Early on a freezing Sunday morning in December, Krista Rosen and Inga Potter of Cold Current Kelp venture out in a tiny vessel to plant new sugar kelp seedlings. Along for the ride are Gunnar Ek, an ocean farmer, and Michael Chambers, a biologist at the University of New Hampshire, who will assist with seeding the tiny baby kelp on long, rough ropes that drop into the icy waters.
The ropes will be suspended from buoys and anchored on the seafloor. The baby kelp is nearly microscopic - the shoots look like flecks of dirt on the hand. By April, in just five to six months, these seedlings will have grown up to ten feet long, and will be ready to harvest.
In recent years, the global kelp farming market has exploded; the global commercial seaweed market is projected to surpass $85 billion by 2026. Right now, roughly 90% of the seaweed sold in U.S. stores is farmed in Asia, but that could one day change as the U.S. industry rapidly grows.
This past season, over half of America’s seaweed was grown in Maine. In the last five years, kelp production in Maine has grown by 56 percent. Kelp aquaculture in other New England states is still in the early stages, but business is also growing rapidly in places like Cape Cod, coastal New Hampshire, Connecticut and Rhode Island.
Fishermen, and others who make their living on the water, are increasingly turning to kelp farming as a way to supplement their income, as warming waters threaten fisheries like lobster. In theory, a fisherman could lobster all summer and grow kelp in the winter, using much of the same equipment and the same working waterfront infrastructure.
Potter and Rosen have been growing kelp since 2022, and use the large brown seaweed to create kelp-based skin care products. They chose kelp, they say, because they wanted to be a part of the solution kelp poses when it comes to climate and environmental issues. Kelp filters excess nutrients, like nitrogen, out of the water, and it draws down and stores carbon from the atmosphere. It’s a clean crop that doesn’t require any pesticides or fertilizer, and it grows rapidly in just one season.
This season, Potter and Rosen are experimenting with mycelium-based buoys. Traditional styrofoam-based buoys can break down over time, releasing microplastics into the water. This will be the first time the team tries these mushroom buoys.
When harvested, kelp is highly perishable, which creates challenges for those growing it as a food crop. But there are many other uses for kelp, from beer to fertilizer. One Maine startup is working out a method to create a soft kelp-based bioplastic.
“The more you learn about kelp, the more exciting it is,” said Potter.
