Farming: Regenerative agroforestry practices have historically been applied to land-based food systems. But In recent years, an increasing number of eco-conscious entrepreneurs and organizations are turning their attention towards coastal ecosystems, which absorb up to 20 times more CO2 per acre than forests. By mimicking the diversity of natural reefs, ocean-farming operations produce nutrient-dense foods that enhance the sea’s biosphere and deliver a proactive approach to conservation. Seaweed and shellfish (oysters, mussels, and scallops) also require zero inputs, as they grow with just sunlight alongside the nutrients and plankton already available in seawater. New studies reveal that:
- Wild, uncultivated seaweed sequesters over 100 million metric tons of carbon in the deep ocean every year – more than all other marine plants combined.
- If we covered nine percent of the world’s oceans in seaweed farms, we could draw down the equivalent of all the greenhouse gases we emit in any one year, more than 50 gigatons.
- Seaweed absorbs excess nutrients and helps shellfish grow by reducing ocean acidification. A single oyster can filter up to 50 gallons of water per day, preventing the rise of dead zones – areas where no organisms can survive.
Within the US, nonprofits like GreenWave, which was started by Bren Smith, a former commercial fisherman, are cropping up to offer hands-on training to future ocean farmers. Smith’s multi-species vertical garden has quickly become a new model for aquaculture. On each of his 20-acre sea-plots, Smith harvests up to 30 tons of kelp per year, in addition to a quarter-million oysters, mussels, and scallops – a yield that dwarfs what is grown on most land-based farms. Seafood and its byproducts serve as promising ingredients for a wide range of products, including but not limited to:
- Food supplements – According to Smith, native seaweeds “contain more vitamin C than orange juice,” as much Omega 3 fatty acids as many species of fish, as well as a host of essential minerals – e.g., iodine, zinc, and magnesium.
- Biofuels – Seaweed grows faster and is more space-efficient than other biofuel sources. An acre of kelp has the potential to yield up to 2,500 gallons of ethanol, five times the amount derived from traditional crops – e.g., corn, soy, and rapeseed.
- Animal feed – Adding certain species of seaweed to livestock feed can reduce livestock methane emissions by somewhere between 60 to 80 percent.
Ocean farming shifts the paradigm away from exploitative conventional aquaculture, which led to the percentage of fish stocks within biologically sustainable levels falling from 90 percent in 1974 to 65 percent in 2017. This offers a triple threat of environmental and economic benefits:
- We can decrease global emission by more than one billion metric tons per year by shifting our diets toward regenerative seafood
- Artificial reef structures can revitalize degraded ecosystems by generating sanctuaries for more than 150 species of aquatic life
- The model can improve coastal economies by transforming struggling fishermen into ocean farmers with diversified revenue streams
As consumers, we must support the “blue-green” economy to ensure that we produce the most ecologically sustainable food possible.
Watch: Professor Tim Flannery is an internationally acclaimed scientist and conservationist, in addition to being one of the world’s leading voices on climate change. In his recent TED Talk, Flannery focuses on the potential for seaweed to curb global warming. From his perspective, we should be using biological pathways, which only require the sun as an energy source, to help trim global greenhouse gas emissions by three percent every year for the next 80-odd years. To maximize our carbon sequestration efforts, Flannery recommends going one step further by incorporating ocean permacultures – where fish, shellfish, and seaweed are grown together. By covering less than ten percent of the world’s oceans in diverse sea-farms, we could reduce our emissions while deacidifying the oceans and cultivating enough protein to feed a population of 10 billion people.