Integrated multi-trophic aquaculture is like an underwater garden. It involves growing different types of sea creatures - or "crops" - together in the same space so that each one can benefit from the others. For example, you might grow seaweed and mussels together on the same long ropes tied to buoys. The seaweed provides food and protection to the mussels, while the mussels keep the seaweed clean by filtering out small particles that get stuck to it. It's like a mini-ecosystem - each creature helps the others thrive!