A Shellfish Manifesto for Sequestering Atmospheric Carbon in Quantity

Abstract

Mini-ReviewAtmospheric CO 2 is sequestered within shellfish shells as an indigestible, crystalline and chemically stable mix of calcium and calcium-magnesium carbonates; when the animal dies the shell remains for geological periods of time. Effectively, the CO 2 is permanently removed from the atmosphere. That's the animal's generous legacy and our inheritance. It is the certainty and permanence of the removal of CO 2 from the atmosphere that makes biotechnology using calcifying organisms so attractive as a means to ameliorate climate change. The shellfish cultivation industry is the only industry on the planet that can expand without damaging the atmosphere, we want shellfish producers to greatly expand their production specifically to generate more shell. The crucial first step is to reverse, with absolute scientific and logical confidence, today's general acceptance of the misconception that "calcification releases CO 2 into the atmosphere". This stridently maintained, but mistaken, interpretation ignores biological chemistry (which is controlled by the organism) in favour of open water chemistry (which is imposed on the organism) and directs humanity's attention away from the only ecosystem on this planet that possesses the physiological capability to remove permanently the excess CO 2 from our atmosphere. Anyone who has ever enjoyed a meal of shellfish knows from personal experience that, at the conclusion of the meal, diners are left with a bowl of discarded shells.Consequently, it doesn't matter which version of the marine chemistry mantra you believe ("calcification is /OR/ is not a CO 2 -releasing process"), it doesn't matter that the shellfish spend their lives "exhaling" respiratory CO 2 (we all do that!), it doesn't matter that the boats burn diesel fuel to CO 2 day in-day out, or that shore facilities are not carbon neutral (most, if not all, currently-operating marine facilities are like that). It doesn't matter because the fact is that our consumption of every ton of freshly harvested shellfish leaves behind (on average) half a ton of freshly precipitated limestone in the shells. Most importantly, the shell material is 95% inorganic calcium carbonate which remains sequestered for millions of years (unless someone treats the shells as "food waste" fit only for incineration). There are two other steps we must take. CHANGE the present-day paradigm of aquaculture, which is to cultivate shellfish for food, to cultivating shellfish for their shells (treating the food as a by-product). This change of paradigm places the value of the cultivation exercise on the production of shell and its removal of carbon from the atmosphere. This allows us to take the monetary value of the food that results as a by-product, so that, effectively, the food value is the earned interest on the capital invested in the shell-cultivation exercise.