The future of the phytoplankton, and why it’s important to us

The phytoplankton. A nerdish word that doesn’t ring any bell, except maybe for biologists, oceanologists, climate researchers, or other species of scientists or science enthusiasts.

In fact, it’s kind of weird that it is so overlooked, and here’s why: it’s a little-known yet mind-blowing fact that more than 50% of the oxygen we breathe is created by organisms living in the oceans, collectively called the phytoplankton. Most of those organisms, in healthy concentrations, are invisible to the naked eye, making it hard to connect with them without a microscope.

But even a teaspoon of seawater can contain more than a million creatures. All life in the ocean depends on these microorganisms, as they are at the base of the food chain. And we, creatures of the land, rely on them too. Not only because we might run out of fish if we continue living like this but also because we might “run out” of many other things because of our unsustainable lifestyles impacting the ecosystem.

Those overlooked microscopic beings have a major role in regulating the planet’s climate, having the power to reshape the atmosphere, but as other powerful things, not appropriately treated they develop their dark side, unleashing pure horror on the environment. This article serves as a glimpse into what is happening.

What’s the phytoplankton?

The phytoplankton makes up part of the larger plankton. The name derives from the greek phyton, meaning ‘plant’ and planktos, meaning ‘wanderer’ or ‘drifter,’ pointing out the fact that the organisms of the plankton found in water or air are unable to move on their own. Phytoplankton is a big category of all the water creatures that produce oxygen through photosynthesis. They live in zones with sunlight in oceans and lakes, self-feeding.

The phytoplankton comprises all kinds of different organisms with difficult-to-spell names, like cyanobacteria, diatoms, dinoflagellates, or coccolithophores. Let’s grant some of them a short presentation:

Cyanobacteria

They started it all. A long, long time ago, they evolved and started pumping oxygen into the atmosphere, so they are the very reason we actually exist at all. It sounds like a mythological story, but they are the ones who made the sky blue if you were ever wondering who’s to blame for that.

Dinoflagellates

Dinoflagellates are usually considered to be algae. Unlike other drifters, they can move a little bit around, with the two whips (flagella) their names stand for. They are bioluminescent, meaning they can produce their own light, which can be really beautiful. Their overpopulation can cause a harmful, toxic algal bloom.

Diatoms

Diatoms are algae that build a beautiful silica armor around themselves. They come in a fascinating variety of science-fiction shapes and forms. When they die, the shells remain fossilized, still contributing to life mixed in earth as the food for plants in your garden. (Diatomaceous earth contains fossilized diatoms). They take in 6.7 billion metric tons of silicon from the waters annually. The shells of dead diatoms in the ocean floors can reach a half mile in depth.

Coccolithophores

Coccolithophores look like a bunch of discs stuck together in the shape of a ball. Shells are made of calcium carbonate. England’s famous White Cliffs of Dover is made up of fossilized remains of many coccolithophores.

Balancers of the climate

The magnitude of the importance of phytoplankton is explained by the fact, that they can control atmospheric carbon dioxide concentrations. The microorganisms of the phytoplankton can fix some of the carbon dioxide through photosynthesis. Capturing the carbon from the atmosphere, they help regulate the climate of the planet.

Even the beloved smell of the sea is created in fact by compounds of phytoplankton, and some compounds can travel up into the atmosphere and help in the forming of clouds.

But what’s really mind-blowing is, that they consume as much carbon dioxide as all of the earth’s forests and plants combined, producing roughly 50% of the oxygen on the planet. Statistically, they pull 11 gigatons of carbon from the atmosphere per year, even though their total mass is 450 times smaller than that of the total plant mass on earth.

A short history of the air we breathe

As I wrote earlier, cyanobacteria are the reason we have oxygen in the atmosphere in the first place. 2.5 billion years ago, cyanobacteria evolved and started pushing oxygen into the air, turning the once-green waters and orange skies blue (The Great Oxidation Event), creating the conditions for the evolution of complex life.

Out of uncertain causes, phytoplankton did this again 540 million years ago, bringing up the oxygen concentrations in the air, making it possible for life to spread, on the land, too. Since then, they have had a balancing function in ocean chemistry and according to paleontologists, they helped to protect sea life from mass extinctions ever since. They used to balance out the sudden ph shifts volcano eruptions used to produce, for example.

Their shells accumulate in the seabed, forming a calcium carbonate layer that serves as a balancer of the acidity of the water. Today, this chalk layer in the ocean beds helps to balance the acidifying effects of all the co2 we are pumping into the atmosphere. At a more neutral ph, the shells are solid, but in contact with acidity, they start to dissolve, releasing carbonate ions, that contribute to restoring optimal ph.

The impact of human activity

There are odes to be sung about the awesomeness of the phytoplankton and algae when they can function in balance. But unfortunately, human activity has disrupted their normal behavior, and we must discuss this, too. Let’s take, for example, the Gulf of Mexico. Sadly enough, we could examine many other similar cases too. There’s this phenomenon in the gulf that every year, from may to autumn, the buzzing sea life seizes to exist, with all animals and critters fleeing the area or dying. Creatures that can’t swim or flee fast enough die of suffocation. Thousands of kilometers along the coast have become marine dead zones, and this is just one of many similar affected areas around the globe.

The problem with chemicals

The problem is that apart from the sunlight for photosynthesis, algae depend on phosphorus and nitrogen for growth. While a smaller amount is necessary for their survival, a more considerable amount of these can lead to dangerous overgrowth, blocking sunlight from the plants on the seabed, on which other life, like fish, depend.

What’s happening in the Gulf of Mexico and all the dead zones around the world? Why do the algae overpopulate, creating deadly imbalance instead of balance? The answer is in the high concentration of chemicals rivers bring to the oceans from the land. All that excessive nitrogen and phosphorus comes mainly from the fertilizers we use for growing crops. Their effect is the same on algae: they start to grow.

Emissions and climate change as contributors

Dangerous overgrowths – called algal blooms – thrive, not only because of all the chemicals but because climate change is assisting their growth too: the warmer waters and hotter, wetter summers help them spread in all kinds of waters.

Some algal blooms can become harmful health hazards, producing toxins like cyanotoxins, microcystin, or anatoxin-a, which can harm plants, animals, and even humans by consuming fish or shrimp with high concentrations of those toxins or being exposed to them some other way, like swimming. Algae toxins can cause allergic reactions and, in some cases, death.

And while the phytoplankton is a carbon fixing machine, there’s only so much it can do, dealing with all the CO2 in the air, too.

In conclusion

The phytoplankton is an ancient, tough and adaptable thing that radically changed the atmosphere once, initiating the evolution of complex life on earth. As small as they are, they deserve our most profound respect. Sustainable living is essential for their – and our – well-being. Their future depends on our actions, but remember that they have the power to turn all our poison back at us, restoring balance. After all, they are mythological heroes.