution is a new generation of cages which can survive rough weather and be deployed further out to sea.
Another approach is to rear fish on land. Again, technology can help ensure the process has as little impact on the environment as possible.