we can then reap the harvest. It has worked on land, pretty well, for feeding us for the last 10,000 years or so. In terrestrial agriculture terminology, this is called ‘agronomy’. Unlike ag on land, offshore seaweed farming doesn’t need forests to be cleared, and needs neither fresh water, nor (possibly) exogenous nutrients, yet it literally sucks CO2 out of the sea for us to use or sequester as we see fit. Marine agronomy - the culture of marine plants and macroalgae (seaweeds) to produce the food, feeds and fuels that we crave – may then be a balm to counter the coming cataclysm of ocean acidification. OK, outside of your local sushi bar, and Japan/Korea/China, seaweed isn’t much craved, but that’s just a matter of taste, and tradition. “Sit there and eat your seaweed salad, Johnny, or you won’t get any seaweed icecream!” said no-one’s Mother, ever, as she sipped on her kelp beer. Well, not yet, anyway … but people laughed at vegetarians, once. Seaweeds could also be used directly as feeds for marine fish (many great-tasting coral reef fish are herbivores) or cattle (Asparagopsis has been shown to reduce the methane in cow burps by up to 70%). Alternatively, seaweeds could be used as feedstock for producing single-celled proteins (SCPs), which could then become protein powder for body-builders, or feedstuffs for ‘carnivorous’ fish
(or for chickens, if you must). And the biodigestors producing the SCPs could be readily adapted to produce methane, or other biofuels, so we can leave more of the ancient other stuff in the ground. This is not just your crack-pot correspondent talking. Conservation International, The Nature Conservancy, and World Wildlife Fund are all working on seaweed projects with localized nutrient removal, and mitigation of acidification, as key elements. However (and you knew I was going to get to this!) to truly scale this, we need
to take it offshore. The U.S. Department of Energy seems to agree. Their Advanced Research Projects Agency – Energy (ARPA-E) just completed selection for Phase II awards for their MARINER Program (Macroalgae Research Inspiring Novel Energy Resources), with the long-term goal of developing culture systems for macroalgae for biofuels on offshore arrays, to allow production on the scale that is truly needed to make an impact on global energy demands. There is also the tantalizing possibility of using macroalgae as a carbon
I believe that the only viable option is to find some means for harnessing entrepreneurial incentives to the ecological imperative, and have businesses solve ocean acidification for us. We need to find a profitable, scalable way to remove CO2 from the oceans. Seeded ulva lines for offshore.
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