Marine algae in cyanotype by biologist Helena Cruz de Carvalho.

Cyanotype is one of the oldest forms of photography and is particularly suited to portray the wonderful life of the ocean. With almost otherworldly prints of marine algae, Helena Cruz de Carvalho breathes life into otherwise imperceptible creatures like diatoms, coccolithophores, and dinoflagellates. The delicate filigree of these organisms contrasts subtly with the Prussian blue of the ocean or the surrounding space—the 'cyan' that emerges during the processing of the artwork. This cross-pollination between science and art elevates both to a higher dimension, as the sublime of nature crystallizes into the 'stuff of dreams'. 

Text by Kathelijne Bonne. Cyanotype prints by  Helena Cruz de Carvalho (copyright: helena cc. / ADAGP).

"My work is grounded in the natural world, Helena says, materializing the beauty of the intangible and blurring the lines that separate reality, dream, imagination and the shadows within."

These little creatures, marine algae, are ubiquitous. They are present in every drop of the ocean. Together, they make up the largest biomass on Earth. They are at the base of the ocean's food web and more so than plants, they absorb carbon dioxide and produce oxygen keeping our planet habitable. This photosynthesizing 'phytoplankton' as it is collectively called, wanders around passively. As its Greek name suggests, φυτόν (phuton) 'plant' and πλαγκτός (planktos), 'wandering', it does not swim or move autonomously, but drifts along on currents – in swarms, trillions of them. 'Adrift' is the name of one of Helena's collections of cyanotype prints of phytoplankton, some of which are shown here.

DNA, dogma and diatoms

As part of her work as a biologist at the Institute of Biology at the École Normale Supérieure of PSL University in Paris, Helena investigates the ways in which both plants and phytoplankton respond to environmental change at cellular level: how they adapt to stress, to fluctuations in temperature, salinity, nutrient concentration and other factors ultimately linked to climate change. In doing so, she looks at how genetic material acts. Not only DNA plays a role, but pieces of non-coding RNA also appear to be crucial in how cellular processes are controlled. This transcends the limits of what is known as the "central dogma of molecular biology", which prescribes that transfer of information flows in one direction from DNA to RNA to protein. But beyond dogma, and whatever the mechanism is, marine phytoplankton does play an immeasurably important climate-regulating role. This is why Helena's research, focused on the nutrient response in diatoms in particular, is fundamental.

Diatoms are single celled microalgae that incorporate silica in their cell walls, creating intricate, glassy 'frustules', the shape of which has fascinated scholars for ages. They are excellent environmental indicators: Study of fossil diatoms in rock reveals information on climate fluctuations across geological time. Diatoms prefer cold waters and live close to the surface as they need light for photosynthesis. The total biomass of diatoms may be responsible for about 20 percent of Earth's oxygen production, making them the single most important lifeforms present in the ocean – or even earth? – today.

Prussian blue

Through a scanning electron microscope these anonymous particles of the sea come into focus in all their mathematical splendor, showing a geometric beauty that would otherwise remain unseen. While the raw microscope imagery is definitely intriguing, Helena selected the best imaged specimens to use in cyanotype art, infusing them with both a nostalgic and futuristic aura at the same time.

The cyanotype technique does not require a camera. A mixture of two light-sensitive iron salts is applied to a surface, e.g. on watercolor paper. Semi-translucent objects such as flowers as well as negatives of photographs, are placed on it. After exposure to UV light, the uncovered or transparent areas react and turn Prussian blue while the covered area stays white. 

Pioneers

Cyanotype was invented in the nineteenth century by Sir John Herschel (1792-1871), son of William Herschel, the German musician who became an astronomer and single-handedly built the largest telescope ever. His son John experimented with light and managed to 'capture' ultraviolet light invisible to the human eye, leading, among other things, to the technique of cyanotype in 1842. He also came up with the word photography. But it was Anna Atkins, born in 1799 – the same birth year as 'fossil hunter' Mary Anning – who elevated cyanotype to an artform. She was the first to produce books illustrated with photographs, including: Photographs of British Algae: Cyanotype Impressions, showing beautiful prints of seaweeds. 

The fasciniation for marine algae was in full swing in the Nineteenth Century, and other nature lovers brought them to life through art. Adolf Schmidt (1812-1899) from Germany created an atlas with ethereal illustrations of diatoms with which he made an important contribution to science (Atlas der Diatomaceenunde, 1890). Driven by the same quest for beauty, biologist and artist Ernst Haeckel created unparallelled illustrations of nature, and especially of marine organisms (1834-1919), published in his Kunstformen der Natur.

Helena Cruz de Carvalho follows in the footsteps of these early pioneers, and using modern techniques, she has further expanded the horizons of cyanotype.

Chalk, corals and climate

Unlike diatoms and radiolarians, which are composed of silica, coccolithophores, and other organisms such as dinoflagellates and foraminifers are made up of chalk. Coccolithophores in particular are by far the most abundant chalk producing type of phytoplankton. And from this same material, lime of organic origin, arose the white marble that ended up in Michelangelo's hands and under his chisel.

Chalk (lime) is extremely sensitive to acidity. Acidic water dissolves the chalk, implying that if the pH of the ocean drops below a certain threshold, these algae – and more famously, coral reefs – disintegrate and can no longer exist. Since calcareous phytoplankton and especially coccolithophores are primary producers that regulate climate and are at the base of the oceanic food web, we humans would do well to avoid acidification. I can't think of a more urgent reason to reduce greenhouse gas emissions. 

Coccolithophores resemble little balls covered in calcareous plates. They have been so abundant that their limestone remains are the building units of thick rock layers. Among others, the famous chalk cliffs of the White Cliffs of Dover are made up of countless platelets of coccolithophores that once drifted along in the Tethys Ocean. Albion, as Britain was sometimes called, derives its name from the gleaming white of these cliffs, and unbeknownst to the namegivers, it is an homage to the calcite plates of coccolithophores — or are they the shields of Orion?

Art for the Earth?

As I ponder the cyanotype prints of these algae, I'm wondering which associations they evoke. Do they resemble toys for kids, musical instruments, pieces of jewelry, spaceships, microbes, or alien flowers? It is hard to tell. All I know is that they are at the core of what Stephen Jay Gould called 'wonderful life' and that our human existence is intertwined with theirs.

Helena's work not only shows the beauty of unknown unicellular creatures that are an integral part of this world and have been around millions, if not billions of years. And more than being a part of the world, they make the world we know it. Helena's work can help awaken a deeper collective consciousness. Just as artists in war have called for humanity through haunting paintings and music, this type of art can appeal to reason in times of climate crisis.

Where words fail, and scientific reports are being ignored, can beauty save us?

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Go to Helena's website: https://www.helenacruzdecarvalho.com/

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Because writing on climate and disasters sometimes disheartens, I prefer to focus on what is wonderful and fascinating, the things that give me energy. So read my article about the supercontinent Gondwana and the Snowball Earth, or about the latest solar eclipse and what it triggers in people, about amateur astronomy and how you don't have to be a specialist to understand the stars (there you will read about Wilhelm Herschel and his less known sister Caroline Herschel). My little moment with Jane Goodall was also hopeful, and in the article on the volcanoes of Europe you will discover a few hidden giants. Dwell on Carrara marble from Jurassic times and Michelangelo, phosphorus and the origin of life or the worlds of Narnia. Or check out my drawings, paintings, and other snippets of my mind on my other page.

Kathelijne: I am intrigued by how earth, life, air, ocean and societies interact on geological and human timescales.

Why I started GondwanaTalks.

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