It’s a simple problem: we lack good land to grow food, so we have to keep growing more food on less land.
Currently, half of the habitable land on Earth is devoted to agriculture. The good news (sort of) is that the land we currently use isn’t being used as well as we could be, as poor cultivation practices and pesticides deplete the soil’s precious resources.
A similar scenario is playing out in our oceans, where plastic, pollution and overfishing are putting pressure on a food source that feeds millions.
Finally, you can add the huge carbon footprint of agriculture, especially meat farming, and its contribution to climate change, which also negatively affects the ocean.
Enterprising farmers, fishermen and farmers-slash-Fishermen are turning to a solution they believe can not only help provide more food in a more sustainable way, but also help replenish and heal the oceans – a practice known as regenerative agriculture.
Farming marine plants and animals, known as ocean agriculture or “aquaculture,” can not only help us produce food, but also help fight climate change and clean up coastal waters.
Carbon-capturing kelp extracts CO2 from water and air, and water-filtering seashells can purify ocean water. Algae and shellfish are both natural filters, with oysters filtering up to 225 liters of water per day.
This means that the marine farms that grow them can actually remove excess carbon, nitrogen, and other pollutants.
Ocean farms also provide natural habitat for other forms of marine life, and human-planted kelp forests could replace lost marine habitats and bolster those that are shrinking.
Fertilizers play a crucial role in our ability to grow large amounts of food – enough for the world’s population and more. But it’s made from large amounts of natural gas, and excess nitrogen fertilizer runoff is polluting waterways. Pesticides can also run off during rains and irrigation, killing animals we never intended to kill and polluting water sources.
The plants and animals involved in ocean farming are essentially turnkey; Once the system is in place, you can let the marine life do its thing until it’s ready for harvest. Not only does this lead to a lower carbon footprint, but, more importantly, it means no fertilizers, pesticides or herbicides are needed.
These regenerative practices make aquaculture attractive not only from a production perspective, but also from a sustainability perspective.
3D ocean farming
The aquaculture facilities designed by GreenWave are precise and proven: using ropes, baskets and boxes, they cultivate algae, kelp and shellfish.
“It might sound pretty simple, and not exactly the most technologically futuristic thing,” says futurist Tom Carroll. But the way aquaculture is approached is key to its appeal.
Ocean farming has an advantage that traditional land-based farming doesn’t: you can do it in 3D, layering your produce, like a tower of seafood, to fit more in less space.
By exploiting the entire water column, aquaculture can produce up to 30 tonnes of algae and 250,000 shells per year, per acre.
Strings of seaweed, kelp and other sea vegetables are first tied near the surface, where they can suck up the sunlight needed for their rapid growth. Suspended from longlines beneath the plant life are containers filled with shellfish like mussels and scallops. And at the bottom, boxes serve as shelters for oysters and clams, waiting for crushed ice and champagne.
By using a variety of crops and creatures all growing together in harmony, aquaculture can not only maximize space and yield, but is also more resilient than many forms of land-based agriculture, where reliance on regard to a strain of a can lead to the destruction of entire fields by a single disease.
GreenWave, a non-profit organization founded by former fisherman Bren Smith, is helping foster 3D ocean farming, with the goal of getting 10,000 farmers laying lines and raising bivalves within a decade . The non-profit organization helps interested farmers set up their first farms, requiring only a boat and relatively little capital – around $20,000 to $50,000.
Importantly, GreenWave is also trying to fix one of the current weaknesses of 3D ocean farming: a market. As seafood and seaweed markets grow, farmers need to find a demand to satisfy or farms will flounder. GreenWave’s Algae Source is designed to help small to medium-sized sellers connect with buyers, although it’s currently limited to New England.
The seaweed market East growing, though – you can use it for animal feed, packaging, or to make a burger. And plants also have other uses that make them attractive tools to not only avert some damage from climate change, but also to help reverse it.
Carbon capture and biofuels
Growing up on Lake Michigan, Adam Baske always wanted to be a fisherman. But instead of scavenging carp from freezing inland seas, Baske captures carbon off the coast of Maine with Running Tide Technologies.
Algae like kelp actually remove more carbon from the atmosphere than many land plants, with its impact comparable to that of tropical rainforests, Montclair State marine biologist Colette Feehan previously told Teresa Carey from Freethink.
How much carbon kelp can capture is still unknown, although research is ongoing to find out.
Algae are also a potential source of biofuel.
The aptly named giant kelp can reach one foot a day, without the need for fresh water, fertilizer or soil, Southern Cal researchers wrote in The Conversation. This makes them both more sustainable and scalable than commonly used biofuel crops like corn, palm or soybeans.
Marine plant life can be transformed into a variety of energy sources, including ethanol and “bio-crude” (organic-derived oils that can be refined into fuel), potentially powering trucks, researchers say. , airplanes and other large vehicles that are difficult for current battery technology.
Turn to the sea
Humans have relied on the oceans for food for centuries, with the ancient Romans growing oysters in baskets – not too a far cry from the 3D aquaculture that GreenWave helps promote today.
By turning to the sea again, and not just using it but caring for it through regenerative agriculture, we may be able to keep pace with less waste and a better world.