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Almost 71% of the Earth surface is covered by oceans. That leaves about 148.5 million square kilometres of land. More than 5% of that land surface is covered by wetlands. Wetlands form a very broad category of ecosystems that includes all land systems that are periodically flooded by water. It can be the swamps along a natural river, where periodical or seasonal flooding from the river, associated with the variations in the underlying watertable, influence the type of biological communities that develop. Another example are the salt marshes that are found along the sea costs, where brackish water has direct impact on life forms.

Raised bogs

Raised bogs develop in a very specific process that requires thousands of years. To start, there needs to be a depression in the ground, for example the ones left behind 10’000 years ago when the last glaciation ended and the slow retiring of ice towards the north moved and modified the surface soil composition and ground shape. Some soil formations present very little permeability, which means that instead of flowing away, water accumulated creating a lake or a pond. At the beginning, the usual organisms, such as sedges, water lilies, etc. colonised the pond. Without running water, the oxygen, needed by most decomposers to survive, starts to decrease. With less and less decomposers in the community, the organic matter starts to accumulate, eventually filling up the pond. The accumulated organic matter that is only slightly decomposed mostly by anaerobic bacteria, is called peat.

In the meantime, at the surface, the combination of lack of air, abundance of water and increasing amount of only partially decomposed organic matter results in the soil becoming more and more acidic and therefore hostile for many organisms; plants, animals, protists, fungi and bacteria alike. The communities of organisms living in the ecosystems start to shift, with many species dying out and other starting to thrive. Sphagnum mosses are one of the main plants dominating raised bogs. Contrary to other organisms, they never stop to grow. While the bottom of the plant becomes part of the peat, at the top the little plant is alive and keeps photosynthesising and growing.

Sphagnum mosses

After a while, through the accumulation of organic matter and the active growing of Sphagnum mosses, the surface of the bog rises above the ground level, becoming a raised bog. At this point, the plants from raised boga get water exclusively from the rain, and not from the ground surface. Because rain water contains almost no nutrients, the conditions in the raised bogs become extremely difficult and the communities surviving are very specific to these ecosystems.

Peat extraction

Raised bogs are also called ombrotrophic bogs because of their dependence on atmospheric water. Ombrotrophic bogs, together with other forms of peatlands, have been exploited for centuries for peat extraction. Peat is basically very concentrated organic matter, which makes it a good fuel, producing more heat and for longer than woods, while being much more accessible than coal. Nowadays, it is mostly used to fertilise gardens. All it needs is for the water to be drained and the peat can be extracted brick by brick.

Loss of biodiversity

To extract peat, or free the land for agricultural or building purpose, large proportions of peatlands worldwide have been destroyed. Not only does the destruction of peatlands directly eliminate the communities of endemic organisms, the loss of these ecosystems has a huge indirect impact on some species, such as migrating birds that need wetlands to break their journey, of amphibians and birds that need them for a space where to reproduce.

From carbon sink to carbon source

Unfortunately, the tragic loss of biodiversity is not even the only catastrophe relating to raised bogs drainage. Peat is composed of concentrated organic matter. It is concentrated and accumulates because of the presence of water and the lack of oxygen that in combination make it extremely difficult for decomposers to use it as a source of food. As soon as the drainage starts through, peat starts to dry out. Exposed to the air and the oxygen, decomposers start their feast and quite rapidly the organic matter is consumed and transformed into carbon dioxide. So instead of carbon sinks, peatlands turn into carbon sources for the atmosphere.

Peatlands protection

It is estimated that peatlands globally contain twice the amount of carbon that is in all the trees in the world, although they cover only 3% of land surface, compared to the 31% covered by trees. Carbon release in the atmosphere through human pollution since the industrial revolution has already disrupted the natural gas exchange balance. There is therefore no doubts that we must put priority in protecting peatlands ecosystems and where possible trying to restore them to their natural function as carbon sinks.

For a long time now I have been wondering wether to create or not an electronic version of The hidden world of diatoms book. I even posted a poll on twitter to ask my followers what they thought about this. The majority answered that yes I should do it.

Pro

The theoretical advantages of an ebook are quite obvious, starting from the trees saved by not printing on paper (although I am totally ignorant of how a 56 pages book compares to the energy needed for the use of electronic devices). It is also much quicker to get (especially when you do not enjoy the cheap shipping costs of big distributors and have to go through normal snail mail) and because of the former two reasons, you also get it for cheaper. I am a constant reader, so I also appreciate the weight that you don’t have to carry around when all you need to get your fix, even on a long trip, can squeeze in a tablet.

As I already admitted, I do have a e-reader myself, so it should have been a no brainer that as soon as I wrote my book, I would create the electronic version as well. Actually, most self-published authors nowadays do that in the first place. There are even templates on most e-book distributors, where you just add your text and pictures and they make it all for you. So what’s the problem?

Con

The hesitation for me lays in the romantic view I have for books. For me it is not only the information that goes through the eyes and into the brain to release dopamine, it is all the action of holding a book, feeling the paper, turning the pages. Maybe it has to do with my age and upbringing as well, but to sit or lay down with my kids holding an electronic device and tap on it, just does not make it. Being surrounded by actual books, seeing them, is part of the décor. It makes you feel home.

Yes, you got me, books are the one thing I cannot refrain myself from buying, as my daughter very well knows, it is enough to convince me to put my foot in the bookshop, to be sure that I will buy her at least one new book, even though I had promised that this time it would not happen. What can I do, there are worst habits to have and to fight….

What brought me then to finally create the ebook of The hidden world of diatoms? Well, I consider myself lucky to be part of the wonderful world of scientists. Attending the VIII European Congress of Protistology- ISOPJoint meeting I was reminded that I am part of that world, even though I have left the academic career. But the goal of this book, and the ones that will follow in the series, is to reach every and all kids, not only the ones that have a contact in the scientific world. And to do that, to reach children from all context of life, I believe I have to acknowledge that my romantic view of books is not the only one out there, and maybe more importantly, most people out there do not have the possibility or the willingness to go for the papery and more expensive choice.

In conclusion, it is my pleasure to introduce you to The hidden world of diatoms- ebook, available for the launching price of £4.50 for the first 2 days of publication, and £5.90 after that.

Enjoy and please leave a review or contact me if you think we can improve.

The 15^th of August marked the first birthday of thehiddenworld.co.uk. What an incredible year it has been. I am not sure wether it’s the business or the author who’s grown the most during that time.

How are we doing?

Looking back I think that it couldn’t have been a better year than what it turned out to be. The first big step happened in November, with the kickstarter crowdfunding campaign. What a success. That really got things moving, allowing the book to go to print and getting us to the second biggest success of the year: the e-shop opening on the 18^th of February. Since then, the book has sold about 100 copies from the kickstarter campaign rewards, 20 copies from the e-shop, about 40 copies in person, 6 copies at the school book event, and more than 40 copies at the protistology conference I attended at the end of July (www.ecop2019.org). It seems that in average a book sells about 250-300 copies the first year, even when traditionally published (ref) so if that’s a rule to go by, I’d say that 200 copies for the first semester is quite a success.

Reaching for the world

For all the beautiful reviews I have received, I find myself stuck in the limbo between the inner circle of my connections and the outside circle of the general public. Once all friends and family members, work colleagues, diatoms-lovers, and some social media followers have a copy of the book, how to reach the rest of the world? Social media for sure allow to reach people (and bots) all over the world, and pave the path to a much larger audience. But in terms of sales, school book events and scientific conferences seem to be the best way to go, for now. I would love to attend a book fair or book festival, but it is hard to get into those without a publisher, or at least an agent. I am looking into getting an agent, eventually. Only problem is, one needs money to get an agent, to advertise, and go to conferences, which in turn are supposed to actually earn the money you need to pay for them Catch 22, sounds familiar?

What’s next?

Since thehiddenworld.co.uk came to life one year ago, I have started to see myself as a writer. It is a bit ironic therefore, that since then I have spent my time working on a website, creating instafriendly pictures, and learning how to tweet (although that’s a language I still have to master). On the side, I read all I could about crowdfunding, printing, postage methods, and self-publishing. I had been warned, not to surf on the wave of excitement created by the publishing of your first book, and launching directly on writing the sequel, else the risk is great that the first baby gets left in a corner. Indeed as I already mentioned, marketing your own book is a full-time job (at least at the mental level).

But be reassured, I have found time to start working on my second book. It’s a work in progress, at the moment on hold, while I concentrate on a proposal I am writing to get a grant to fund illustrations and printing. I will tell you more about it when the time comes.

For now, let me just tell you, it has been the most professional-life changing year for me. My comfort zone has been shaken and expanded many a time. My fear levels have been on a terrifying and exhilarating roller-coaster. And I am definitely going to do my best to keep following this path.

Diatoms represent a respectable proportion of the ocean primary production, although their actual biomass varies considerably in time and space, depending on water temperature, salinity and nutrient content. Their abundance can increase rapidly during particularly good conditions. For example during the spring oceanic bloom when, due to their rapid growth, they outgrow the other groups in the phytoplankton.

Phytoplankton constitute the base of the ocean food web. As such, diatoms are in fact eaten by a long list of herbivores and grazers of the seas. Dinoflagellate and ciliates are part of the zooplankton feeding directly on diatoms, the zooplankton itself being then fed upon by invertebrates and so on.

But diatoms are not as defenceless as they might seem. Many species produce defensive chemicals when the cell is disrupted. Those chemicals, called oxylipins*, have a direct impact on the cell reproduction of zooplankton, such as ciliates, decreasing their population and therefore the diatom grazing. Moreover, the decreased density of some grazers allows other smaller species to increase their density. Those species feed on smaller (pico- and nano-) phytoplankton instead of diatoms, making the environment safer.

Oxylipins presence in the environment seems to have an enhancing effect on copepods hunger for ciliates, indirectly decreasing ciliates grazing on diatoms.

Another compound produced by diatoms, possibly as a form of defence, appears to have many interesting properties. It is called marennine, and it is a blue-green pigment produced by a few species in the marine genus Haslea. Marennine, beside being a natural, water-soluble pigment, also has antibacterial, antiviral, antifungal and antioxydant capacities, and significantly affects early developmental stages of some organisms, such as mussels and sea urchins.

In conclusion, diatoms are indeed at the bottom of the ocean food web, but that does not mean that their abundance and species richness is at the mercy of herbivores and upper layers of the web, diatoms still have their say in it.

*Oxylipins is a group of chemicals that derive from the oxygenation of fatty acids, in the case of diatoms the fatty acids constituent of the cell wall, and their oxygenation is triggered by the rupture of the cell wall.

REF

• Falaise, C. et al. (2019). Harmful or harmless: Biological effects of marennine on marine organisms. Aquatic toxicology.
• Franzè, G. et al. (2017). Diatom‐produced allelochemicals trigger trophic cascades in the planktonic food web. Limnology and Oceanography.
• Gastineau, R. et al. (2014). Marennine, promising blue pigments from a widespread Haslea diatom species complex. Marine Drugs.
• Pennisi, E. (1999). Diatoms are Copepods contraceptives, Sciencemag.org.
• Varrella, S. et al.(2014). Molecular Response to Toxic Diatom-Derived Aldehydes in the Sea Urchin Paracentrotus lividus. Marine Drugs.

Diatoms are unicellular organisms, and as such, they mostly reproduce asexually. In other protists, that means cellular duplication, but in diatoms things are made slightly more complex by the presence of they frustule. The frustule is the protective shell that diatoms produce from Silica, to protect themselves. Glass-like in structure, frustule cannot simply be « hatched » by the duplicating cell. The trick is in the shape of the frustule. Not always obvious to the untrained eyes, frustules are always formed by two component, one of which is just enough smaller than the other one to be encased in it.

Once the diatom cell is ready to reproduce, the two parts of the frustule separate under pressure of the growing mother cell. Once mitosis* happened, each of the two new cells leaves with one half of the frustule that becomes its bigger half, and goes on to produce a smaller half of their new frustule. After a certain number of reproduction cycles, things become rather awkward for the daughter cell that inherits the smaller part of the frustule. Indeed at each reproductive cycle, the size of the frustule becomes smaller and smaller, until it is far from ideal.

At that point the diatom change its strategy and switch to a sexual reproduction. The cell goes through meiosis** and the resulting gametes*** fertilise and become the brand new diatom that produce a perfectly respectable frustule size.

* a type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent

** a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent

***a mature male or female germ cell, with half the parent genetic material, able to unite with another of the opposite sex

Diatoms photosynthesise to produce their food, therefore they need light to survive. Which is why they are only found on the surface of lakes and rivers, wetlands and seas, as deep in the water as the sunlight can reach. Not all diatom species like the same amount of light though, or the same salinity (concentration of salt in water), oxygen, acidity (pH), saprobity (concentration of pollution), temperature, and other water conditions or even the current velocity in freshwater streams. Many different species can coexist in a community in a set of conditions, but if those conditions change, some of the species will thrive and increase their importance in the community, while others might die and be replaced by other species more suited for that particular set of conditions.

In general diatoms prefer cold water, arguably because they evolved at a time when Earth temperature was lower than nowadays. Some species like really cold water. There are even an approximate 200 species that grow on ice in the Arctic.

This specific sensibility of diatoms to ecological conditions is widely used to describe water quality. Indeed the presence/absence of a particular species, or ratio of species can be used as an indicator of water pollution.

Diatoms specific sensitivity is also very useful for paleolimnological studies. Paleolimnology is the study of sediments to extrapolate information on past environmental conditions (Paleon=old, limne=lake, logos=study). Sediment samples in very old lakes are extracted at different depths. The deeper is the sediment found, the older it is. The diatom species in the samples are determined by identification of the frustules and their abundance. Depending which community is found, scientists are able to estimate the particular environmental conditions that were present at that time in history in that lake.

A third branch of science can exploit diatoms specific sensitivity, forensic science, and more specifically in case of a dead body found in aquatic environment. Forensic investigations mainly aim at answering two questions, the cause of death and where it happened. In the case of a body found in water, the study of the diatoms community, and testate amoebae communities, can help determine if the person died where the body was found, or if it died somewhere else and was transported there afterwards.

Such a small organisms, and so many amazing contributions to our life.

What happens to diatoms’ shells when they die?

When diatoms die, their shell, the frustule, is not eaten and does not decompose, instead it sediments and accumulates to the bottom of the water. When that happens for millions of years in a lake or a sea, the accumulation of billions of diatom frustules forms a layer at the bottom of it. In some places those seas and lakes are not there anymore, they dried out, making the deposits of frustules, called diatomaceous earth (DE), available for extraction.

The DE was first discovered by Peter Kasten in 1836 in Northern Germany. The region has been exploited for DE since then, but since the first world war extraction has occurred all over the world, from the USA, to the Czech Republic, from China to Algeria and Mexico.

The very first significant impact of DE use was developed by Alfred Nobel. He discovered that nitroglycerin, a liquid explosive, when mixed and absorbed by DE becomes more stable, which makes it much safer to transport. He patented the mixture and called it dynamite in 1867. The same absorbance capacity of DE is used in the production of pets litter.

Another important discovery was made around 1890 by Wilhelm Berkefeld. He discovered that thanks to the porosity of DE, if pressed into a cylinder, it could act as a filter for water. He called them filter candles. They helped fight the cholera epidemic in Hamburg, Germany, in 1892. Since 1950, filter candles are also used to clarify beer, and other forms of the same filtering capacity are used for swimming pool filters, fish tanks filters, and also in laboratories.

Abrasion is another characteristic of frustules that has been exploited for decades, as a component of toothpaste and as a natural effective pesticide in agriculture. Indeed the abrasion capacity of DE damages the lipid layer on insect exoskeleton, modifying its permeability and making the insects vulnerable to dehydration.

Quite recently, a new discovery brought diatom’s frustules to a new light. In their beautiful and intricate structure there are innumerable tiny holes that interfere with the direction of light waves. This means that looked at from different angles, the same structure assumes different colours. It is called iridescence. Mixed to paint and other materials, DE could bring the power of iridescence to make-up and fabric, but it could also be used by engineer to enhance the efficiency of solar panel to capture solar energy.

Diatoms are amazing!

On the 18^th of February, with the delivery of 83 boxes, The hidden world of diatoms has officially changed status, from being a dream project to becoming reality. I knew, obviously, that the moment was coming, but being surrounded by boxes filled with copies of my book was incredible, almost unbelievable.

Reality also means, that The hidden world of microorganisms is now a business, and as such it needs to be managed. The first job has been to ship out the rewards to all my kickstarter backers. Yet another occasion to thank them for their trust, but also to organise the most efficient set up of the headquarters. I had to accept that maybe having the office in the attic was not the best idea, at least not when you have 83 boxes to bring up two floors, and down again once they are ready to ship to their new homes, so some things had to be reorganised.

Since then a few books have arrived at their destination and I am proud to say that I have received very good reviews that I would like to share with you:

“I loved your book. What a beautiful experience. You led us to a great journey through the universe of living things! It’s also a piece of art. The drawings are so lovely, and make it also very enjoyable for the eyes! Congratulations!” -MB-

“Absolutely fantastic. My child loved it. She found the book engaging and informative (even I learnt lots).” -MSA-

“Beautifully illustrated and perfectly pitched for children (and adults!) to introduce about the often unknown yet incredibly important world of diatoms. Lovely book.” -EW-

I’ll stop here, because I don’t want to bore you with too many, but each and every comment is very much appreciated. One comment has broken my heart though, alas the inevitable mistake that always manage to slip through the innumerable checks has happened. Well, here it is: I mis-captioned one of the diatom species shown on the microscope pictures at the end of the book. I expect most of you would not have guessed, but the beautiful specimen shown on page 52 at the top, is not Diploneis finnica, it is actually called Encyonema caespitosum. If I will be lucky enough to have to run a reprinting, I promise I will have this changed, but for now, I apologise to the diatomists out there that might be totally horrified by my mistake, and to everyone else for the misinformation.

Probably the most important part of a business is marketing, so I have also started to work on that. I am quite proud of the little video I created and posted on my socials at the end of last week. I admit it took me quite some time to get it right, what with the squeaking chair, the giggling daughter mocking my accent and the word stumbling. But it was fun. And now it’s out there living its life and hopefully spreading interest for the book. If you liked it, share it, if you didn’t, please let me know why, so I can improve it.

There has been a lot of talking about climate change in the last years. But what do we know about the impact of climate change on diatoms? Here is a short summary of some of the research on the consequences of climate change on diatoms.

Climate change and in particular the augmentation of carbon dioxide (CO2) in the air has huge consequences on life in the ocean. Nowadays, the major source of air pollution comes from traffic emissions.
Carbon dioxide is constantly absorbed into the water, so the more there is in the air, the more enters the ocean. When CO2 concentration in water increases, water becomes more acidic and organisms that live in it suffer the consequences of the changing environment. Some species will thrive, some will die, most of them will have to adapt.

Diatoms are an extremely important contributor to the marine food web. Through photosynthesis they create 40% of the total organic matter produced in the ocean, the phytoplankton, that is then eaten by many other organisms, such as krill, fish, whales, etc. Many scientific projects research and experiment in the lab the consequences that the increased acidification of oceans will have on marine ecosystems, as it will indirectly impact our ways of life as well.

Although the direct impact of an increasing concentration of carbon dioxide would be an increase in diatoms growth, the indirect consequence of the former would be deleterious. Indeed, when acidification increases in water, all the nutrients that diatoms and other primary producers need to survive and grow, will be affected. Some become unavailable or limiting, like iron or nitrogen, whereas others become toxic.

The answer is far from being simple. The consequence of water acidification could be dwarfed by the effect of decreased availability of nitrogen, an essential nutriment for diatoms. On the other hand, the effect of water acidification on diatom performance could also depend on access to sunlight, which would imply a gradient of impact with light decreasing with the distance from the surface. The good news is that it looks like increased CO2 concentration in water also increases diatoms capacity for resilience4, which means that diatoms could be able to tolerate a certain amount of water acidification without a drastic change in their community composition. At least to a certain point.

uk-air.defra.gov.uk/air-pollution/causes

Physical and biogeochemical modulation of ocean acidification in the central North Pacific.
John E. Dore, Roger Lukas, Daniel W. Sadler, Matthew J. Church, and David M. Karl
PNAS: 106 (30) 12235-12240. 2009.
https://www.pnas.org/content/106/30/12235

Interactive Effects of Ocean Acidification and Nitrogen-Limitation on the Diatom Phaeodactylum tricornutum.
Wei Li, Kunshan Gao, and John Beardall PLoS One: 7(12): e51590. 2012.
https://journals.plos.org/plosone/article…

Ocean acidification conditions increase resilience of marine diatoms.
Jacob J. Valenzuela, Adrián López García de Lomana, Allison Lee, E. V. Armbrust, Mónica V. Orellana & Nitin S. Baliga. Nature Communications: volume 9, Article number: 2328. 2018.
https://www.nature.com/articles/s41467-018-04742-3

I am very happy to let you know that we are almost there. Little by little illustrations and text have come together, balancing colours and information to make it look the best it can. And I love it! A few details need to be corrected, then by tomorrow it is out to the press. Being new in this trade I totally underestimated the time needed to get everything together. I will let you know as soon as it is in press…you will probably hear me celebrating wherever in the world you are 😉

At one point I really thought it was going to be possible to hold the printed book in my hands before Christmas, so it was a bit frustrating having to postpone. I suppose every step of the process of self-publishing needs its time and will present its issues, but at least I am still in the scheduled time for the book launch on the website. By the way, I have been thinking of organising a book launch party here in Sheffield. For now I believe most followers are international, but maybe this way I’ll get to meet, and get known by, the locals. The question is, a party in the early afternoon with coffee/tea and cakes, or a party in the late afternoon with wine and nibbles? More about it later…