The world is running short of fish. Most global fisheries are at or beyond their catch limits yet the global appetite for fish is growing.
Demand, forecast to reach 232 million tonnes at current growth rates by 2030, will soon outstrip supply (which is only forecast to be 170 million tonnes by then).
It is an obviously unsustainable trajectory and one that ocean farming pioneer and owner of Thimble Island Ocean Farm in Connecticut, USA, Bren Smith has experienced first-hand.
In his early teens, Smith went out to sea and saw how industrialised fishing fleets vacuumed up fast-collapsing fish stocks. “Because of declining fish stocks I had to say goodbye to fishing for a living. I loved it but it just wasn’t sustainable,” says Smith.
Conventional aquaculture will meet some of this growing demand but fish farms have their own environmental impact, Smith saw this when he tried his hand at it. He left it behind after witnessing the environmental toll they exacted and today he regards them as the “Iowa pig farms of the ocean.”
His next venture, oyster farming, promised to be more sustainable but two successive hurricanes swamped the beds and destroyed his harvest. It was in response to these setbacks that he re-thought the whole process, suspending his oysters above the ocean bed and realising he could also grow other crops in this fashion.
The farming system that evolved from this is a new kind of aquaculture that could have the potential to unlock the economic value of untapped areas of the sea.
Smith’s pioneering idea is ‘3D’ ocean farming. Lengths of rope suspended from the surface of his 3D farms grow seaweed, mussels and scallops above the nurseries of oysters and clams in their suspended baskets.
As well as being resistant to storm damage, the system also allows for different species of plants and shellfish to grow to suit the conditions, making it resilient to different and changing environments.
Not only are they nutritious, rich in minerals vitamins and protein, these twin harvests of sea vegetables and molluscs provide totally sustainable crops, says Smith. “I grow marine crops that require zero input. No fresh water, no fertilizer, no feeds and no land. That makes it the most sustainable form of food production on the planet.”
Globally, the seaweed industry is worth $6bn a year, yet Smith believes the potential of this harvest has barely been explored.
They are highly productive too. A single 3D farm can yield 30-60 tonnes annually. “The seaweed is the game changer for me as a farmer because it’s one of the fastest growing plants on earth, specifically our kelp. Seaweed can be the cheapest food on the planet.”
The environmental benefits are also great. Smith’s system creates artificial ‘reefs’ in which fish thrive and also captures carbon, a contributor not only to global warming but also to the acidification of the oceans. “Our farms soak up five times more carbon than land based plants.”
The system also filters out nitrogen which causes algae to grow faster than ecosystems can handle, starving fish and other aquatic life of the oxygen they need to survive. “It’s a huge problem around the globe, causing ocean dead zones,” says Smith
It is a system that shows great commercial promise. Globally, the seaweed industry is worth $6bn a year, yet Smith believes the potential of this harvest has barely been explored.
“Kelp is just the beginning of creating an entirely different cuisine. There are 10,000 edible plants in the ocean and a couple of hundred different types of shellfish. Imagine being a chef and finding tomatoes, corns, spices that you have never cooked with before and you have never eaten before.”
Smith is busy exploring these possibilities himself and with chefs, creating new sea-vegetable lines. “Kelp is like the soy of sea. We do kelp jerky, soups, ice-creams, noodles,” says Smith.
Seaweed also has use as a biofuel, for fish feed, nutrition-rich fertiliser and feedstock for the pharma and cosmetics sectors.
The 3D farm he has already established is only the beginning. Smith has set up Green Wave, a non-profit organisation designed to help train fishermen to adopt the system, giving them sustainable work with a relatively low outlay. Adopted by many at a small scale, he hopes it will make a big difference globally.
“We designed it so that there isn’t much infrastructure. That makes it extremely cheap to build. Anybody with 20 acres, a boat and about twenty thousand dollars can be farming the first year.”
“We can really scale this. If you were to take a network of our farms around the size of Washington State, you can technically feed the world. A small-scale thing can really add up to have a huge impact on our food system. And that’s important because the problems we are facing in the oceans and on land are pretty daunting.”
“What I am doing is trying to take all the lessons learned from industrial agriculture and not make those mistakes again. Our oceans are essentially a blank slate and it is up to us to build an ocean agricultural system from the bottom up, to actually do food right and grow food the right way.”Find out more on lombardodier.com