Multi-trophic Aquaculture: Why is it Good to Raise Finfish, Shellfish, and Seaweed Together?

Let's talk about the circle of life—under the sea!

You see everything in nature is interconnected, nothing lives in isolation, and all living creatures are dependent on each other. In fact, very often different animals and plants live side by side, as neighbors, benefitting from each other’s daily lives. These unusual friendships are called symbiosis.

Together with marine scientists, we spent a lot of time studying how to improve the health of the seas, the fish, and all marine creatures. This led us to explore the benefits of growing fish, shellfish, and marine plants together—an idea that is known as integrated multi-trophic aquaculture (it can certainly be a mouthful, so a common abbreviation is IMTA). In kid-friendly language, it means diverse neighborhoods of marine creatures that live happily together in harmony

IMTA is an idea that we love so much because it honors and follows the rhythms of nature. In particular, it highlights how a food chain works, in which one species finds a feeding opportunity in the waste generated by another species—so one species' trash is another species's treasure!

That’s how we discovered that building an underwater neighborhood for salmon, seaweed, and mussels benefits all three. More specifically, the waste from the salmon cages are extracted by the mussels, and the seaweed absorbs the dissolved inorganic waste. The dissolved nutrients from fish waste provide valuable nutrition for the growth of the seaweed, which can have an important role in ocean acidification and sequestering carbon. Ultimately, this circle of food and waste works like a natural “recycling” system that takes care of the marine environment and the whole ocean floor.

What a beautiful win-win-win for the seas and the fish, the planet, and people!