Ocean farmers use a ruler to check how much the seaweed has grown.

Smith’s New Farm

The scientist suggested that Smith try growing a seaweed called sugar kelp. Smith was sold. He would become an ocean farmer. He would work on the ocean and feed people too!


But Smith wasn’t satisfied with growing only kelp. He wanted to produce a variety of food. How much could he produce on the 40‑acres that he rented in Long Island Sound?

sugar kelp

There was a lot to consider. How do you grow kelp? What other kinds of food crops can be raised along with kelp? How should everything be set up in a small ocean plot? And, how can the farm be run to help the ocean and not harm it?


Smith came up with a method called 3D ocean farming. Let’s see how it works.

Explore 3D ocean farming.

3D Ocean Farming

Take a look at this 3D ocean farm. You can see the purpose of those black buoys. They hold up ropes that form an underwater framework. The ropes support kelp that grows down in long ribbons. Scallops and mussels grow in nets that hang between the kelp. Below it all, oysters grow in cages on the seafloor.

Ropes are suspended 2.4 meters (8 feet) underwater.

Kelp grows fast. It’s no longer than the width of a coin when planted in December. By spring harvest, it’s 5.4 meters (18 feet) long.

Anchors keep the buoys and ropes in place.

How Do They Start?

Crops on land begin as seeds planted in the ground. How do kelp, mussels, and other ocean farm “crops” get their start? It depends.


For kelp, the farmer collects some kelp each fall and brings it to a nursery. There the kelp produce tiny round spores. The spores are attached to a string that is then rolled around a tube. The seeds continue grow on the string until harvest.


It’s different with mussels. Young mussels called larvae swim in the ocean. They attach themselves to parts of the kelp. There the larvae grow small, hard shells. The farmer removes these baby mussels and loads them into mussel socks. They poke through the mesh as they grow.

Kelp spores grow around a tube in a nursery.

Other shellfish usually start out life in a nursery before being moved to the 3D farm to continue growing.