Digested Digest: Phytoplankton

Posted 7 months ago in Food & Drink Features

Over 50% of the world’s oxygen is produced by plankton, with one out of every three breaths we take coming from ocean-based phytoplankton.

Phytoplankton are microorganisms that live in both salty and fresh water. There are three species: Diatoms (bacteria), Dinoflagellates (protists), and Desmids (single-celled plants). They provide nutrition for colonies of sea creatures, from whales to sea lions and dolphins, along with a vast array of fish throughout the globe. However, their role on this planet is not solely defined by their significance in the food chain, but by how they ensure that life continues as a whole. Like land plants, phytoplankton have chlorophyll to capture sunlight and they use photosynthesis to turn the sunlight into chemical energy. Just like trees, phytoplankton consume carbon dioxide and release oxygen into the atmosphere. All phytoplankton photosynthesise, but some get additional energy by consuming other organisms (when the diatom phytoplankton consume the desmid plankton). When the phytoplankton die, the carbon they have consumed throughout their lives sinks to the depths of the ocean along with their bodies. It’s this decay, spanning over millions of years that is partly responsible for our gas and oil reserves, trapped beneath the seabed. In case that’s not clear: Dead Plankton + Time = The world’s fossil fuels. Call me naive, but this absolutely BLEW MY MIND and further demonstrates how alienated from the sea we are as a culture. It might surprise you to hear that over 50% of the world’s oxygen is produced by plankton, with one out of every three breaths we take coming from ocean-based phytoplankton. Although this is not to detract from the role of trees in our ecosystem, phytoplankton are our planet’s unsung heroes.

Bioluminescent plankton

I had the idea of using phytoplankton on my menu when on holiday in West Cork this summer. Lough Hyne is a seawater lake and one of the most beautiful lakes in Ireland. It is Ireland’s first Marine Nature Reserve, steeped in folklore, castles, churches, and home to a unique ecosystem including bioluminescent phytoplankton. At night, the lake lights up into a spellbinding sea of shimmering bioluminescence, a defence mechanism caused by the chemical reaction in organisms containing luciferin, a light-emitting compound (lux is the Latin for light). Some organisms synthesise luciferin or generate it from consuming those who do. You can even go starlight kayaking in Lough Hyne from dusk to dark, where you can experience the bioluminescence firsthand. Seeing the phytoplankton reminded me of my time spent at three Michelin star, and avant-garde restaurant, Quique Dacosta in Alicante, as a young trainee exactly 10 years ago, when phytoplankton as a food source had just broken ground.

Phytoplankton as human food

I had spent six months of internship in the Valencian restaurant before I was asked to become Juanfra Valiente’s assistant. Juanfra was a decorated chef who spent three years in El Bulli, working alongside Ferran Adrià, the world’s best chef of his time. At Quique Dacosta, Juanfra was the head of the test kitchen and was responsible for the development of the intricate 24-course menus. I was in absolute awe of what went on in that space. With over 40 chefs, two menus, and serving both lunch and dinner six days a week, the restaurant was fast-paced, hot, and had no margin for error. However, in Juanfra’s room, next to the pastry kitchen separated by the glass door, everything changed. I recall knocking one day to ask if I could borrow a dehydrator. The door slid open and I was greeted by a welcoming blast of cool air and an immediate sense of serenity. The kitchen’s noise had dissolved and steel had been replaced by a calming brushed chrome and matt tile. Juanfra was standing by the island with a smile and showed me the dish he was creating: a phytoplankton focaccia with sea lettuce and smoked mozzarella. In Liguria, focaccia is made by pouring saltwater brine over raw dough, like it were a piece of meat. Typically, the purpose of a brine is to evenly season the ingredients throughout and not just on the outer surface. The dough is removed from the brine before cooking. In this case, Juanfra took inspiration from this tradition, using the saline qualities of the phytoplankton, massaging them into the dough and serving it topped with smoked creamy cheese and briny seaweed. Because phytoplankton had such extraordinary levels of chlorophyll, the focaccia became an appetising dark green. The result was an umami, sea-forward bite of pillowy heaven.

For Iceland, I took my learnings from Juanfra, and applied them to my potato bread recipe. We fermented the potatoes so that they become ‘cheesy’, kneading the bread with plankton paste, to impart a feint flavour of the sea and striking green colour inside. We served it alongside a condiment that looked like butter, but was, in fact, a spreadable soft cheese using Icelandic cream, milk, salt and a little lemon juice. Gisli asked me to say a few words prior to the dinner, and the story of this bread was the perfect opportunity to highlight our age-old baking traditions in Ireland, and indeed a new product like phytoplankton.

Health benefits

It’s not all that surprising to learn that phytoplankton are packed with vital vitamins, sea minerals, amino acids, and bioavailable omegas. After all, small fish feed almost exclusively on this species, and we are all aware of the benefits of eating fish! Phytoplankton contain the highest levels of B12 vitamins of any other vegetable-based ingredient. B12, is typically sourced through animal proteins, and it is a common issue amongst people with vegetarian and vegan diets to be B12 deficient. Plankton is known to protect the skin from UV, reduce the chances of oxidative stress, and reduce premature skin aging

Warming of the ocean

“A warming ocean creates conditions similar to growing food on barren land, meaning productivity would be extremely low.” – Harshid Podder

There are a billion billion billion phytoplankton on this planet. Each measuring one micron (1000th of a mm). However, their number is dramatically decreasing. If they were to disappear, the whole marine ecosystem would disappear. The result? Our very own disappearance. No plankton means no fish, no local trade and economic collapse. As the climate warms, phytoplankton (which all favour cold water) are at grave risk of collapse. According to NASA, a warming ocean reduces the mixing between surface water and deeper, nutrient-rich water in the oceans. This reduces the nutrients available near the surface.

You might be thinking that if phytoplankton are so important to our survival, why suggest eating them? Although wild species can be foraged and harvested, this is not advised. Specific species of phytoplankton are also cultured at labs like Fitoplancton Marino in El Puerto de Santa María. As reported by Fast Company, “It’s not like you can go to the oceans and go, ‘Let’s harvest it and eat it’ ”, says Carlos Unamunzaga, the lab’s general manager. “Even if it was possible to harvest from the wild, you don’t want to deplete the ocean or a marsh.”

The company inoculates and raises phytoplankton in a closed system that’s been designed to replicate the natural environment. Unlike the aquaculture industry, which feeds their farmed fish with wild fish (something that makes no sense at all), the only ingredients used at Fitoplancton Marino are CO2, seawater and sunlight. To source my plankton for Iceland, I had to get in touch directly with Plancton Marino.

Food for thought: Phytoplankton don’t taste like fish. Because the food for fish is sourced entirely from these microorganisms, instead, fish taste like phytoplankton.

Cúán Greene is a chef and author of the Ómós Digest Newsletter which expounds upon topics relevant to food culture, sharing insights, positing questions and meeting people who are adding to the collective pot. Each month, we share an edited highlights from recent posts. To sign up for a more comprehensive deep-dive, visit omos.co

Words: Cúán Greene


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