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A biotechnological expansion of shellfish cultivation could permanently remove carbon dioxide from the atmosphere

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Moore, D. (2020). A biotechnological expansion of shellfish cultivation could permanently remove carbon dioxide from the atmosphere/Una ampliación biotecnológica del cultivo de moluscos bivalvos podría eliminar permanentemente el dióxido de carbono de la atmósfera. Mexican Journal of Biotechnology, 5: 1-10. FULL TEXT OPEN SOURCE DOWNLOAD FROM THIS URL: https://doi.org/10.29267/mxjb.2020.5.1.1. To combat climate change, proposals have been made to develop methods that would pull carbon dioxide out of Earth’s atmosphere. One recommended approach is to remove CO2 from the atmosphere with activities such as reforestation and changing forest management and agricultural practices to enhance soil carbon storage. However, it is also noted that such activities would limit land for food production and negatively affect biodiversity. Furthermore, decay of dead wood and fallen leaves in natural forests releases huge quantities of CO2 and other greenhouse gases back into the atmosphere. The only other carbon-sequestration technique that is widely considered is the application of CO2 capture processes to flue gases of power plants, which are responsible for about 80% of the worldwide CO2 emission from large stationary sources. Hydrate-based processing is a promising technology for CO2 capture as it results in high CO2 recovery, but its high cost prevents this technology having much impact. In this note I suggest that the ability of marine organisms (shellfish and coccolithophore algae) to remove permanently CO2 from the atmosphere into solid (crystalline) CaCO3 should be harnessed. I suggest that if the level of finance and effort that are readily anticipated for forest management and flue gas treatments were to be applied to expansion of shellfish cultivation around the world, significant amounts of carbon dioxide could be permanently removed from the atmosphere within the timescale that is currently envisaged for carbon capture by afforestation.
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Moore. / Mexican Journal of Biotechnology 2020, 5(1):1-10
A biotechnological expansion of shellfish cultivation could
permanently remove carbon dioxide from the atmosphere
Una ampliación biotecnológica del cultivo de moluscos bivalvos podría
eliminar permanentemente el dióxido de carbono de la atsfera
David Moore
School of Biological Sciences, Faculty of Biology, Medicine and Health, The
University of Manchester, Manchester, United Kingdom.
*Corresponding author
E-mail address: david@davidmoore.org.uk (D. Moore) (retired from the University
of Manchester).
Article history:
Received: 14 November 2019 / Received in revised form: 15 December 2019 /
Accepted: 16 December 2019 / Published online: 1 January 2020.
https://doi.org/10.29267/mxjb.2020.5.1.1
ABSTRACT
To combat climate change, proposals have been made to develop methods that
would pull carbon dioxide out of Earth’s atmosphere. One recommended approach
is to remove CO2 from the atmosphere with activities such as reforestation and
changing forest management and agricultural practices to enhance soil carbon
storage. However, it is also noted that such activities would limit land for food
production and negatively affect biodiversity. Furthermore, decay of dead wood
and fallen leaves in natural forests releases huge quantities of CO2 and other
greenhouse gases back into the atmosphere. The only other carbon-sequestration
technique that is widely considered is the application of CO2 capture processes to
flue gases of power plants, which are responsible for about 80% of the worldwide
CO2 emission from large stationary sources. Hydrate-based processing is a
promising technology for CO2 capture as it results in high CO2 recovery, but its
high cost prevents this technology having much impact. In this note I suggest that
the ability of marine organisms (shellfish and coccolithophore algae) to remove
permanently CO2 from the atmosphere into solid (crystalline) CaCO3 should be
harnessed. I suggest that if the level of finance and effort that are readily
Mexican Journal of Biotechnology 2020, 5(1):1-10
Journal homepage:www.mexjbiotechnol.com
ISSN:2448-6590
SHORT COMMUNICATION
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Moore. / Mexican Journal of Biotechnology 2020, 5(1):1-10
anticipated for forest management and flue gas treatments were to be applied to
expansion of shellfish cultivation around the world, significant amounts of carbon
dioxide could be permanently removed from the atmosphere within the timescale
that is currently envisaged for carbon capture by afforestation.
Key Words: aquaculture, atmosphere remediation, carbon capture, carbon
dioxide, shellfish, shell-CaCO3.
RESUMEN
Para combatir el cambio climático, se han hecho propuestas para desarrollar
métodos que eliminen el dióxido de carbono de la atmósfera terrestre. Un enfoque
recomendado es eliminar el CO2 de la atmósfera con actividades como la
reforestación, y el cambio en la gestión forestal y las prácticas agrícolas para
mejorar el almacenamiento de carbono del suelo. Sin embargo, esas actividades
limitarían la tierra para la producción de alimentos y afectarían negativamente a la
biodiversidad. Además, la descomposición de la madera muerta y las hojas caídas
en los bosques naturales libera enormes cantidades de CO2 y otros gases de
efecto invernadero a la atmósfera. La única otra técnica de secuestro de carbono
que es ampliamente considerada es la aplicación de procesos de captura de CO2
de los gases de combustión de las centrales eléctricas, que son responsables de
aproximadamente el 80% de la emisión mundial de CO2 de grandes fuentes
estacionarias. El proceso basado en la producción de hidrógeno con captura de
CO2 es una tecnología prometedora para la captura de CO2, ya que resulta en una
alta recuperación de éste gas, pero su alto costo evita que esta tecnología tenga
mucho impacto. En esta nota sugiero que se aproveche la capacidad de los
organismos marinos (moluscos bivalvos) para eliminar permanentemente el CO2
de la atmósfera en sólido (cristalino) CaCO3. Sugiero que, si el nivel de
financiamiento y esfuerzo que se preveé fácilmente para la gestión forestal y los
tratamientos de gases de combustión se aplicaran a la ampliación del cultivo de
moluscos bivalvos en todo el mundo, se podrían eliminar permanentemente
cantidades significativas de dióxido de carbono de la atmósfera dentro del plazo
previsto actualmente para la captura de carbono por reforestación.
Palabras clave: acuicultura, captura de carbono, CaCO3 de concha de moluscos
bivalvos, dióxido de carbono, moluscos bivalvos, remediación atmosférica.
1. INTRODUCTION
Photosynthetic carbon capture by trees is widely considered to be possibly our
most effective strategy to limit the rise of CO2 concentrations in the atmosphere,
and there are several ambitious targets to promote forest conservation,
afforestation, and restoration on a global scale.
The Intergovernmental Panel on Climate Change Special Report of 2018 (IPCC,
2018) suggested that an increase of 1 billion hectares of forest will be necessary to
limit global warming to 1.5°C by 2050. Bastin et al. (2019) mapped the global
potential tree coverage and estimated that the world’s ecosystems could support
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an additional 0.9 billion hectares of continuous forest (corresponding to more than
25% increase in forested area) and that such a change has the potential to cut the
atmospheric carbon pool by about 25%. I like trees and I am all in favour of
planting more of them, but as a mycologist I have to say that there is a negative
side to these estimations that seems to be escaping notice.
This is that forests don’t only contain trees that can store gigatonnes of carbon in
the wood they make; forests also contain wood-decaying fungi that can (and do)
digest that wood, releasing greenhouse gases, including CO2, in the process.
Chlorinated hydrocarbons also make a normal every-day contribution to the
degradation of timber. The fungal chloromethane contribution to the atmosphere
has been estimated at around 150,000 tonnes per annum (Watling & Harper,
1998), which is about 60% more than was released into the atmosphere by
industrial coal burning furnaces worldwide in the year of publication.
Of course, the ultimate end-product of digestion is CO2. On a global scale,
decomposition of seasonally shed leaves, petals, ripe fruit, and dead wood
releases billions of tons of CO2 to the atmosphere each year, a similar magnitude,
in fact, to the annual CO2 emissions from fossil fuel combustion (RinneGarmston
et al., 2019).
However, Boysen et al. (2017) note that using biomass plantations to sequester
carbon would reduce biodiversity, because they are likely to be monocultures, and
occupy land that might otherwise be used for food production. These authors
conclude: ‘…that this strategy of sequestering carbon is not a viable alternative to
aggressive emission reductions…’
Most current research on ‘aggressive emission reductions’ is focussed on the
integration of new technologies to capture CO2 from flue gasses in power plants,
which are responsible for about 80% of the worldwide CO2 emissions (Romano et
al., 2013). Methods based on exposing flue gas to water under suitable conditions
(‘hydrate-based processing’) is a promising and high efficiency technology for CO2
capture, but the high cost of maintaining suitable conditions for hydrate formation is
preventing wide industrial application of this technology (Li et al., 2019).
So, if the forests and capture from flue gases can’t save us, are we doomed? Well,
no, actually; we just need to change our focus; turn away from trees (but still plant
them; they’re good for us in so many ways) and concentrate on shellfish.
2. CARBON SEQUESTRATION POTENTIAL OF SHELLFISH
About half the mass of shellfish is shell, and shellfish-shell is solidified CO2. The
difference is, it’s permanently solidified (mineralised) CO2. Molluscan shell is a
typical biomineral composed of CaCO3 with a small amount of matrix proteins
included that direct the species-specific crystal growth; arthropod (crab, shrimp,
lobster) exoskeletons are composed largely of chitin hardened with calcium-
magnesium carbonate nanocrystals (Boßelmann et al., 2007).
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Ca2+ is absorbed through specific transporters in the tissues of the animals and is
reacted with HCO32-, which is synthesized from CO2. HCO32- is partly absorbed
directly from the surrounding water (or gaseous atmosphere for terrestrial species).
The rest derives from CO2 generated by the animal’s food through the TCA cycle.
The fractions derived from these two sources differ widely (McConnaughey &
Gillikin, 2008; Filgueira et al., 2019). Knowing when calcification draws mainly on
CO2 from food or depends on inorganic carbon from ambient air or water is a
crucial consideration for studies of nutrition, ecology, conservation and cultivation
but it is not relevant to this discussion. My only interest is mineralization of
atmospheric CO2 in the shell. For animals which are filter feeders; the CO2
generated by their TCA cycles comes from digestion of plankton and is derived
from planktonic photosynthesis (Tassanakajon et al., 2008). For terrestrial species
the source is the photosynthesis of terrestrial plants. This is true even for
predators, scavengers and detritus feeders, aquatic and terrestrial; all depend on
fixation of photosynthetic carbon from the atmosphere at the root of the food chain.
There is no other source of metabolic carbon.
Ultimately, then, the CO2 for the shell comes from the atmosphere and stays out of
the atmosphere. Intact shellfish shells are excavated regularly from the middens
associated with coastal Palaeolithic human communities (old Stone Age; from
around 12,000 years ago). Intact shellfish shells abound in deep-water cores of
ancient coastal sediments of hundreds of thousands of years ago. And remember
the fossils from deep time: brachiopods (550 million years ago), trilobites (520
million years ago) and ammonites (240 - 65 million years ago). Certainly, these
fossil shells are changed considerably in chemistry by now, but the shells survive
over geological time in order to be fossilised; and in vast numbers. How much
more permanent, do we need permanent to be?
The Food and Agriculture Organization of the United Nations Fisheries &
Aquaculture Department maintains a database of Global Aquaculture Production
that contains statistics on production volume. In this respect ‘Aquaculture’ is
understood to mean the farming of aquatic organisms including molluscs and
crustaceans. Farming implies some form of intervention in the rearing process to
enhance production, such as regular stocking, feeding, protection from predators,
etc. Farming also implies individual or corporate ownership of the stock being
cultivated. For statistical purposes aquatic organisms which are exploitable by the
public as a common property resource, with or without appropriate licences, are
the harvest of fisheries, not aquaculture.
3. APPLICATIONS OF BIOTECHNOLOGY IN SHELLFISH CULTIVATION
Data from FAO Fisheries and Aquaculture Information and Statistics Branch (as of
25 May 2019) show that over the years 2010 to 2017 aquaculture harvests across
the globe totalled 53,512,850 metric tonnes of crustaceans and 122,527,372 metric
tonnes of molluscs (a combined total of 176,040,222 metric tonnes in 8 years).
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If we assume that the shell represents 50% of the animal’s mass, then the total
shellfish-shell produced was 88 million tonnes over 8 years; which is an average of
11 million tonnes of shell per year. Filgueira et al. (2019) arrive at a similar value
for bivalve molluscs alone. I quote: “Taking into account the global annual
production of cultured bivalves is 14 x106 tons, including clams, cockles, oysters,
mussels and scallops (www.fao.org reporting 2015 data) and assuming an average
contribution of shell to total body weight of 50% (general ballpark figure given that
this varies greatly between species), shell represents a residue (potential by-
product) of 7 × 106 tons, of which 95% is calcium carbonate.”
Returning to my calculation, if we further assume that for both crustaceans and
molluscs the shell is made from CaCO3; on a molar mass basis, carbon represents
12% of the mass of calcium carbonate. So, 11 million tonnes of shell per year is
equivalent to 1.32 million tonnes of carbon per year being captured from the
atmosphere by current aquaculture activities.
Global carbon emissions from fossil fuel use were 9.795 billion tonnes in 2014 (or
35.9 billion tonnes of carbon dioxide) [https://www.co2.earth/global-co2-emissions].
So, a thousand-fold increase in aquaculture would permanently remove about 14%
of the global carbon emissions in each year.
Could that be done? Possibly. If we doubled aquaculture production of crustaceans
and molluscs each year then from the 14th year we could be removing 10.7 billion
tonnes of carbon from the atmosphere each year.
Sustained annual doubling may not be realistic; but this simple calculation
indicates that with determined effort (and adequate finance) to vastly increase
aquaculture production we could be permanently extracting significant amounts of
carbon annually from the atmosphere within the timescale that is currently
envisaged for carbon capture by vastly increased afforestation.
The carbon balance of the growth phase of the animals is not important. Nor is
harvesting, though the animals within the shells could be a valuable source of
animal protein (with the profits contributing to finance for further expansion in
cultivation). However, because our emphasis is focused on the animal as shell,
rather than the animal as food, our unharvested shellfish farms could be placed in
waters polluted with toxic wastes or toxic microbes. The most relevant fact being
that when the animal dies (either in the aquaculture farm or in your kitchen) it
leaves behind a shell made of insoluble carbonates constructed using CO2 which is
now permanently removed from the atmosphere. The same considerations apply to
crustacea, freshwater shellfish, and land snails.
4. MISSED OPPORTUNITIES
Unlike the forestry industry and its trees, the shellfish industry does not seem to
appreciate the atmosphere-positive aspects of its animals. Just a few examples will
suffice to illustrate this.
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The Shellfish Growers Climate Coalition website stresses the adverse
effects on production due to ocean acidification, increasing seawater
temperature and disruption caused by superstorms (Global Aquaculture
Alliance website). Although, of course, if enhanced shellfish cultivation
permanently sequestered a significant amount of atmospheric CO2,
acidification would also reduce.
Reduced calcification by marine algae due to ocean acidification in
response to rising atmospheric CO2 is also a concern in research on
coccolithophores (Iglesias-Rodriguez et al. 2008). The relevance of this is
that from the mid-Mesozoic Era in our geological history, coccolithophores
have been major calcium carbonate producers in the world’s oceans, today
accounting for about a third of the total marine CaCO3 production.
Although both calcification and net primary production in these species are
significantly increased by high CO2 partial pressures, the possibility that the
algae could be used to trap atmospheric CO2 does not seem to have been
recognised.
It has been suggested that seaweed aquaculture to upscale offshore kelp
forests could provide sufficient CO2 sequestration to mitigate climate change
(Froehlich et al., 2019). This could certainly provide temporary carbon
capture in the short term that would be a useful contribution, but while kelp
forests solve the ‘land-usage’ issue, they still suffer from the same
limitations as terrestrial forests. Specifically: when the plant material dies it is
digested and the CO2 it has sequestered is returned to the atmosphere. The
only permanently removed carbon would be in the crustaceans and
molluscs that would undoubtedly flourish in the seaweed forest.
The book Goods and Services of Marine Bivalves (Smaal et al., 2019) deals
with a wide range of aquaculture topics including genomics-driven
biotechnological innovations like new pharmaceuticals from molluscs,
habitat and ecosystem-engineering modification in coastal protection by
reef-building bivalves, water clarification services provided by their filter
feeding and even shells as collector’s items, but does not include a chapter
dealing specifically with the potential service of extracting carbon from the
atmosphere.
Filgueira et al. (2019) make the closest approach but they conclude that the
“0.45 g CO2 sequestered by the shell of each cultured mussel in Norway is
hardly significant taking into account that a regular car produces more than
100 g CO2 per km”. Personally, I would expect more than one mussel in a
serving; say, at least 20. So, moules marinière for two persons would
sequester about 20 g CO2; in just one meal. Feeding the rest of the family
and a few friends the same way could easily sequester that 100 g CO2 and
be much more beneficial for the atmosphere than ten meals of prime beef.
Remember, the CO2 is permanently sequestered, but you’ll be hungry again
the next day; and, presumably, so will your neighbours. Filgueira et al.
(2019) conclude “although this is far from solving a global problem,
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everything counts. In addition, it is important to re-emphasize that this
comes at no cost or effort given that bivalves are cultured to produce food.” I
am suggesting a change of focus: culture the bivalves, and those other
shellfish, to sequester permanently CO2 from the atmosphere and accept
the food as the by-product.
5. CONCLUSIONS
My suggestion would be that a realistic plan might feature three prime targets:
A. Fund a development foundation that will invest cash immediately in every
existing aquaculture enterprise with the aim of doubling their production each
season for the next three to five seasons. This is unlikely to be easy because of
perception that expansion of the shellfish industry could have negative
environmental effects on coastal waters by exceeding the population size the
environment can sustain (carrying capacity). There are also concerns about social
issues (aesthetic loss) and a supposed “loss of nature” (Newell, 2007; Newell et
al., 2019; Smaal & van Duren, 2019). Such perceived negative environmental
effects are not unique to shellfish cultivation and certainly have their parallels in
large-scale tree planting (use of scarce agricultural land, loss of biodiversity in
monocultures, as noted above).
B. Fund research programmes to study:
existing aquaculture farming methods to adapt them to wider ranges of sites
and locations (Newell et al., 2019) [imagine a mussel farm on every offshore
wind turbine, every oil and gas rig, every pier, wharf and jetty, every
breakwater or harbour wall]. Again, not easy: other people have rights,
privileges, ownerships and fears and prejudices. But then, try suggesting it
would be a good idea to plant a forest of oak trees in Trafalgar Square, the
Avenue des Champs-Élysées, or National Mall and Memorial Parks in
Washington, D.C.
New aquaculture farming methods to establish new organisms and new
methods to enhance incorporation of atmospheric carbon into shells.
C. Fund developmental research into high-technology programmes.
Biotechnological research on aquaculture is well established (e.g. Rasmussen &
Morrissey, 2007; Xiang, 2015). A more unusual suggestion would be to determine
whether we could grow coccolithophore algae in giant illuminated fermenters
(maybe using the Quorn™ fermenters as a model; see Moore et al., 2020)?
Perhaps we could harvest a sludge of insoluble plates of calcium carbonate from
which we could build our own ‘white cliffs of Dover’, because using this calcium
carbonate as a feedstock for cement production could replace the fossil limestone
that is currently used to make quicklime (in 2014, cement production accounted for
6% of the fossil CO2 emissions from industrial sources). Our way of life uses a lot
of cement.
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We need plenty of funding and the determination to do it. So, if there’s anyone out
there with the odd billion dollars to spare just let me know and I’ll get the
programme rolling … but, for the moment, would anyone like another bowl of
moules marinière; or maybe a crab salad?
CONFLICT OF INTEREST
The author has no conflicts of interest to declare.
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... We prefer to suggest as an alternative biotechnology that we employ a proven draw down process to return atmospheric carbon to the neo-fossil state. Change the focus by turning away from photosynthetic organisms (but still plant, restore and conserve them; they are significant to us in so many biological, ecological, social and cultural ways) and concentrate on marine calcifiers for really long-term carbon sequestration (Moore, 2020;Moore, 2021;Moore et al., 2022a). ...
... We know that some marine scientists are unconvinced that shell biomineralisation is effective in carbon sequestration, but we believe that the simplified biology indicated here (and further discussed by Moore, 2020, Moore, 2021Moore et al., 2021a andMoore et al., 2021b; demonstrate that the scientific evidence shows it is an effective carbon sink providing overall CO 2 budgets in biologically natural conditions are considered, rather than individual reactions in open water conditions. This is demonstrated in the most recent life cycle assessments (LCA) of mussel, oyster and clam farming in Mediterranean waters that describe the activity as a sustainable aquaculture practice as well as a carbon sink (Tamburini et al., 2019;Tamburini et al., 2020;Turolla et al., 2020;Martini et al., 2022;Tamburini et al., 2022). ...
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We are all familiar with the episodes in the deep time history of Earth that enabled life to emerge in such abundance. Episodes like the formation of a Moon large enough and near enough to cause tides in the Earth’s waters and rocks, a core of sufficient iron with sufficient angular momentum to generate a protective magnetosphere around Earth, and assumption of a planetary axis angle that generates the ecological variation of our seasonal cycles. The living things that did arise on this planet have been modifying their habitats on Earth since they first appeared. Modifications that include the greening of Earth by photosynthetic organisms, which turned a predominantly reducing atmosphere into an oxidising one, the consequent precipitation of iron oxides into iron ore strata, and the formation of huge deposits of limestone by calcifying organisms. The episodes on which we wish to concentrate are 1) the frequent involvement of marine calcifiers (coccolithophores, foraminifera, molluscs, crustacea, corals, echinoderms), that have been described as ecosystem engineers modifying habitats in a generally positive way for other organisms, and 2) the frequent involvement of humans in changing the Earth’s biosphere in a generally negative way for other organisms. The fossil record shows that ancestral marine calcifiers had the physiology to cope with both acidified oceans and great excesses of atmospheric CO2 periodically throughout the past 500 million years, creating vast remains of shells as limestone strata in the process. So, our core belief is that humankind must look to the oceans for a solution to present-day climate change. The marine calcifiers of this planet have a track record of decisively modifying both oceans and atmospheres but take millions of years to do it. On the other hand, humanity works fast; in just a few thousand years we have driven scores of animals and plants to extinction, and in just a few hundred years we have so drastically modified our atmosphere that, arguably, we stand on the verge of extinction ourselves. Of all Earth’s ecosystems, those built around biological calcifiers, which all convert organic carbon into inorganic limestone, are the only ones that offer the prospect of permanent net removal of CO2 from our atmosphere. These are the carbon-removal biotechnologies we should be seeking to exploit.
... In several recent publications we have advocated that shellfish farmers should greatly expand their production specifically to generate more shell to sequester atmospheric carbon Moore, 2020Moore, , 2021Moore et al., 2021aMoore et al., , 2021bMoore et al., , 2022Petros et al., 2021). Our core conviction is that humankind must look to the oceans for the solution to the excess CO2 in the atmosphere that drives climate change, and that marine calcifiers (coccolithophores, Foraminifera, Mollusca, Crustacea, corals) are the tools that will provide that solution. ...
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Today's marine calcifiers (coccolithophore algae, Foraminifera (protists), Mollusca, Crustacea, corals) remove carbon dioxide (CO2) from the atmosphere, converting it into solid calcium carbonate (CaCO3) which is stable for geological periods of time. Consequently, these organisms could serve as a biotechnological carbon capture and storage mechanism, contributing to control of climate change. Two criticisms are made about the use of this straightforward biotechnology as a carbon sequestration tool: (i) ocean acidification which has already occurred has allegedly been shown to cause reduced shell formation in calcifiers. (ii) The biological calcification reaction that precipitates CaCO3 crystals into the shells is itself "…the major way by which CO2 is returned to the atmosphere". In this review we assess the evidence concerning both criticisms and find that both are scientific myths. Experiments showing that ocean "acidification" is damaging to calcifiers have all used experimental pH levels that are not projected to be reached in the oceans until the next century. Furthermore, there are several reports showing that calcification is improved in today's less alkaline/high CO2 conditions in tested calcifiers. The claim that precipitation of CaCO3 in the calcification reaction is a source of CO2 to the atmosphere is a misunderstanding of calcifier physiology and molecular cell biology, and an oversimplification of ocean chemistry. The positive message remaining is that the world's aquaculture industries already operate the biotechnology that can control atmospheric CO2. By scaling it up, an enormous and sustainable contribution could be made toward atmosphere remediation. [243 words]
... are good for us in so many ways) and concentrate on marine calcifiers (Moore, 2020(Moore, , 2021881 Moore et al., 2021c). 882 ...
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We are all familiar with the more notable episodes in the deep time history of Earth that enabled life to emerge in such abundance on this planet. Episodes like the collision with Theia that resulted in formation of a Moon large enough and close enough to cause tides in the Earth’s waters and rocks, donation of sufficient iron with sufficient angular momentum to generate a protective magnetosphere around Earth, and assumption of a planetary axis angle that generates the ecological variation of our seasonal cycles. The living things that did arise on this planet have been bioengineering the Earth since they first appeared. The familiar episodes in these instances include the greening of Earth by photosynthetic organisms, which turned a predominantly reducing atmosphere into an oxidising one. The consequent precipitation of iron oxides into iron ore strata, and the formation of huge deposits of limestone by calcifying organisms. The episodes on which we wish to concentrate are (a) the frequent involvement of marine calcifiers (coccolithophores, foraminifera, molluscs, crustacea, corals) in bioengineering the atmosphere in a generally positive way for other organisms, and (b) the frequent involvement of humans in bioengineering the Earth’s biosphere in a generally negative way for other organisms. Our core belief, that humankind must look to the oceans for a solution to climate change, is based on the fact that periodically, over the past 500 million years, the fossil record shows that ancestral marine calcifiers had the physiology to cope with both acidified oceans and great excesses of atmospheric CO2, creating vast remains of shell as limestone strata. The marine calcifiers of this planet have a track record of decisively modifying both acidified atmospheres and atmospheres containing excess CO2 but take millions of years to do it. On the other hand, humanity works fast; in just a few thousand years we have driven scores of animals and plants to extinction, and in just a few hundred years we have so drastically modified our atmosphere that we stand on the verge of extinction ourselves. We want to develop the thesis that if we combine two proven special talents - the ability of calcifiers to remove carbon from the atmosphere and the human ability to get things done quickly, we might be able to navigate our way out of the climate crisis of which we are now so aware. We maintain that humanity could engineer this planet’s atmosphere into a less hazardous state, cultivate nutritious meats for human food and animal feeds, improve biodiversity and conservation throughout the oceans, and repair most of the damage that industrial humans have inflicted on planet Earth.
... Our case for the calcifiers is presented in our recent publications (Heilweck & Moore, 2021;Moore, 2020Moore, , 2021Moore et al., 2021a & b) so we will not repeat it here. We will reiterate that it is the certainty and permanence of the removal of CO2 from the atmosphere that would make a biotechnology using calcifying organisms so attractive. ...
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Petros, P., Heilweck, M. & Moore, D. (2021). Saving the planet with appropriate biotechnology: 5. An action plan/Salvando el planeta con biotecnología apropiada: 5. Un plan de acción. Mexican Journal of Biotechnology, 6(2): 1-60. DOI: https://doi.org/10.29267/mxjb.2021.6.2.1. We evaluate suggestions to harness the ability of calcifying organisms (molluscs, crustacea, corals and coccolithophore algae) to remove permanently CO2 from the atmosphere into solid (crystalline) CaCO3 for atmosphere remediation. Here, we compare this blue carbon with artificial/industrial Carbon dioxide Capture & Storage (CCS) solutions. An industrial CCS facility delivers, at some cost, captured CO2, nothing more. But aquaculture enterprises cultivating shell to capture and store atmospheric CO2 also produce nutritious food and perform many ecosystem services like water filtration, biodeposition, denitrification, reef building, enhanced biodiversity, shoreline stabilisation and wave management. We estimate that a mussel farm sequesters three times as much carbon as terrestrial ecosystems retain. Blue carbon farming does not need irrigation or fertiliser, nor conflict with the use of scarce agricultural land. Blue carbon farming can be combined with restoration and conservation of overfished fisheries and usually involves so little intervention that there is no inevitable conflict with other activities. We calculate that this paradigm shift (from ‘shellfish as food’ to ‘shellfish for carbon sequestration’) makes bivalve mollusc farming and microalgal farming enterprises, viable, profitable, and sustainable, alternatives to all CCUS industrial technologies and terrestrial biotechnologies in use today.
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Today’s marine calcifiers (coccolithophore algae, Foraminifera [protists], Mollusca, Crustacea, Anthozoa [corals], Echinodermata) remove carbon dioxide (CO 2 ) from the atmosphere, converting it into solid calcium carbonate (CaCO 3 ) which is stable for geological periods of time. These organisms could serve as a biotechnological carbon capture and storage mechanism to control climate change. Two criticisms made about this are: (i) ocean acidification has allegedly been shown to cause reduced shell formation in calcifiers; (ii) the calcification reaction that precipitates CaCO 3 crystals into the shells is alleged to return CO 2 to the atmosphere. In this review we assess the evidence concerning such criticisms and find reasons to doubt both. Experiments showing that ocean acidification is damaging to calcifiers have all used experimental pH levels that are not projected to be reached in the oceans until the next century or later; today’s oceans, despite recent changes, are alkaline in pH. Claiming precipitation of CaCO 3 during calcification as a net source of CO 2 to the atmosphere is an oversimplification of ocean chemistry that is true only in open water environments. Living calcifiers do not carry out the calcification reaction in an open water environment in equilibrium with the atmosphere. The chemistry that we know as life takes place on the surfaces of enzymatic polypeptides, within organelles that have phospholipid membranes, contained in a cell enclosed within another phospholipid bilayer membrane specifically to isolate the chemistry of life from the open water environment. Ignoring what is known about the biology, physiology, and molecular cell biology of living organisms, calcifiers of all types especially, leads to erroneous conclusions and deficient advice about the potential for calcifier biotechnology to contribute to atmosphere remediation. Net removal of CO 2 from the atmosphere by calcifiers is only achieved by the CaCO 3 stored in the shell, coccoliths, or foram tests that are left when they die. To capitalise on this requires a change in paradigm towards cultivating calcifiers for their CaCO 3 rather than their meat or other products. We conclude that the world’s aquaculture industries already operate the biotechnology that, with massive and immediate global expansion, can contribute to sustainably controlling atmospheric CO 2 levels at reasonable cost and with several positive benefits in addition to carbon sequestration.
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Today’s marine calcifiers (coccolithophore algae, Foraminifera [protists], Mollusca, Crustacea, Anthozoa [corals], Echinodermata) remove carbon dioxide (CO 2 ) from the atmosphere, converting it into solid calcium carbonate (CaCO 3 ) which is stable for geological periods of time. These organisms could serve as a biotechnological carbon capture and storage mechanism to control climate change. Two criticisms made about this are: (i) ocean acidification has allegedly been shown to cause reduced shell formation in calcifiers; (ii) the calcification reaction that precipitates CaCO 3 crystals into the shells is alleged to return CO 2 to the atmosphere. In this review we assess the evidence concerning such criticisms and find reasons to doubt both. Experiments showing that ocean acidification is damaging to calcifiers have all used experimental pH levels that are not projected to be reached in the oceans until the next century or later; today’s oceans, despite recent changes, are alkaline in pH. Claiming precipitation of CaCO 3 during calcification as a net source of CO 2 to the atmosphere is an oversimplification of ocean chemistry that is true only in open water environments. Living calcifiers do not carry out the calcification reaction in an open water environment in equilibrium with the atmosphere. The chemistry that we know as life takes place on the surfaces of enzymatic polypeptides, within organelles that have phospholipid membranes, contained in a cell enclosed within another phospholipid bilayer membrane specifically to isolate the chemistry of life from the open water environment. Ignoring what is known about the biology, physiology, and molecular cell biology of living organisms, calcifiers of all types especially, leads to erroneous conclusions and deficient advice about the potential for biotechnology to contribute to atmosphere remediation. We conclude that the world’s aquaculture industries already operate the biotechnology that, with massive and immediate global expansion, can contribute to sustainably controlling atmospheric CO 2 levels at reasonable cost and with several positive benefits in addition to carbon sequestration.
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2. Moore, D., Heilweck, M. & Petros, P. (2022). Cultivate Shellfish to Remediate the Atmosphere. In: Aquaculture: Ocean Blue Carbon Meets UN-SDGS. (eds D. Moore, M. Heilweck & P. Petros), Chapter 2. pp. 35-63. A volume in the Sustainable Development Goals Series. Springer, Cham. ISBN: 9783030948450. DOI: https://doi.org/10.1007/978-3-030-94846-7_2. 2.1 In this Chapter… The very recent research that indicates that massive tree planting is not the panacea that many believe, is discussed. Photosynthetic carbon capture by trees and other green plants is widely thought to be our most effective strategy to limit the rise of CO2 concentrations in the atmosphere by pulling carbon from the atmosphere into the sinks represented by the plant body and the soil. However, practical experience indicates that putting such plans into effect could do more harm than good to our environment. Planting trees can release more carbon from the soil sink than the plants sequester into their biomass. And, in all cases, the plant biomass sink is only ever a temporary sequestration because when the plant dies its biomass rots, and its sequestered carbon is returned to the atmosphere. Forests should be planted for the intrinsic values of forests; for clean, oxygenated air, natural biodiversity, and restorative conservation of terrestrial ecosystems, rather than tree planting as a means to sequester atmospheric CO2. This chapter describes the basic message of the book, which is that shellfish cultivation as a carbon sequestration strategy is both more immediately rewarding and more helpful in the very long term. A considerable proportion of shellfish biomass is represented by the animals’ shells, and shellfish shell is made by converting atmospheric CO2 into crystalline calcium carbonate which is stable for geological periods of time. The essentials of habitat conservation, ecosystem balance and carbon sequestration for carbon offsetting programmes are also introduced; topics developed in chapters which follow. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2022 D. Moore et al., Aquaculture: Ocean Blue Carbon Meets UN-SDGS, Sustainable Development Goals Series. FULL TEXT available from this URL: https://doi.org/10.1007/978-3-030-94846-7_2
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4. Heilweck, M. (2022). The High Seas Solution. In: Aquaculture: Ocean Blue Carbon Meets UN-SDGS. (eds D. Moore, M. Heilweck & P. Petros), Chapter 4, pp. 97-130. A volume in the Sustainable Development Goals Series. Springer, Cham. ISBN: 9783030948450. DOI: https://doi.org/10.1007/978-3-030-94846-7_4. 4.1 In this Chapter… The case is made for greater use of the High Seas to replace forage fish with mussels in the diet of farmed fish and produce the increasing amounts of food that will be required by the growing human population, while at the same time pulling down carbon from the atmosphere with bivalve cultivation. The vision is to preserve the oceans as a healthy and sustainable food source for mankind by emphasising conservation and ecosystem balance beyond coastal waters. The plans are for huge (centralised) bivalve mollusc farming facilities on the high seas, using factory ships and offshore factory rigs (re-purposed disused oil rigs?) located on seamounts outside Exclusive Economic Zones and employing Perpetual Salt Fountains on the flanks of the seamount to bring nutrients to the farms. If properly designed (and the design and building capabilities exist throughout the offshore industries around the world), this will immediately provide (i) feed for animals and food for humans, (ii) sustainable marine ecosystems, and (iii) permanent atmospheric carbon sequestration in the form of reefs of bivalve shells. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2022 D. Moore et al., Aquaculture: Ocean Blue Carbon Meets UN-SDGS, Sustainable Development Goals Series. FULL TEXT available from this URL: https://doi.org/10.1007/978-3-030-94846-7_4
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We deal with the current artificial/industrial Carbon Dioxide Capture, Utilisation .and Storage (CCUS) solutions and show their power and potential in curtailing greenhouse gas (GHG) emissions. Key evaluation models of sustainability for current carbon capture and storage (CCS) infrastructure are used to explain what problems could arise and potential ways to avoid the likely risks through drastic changes in fundamental attitudes. The shortfalls of each industrial solution are also presented in the context that all activities should be carried out with due regard for long-term human and environmental well-being, rather than economic growth alone.
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The potential for global forest cover The restoration of forested land at a global scale could help capture atmospheric carbon and mitigate climate change. Bastin et al. used direct measurements of forest cover to generate a model of forest restoration potential across the globe (see the Perspective by Chazdon and Brancalion). Their spatially explicit maps show how much additional tree cover could exist outside of existing forests and agricultural and urban land. Ecosystems could support an additional 0.9 billion hectares of continuous forest. This would represent a greater than 25% increase in forested area, including more than 200 gigatonnes of additional carbon at maturity.Such a change has the potential to store an equivalent of 25% of the current atmospheric carbon pool. Science , this issue p. 76 ; see also p. 24
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Chapter
The carrying capacity concept for bivalve aquaculture is used to assess production potential of culture areas, and to address possible effects of the culture for the environment and for other users. Production potential is depending on physical and production carrying capacity of the ecosystem, while ecological and social carrying capacity determine to what extent the production capacity can be realized. According to current definitions, the ecological carrying capacity is the stocking or farm density of the exploited population above which unacceptable environmental impacts become apparent, and the social capacity is the level of farm development above which unacceptable social impacts are manifested. It can be disputed to what extent social and ecological capacities differ, as unacceptable impacts are social constructs. In the approach of carrying capacity, focus is often on avoiding adverse impacts of bivalve aquaculture. However, bivalve populations also have positive impacts on the ecosystem, such as stimulation of primary production through filtration and nutrient regeneration. These ecosystem services deserve more attention in proper estimation of carrying capacity and therefore we focus on both positive and negative feedbacks by the bivalves on the ecosystem. We review tools that are available to quantify carrying capacity. This varies from simple indices to complex models. We present case studies of the use of clearance and grazing ratio’s as simple carrying capacity indices. Applications depend on specific management questions in the respective areas, the availability of data and the type of decisions that need to be made. For making decisions on bivalve aquaculture, standards, threshold values or levels of acceptable change (LAC) are used. The FAO framework for aquaculture is formulated as The Ecosystem Approach to Aquaculture. It implies stakeholder involvement, and a carrying capacity management where commercial stocks attribute in a balanced way to production, ecological and social goals. Simulation models are being developed as tools to predict the integrated effect of various levels of bivalve aquaculture for specific management goals, such as improved ecosystem resilience. In practice, bivalve aquaculture management is confronted with different competing stocks of cultured, wild, restoration and invasive origin. Scenario models have been reviewed that are used for finding the balance between maximizing production capacity and optimizing ecological carrying capacity in areas with bivalve aquaculture.
Chapter
The role of marine bivalves in the CO2 cycle has been commonly evaluated as the balance between respiration, shell calcium carbonate sequestration, and CO2 release during biogenic calcification; however, this individual-based approach neglects important ecosystem interactions that occur at the population level, e.g. the interaction with phytoplankton populations and benthic-pelagic coupling, which in turn can significantly alter the CO2 cycle. Therefore, an ecosystem approach that accounts for the trophic interactions of bivalves, including the role of dissolved and particulate organic and inorganic carbon cycling, is needed to provide a rigorous assessment of the role of bivalves as a potential sink of CO2. Conversely, the discussion about this potential role needs to be framed in the context of non-harvested vs. harvested populations, given that harvesting represents a net extraction of matter from the ocean. Accordingly, this chapter describes the main processes that affect CO2 cycling and discuss the role of non-harvested and harvested bivalves in the context of sequestering carbon. A budget for deep-fjord waters is presented as a case study.