Glimmering brown under the surface of the water, kelp and kelp aquaculture could be the future of the industry and feeding the growing human population. Algae is an extractive species, meaning that there are no nutritional inputs that a farmer has to provide for the species to thrive. Aquatic plants get everything they need from the seawater they are being grown in and sunlight. Kelp and other macroalgaes can be used in cuisine for human consumption, animal feed, biofuel, fertilizers, and other products. And it turns out that while kelps and macroalgaes are growing and absorbing nutrients, they are also absorbing dissolved carbon dioxide. Feeding the world and battling ocean acidification? Sounds like a home run.
Kelp is an aquatic plant group that has been recently used in 3D ocean farming. This is where kelp and other marine aquaculture species are grown in a scaffolding system of ropes and buoys that can be raised or lowered. This technique, pioneered by Bren Smith, helps with battling changes in tides during storms, as well as increasing ease of harvest. Smith’s 3D ocean farm currently produces sugar kelp, oysters, mussels, and scallops in the Thimble Islands of Long Island Sound. Using the entire water column to culture these species, the lease space is maximized and can produce large quantities of marketable goods. Smith’s 3D ocean farming model has been the blueprint for sustainable macroalgae and bivalve culture in the United States. What’s even more astounding is that Smith’s farm absorbs five times the amount of carbon than land-based plants do, serves as a storm surge protector for local communities, and even acts as an artificial reef habitat.
Recently, scientists from the USC Wrigley Institute for Environmental Studies have designed and implemented a similar 3D model to Smith’s. They have successfully created what they are calling a “kelp elevator” that can raise and lower the kelp to differing depths. This team is hoping to use kelps as a biofuel, much like soybeans and corn. Traditionally soybeans and corn require a large amount of land to be grown, while also needing to use pesticides and fertilizers. Since kelp only needs the ocean, there is no need for fertilizers or pesticides. All that is necessary is a minimal underwater footprint and someone to tend to the crop. This team created this kelp elevator and decided to cultivate the giant kelp, which is native to California and also has an incredibly fast growth rate and a well understood life cycle. Raising and lowering this kelp on a structure made of fiberglass tubes and stainless-steel cables, the kelp is able to absorb sunlight during the day when it is higher up in the water column and nutrients when it is lower in the water column. It would seem that 3D ocean farming is paving the way for not only food production, but also for biofuel production.
Before you go turning your nose up at the thought of eating kelp, keep in mind that every food or cuisine was new at some point in time. Kelp pasta, kelp martinis, kelp ice creams, and even kelp salads are popping up on menus all over the country. So, the next time you’re at a restaurant and you see a kelp item on the menu, give it a try. The worst thing that could happen is supporting a local kelp farmer, but the best is finding an exciting new food option that’s sustainable and healthy.