Our Tiny Companions: The wonderful world of microscopic organisms

If you are reading this, you probably know the importance of prides of lions in controlling herbivore populations in the African savanna, the crucial fertilizing function carried out by large whales in the oceans or even the “maintenance” of coral reefs by sea turtles.

At the same time, it is also very likely that you have never seen a whale, or that you have not been within 5,000 km of a pride of lions in the wild, and yet you are aware of their importance, of their fundamental role in maintaining global ecosystems. You are aware of all this thanks to the work of committed people, who dedicate their lives to showing all of us who “can't see a lion up close” that said lion matters, who feel that it is worth fighting for the conservation of our fellow planet companions.

But, what if I told you that we have other companions, much smaller, much more unknown, present in all the ecosystems of the planet, directly responsible for the existence of lions, whales and turtles... and that most of us have not seen either, despite how close we are to them...

Let me introduce you to the wonderful and unknown world of microscopic organisms.

Marine dinoflagellates. Noctiluca sp

microalgae Closterium sp

Marine dinoflagellates. Noctiluca sp. (left) and microalgae Closterium sp. (right).

What are microscopic organisms?

When I talk about microscopic organisms I am referring to all living beings that we cannot see with the naked eye; bacteria, fungi, protozoa, nematodes and much more, since, although it may sound surprising, they constitute 90% of the planet's biodiversity. Under this name I include organisms made up of a single cell, such as bacteria, protozoa or microalgae, to multicellular organisms such as rotifers, tardigrades, water fleas or even many larval stages of animals that in their adult state we can see with the naked eye.

They are responsible for the recycling of matter and energy in the biosphere, they control biogeochemical cycles, they are the main CO2 fixers...

In fact, all living beings depend, in one way or another, on the activity of microscopic organisms.

Water flea. Ceriodaphnia sp.

The air we breathe

We all need oxygen to breathe (or almost all of us). It is estimated that approximately 30% of the oxygen we breathe is a direct product of photosynthesis carried out by trees and plants, but what happens to the remaining 70%? To discover it we must not look on land through binoculars, but in the water and through a microscope.

Cyanobacteria, diatoms, dinoflagellates, microalgae... an endless number of tiny beings, almost invisible to the naked eye, are responsible. All of them constitute what we know as phytoplankton and not only contribute substantially to the production of oxygen, but act as the basis of the trophic chains of all aquatic ecosystems and even directly affect the regulation of the planetary climate (they are largely responsible for the formation of clouds over the ocean).

The water we drink

As far as we know, there is no life without water. Seas, oceans, lakes and rivers constitute complex ecosystems with very delicate balances. Without the presence of organisms such as ciliated protozoa, rotifers or amoebas, the populations of bacteria present in the water would not have their main natural regulators, so these ecosystems would no longer be a suitable environment for the development of other forms of life and a reliable source of drinking water. Its activity is so efficient that we have even copied that system and adapted it to our water purification plants.

Marine nematodes.

The land we eat from

Most of the food we consume depends directly or indirectly on the activity of microscopic organisms in the soil. Bacteria, fungi, nematodes, springtails... are the main people responsible for soil health. They facilitate the penetration of water, allow oxygenation, decompose organic matter and release nutrients that are then used by the plants on which all terrestrial organisms feed directly or indirectly.

Without their activity, the ground would be nothing more than a sterile and uninhabitable surface.

A personal beginning

My fascination with the natural world began very early. By the age of eight, I had already watched every single National Geographic documentary in our home. I used to go into the woods to watch birds, deer, and wild boars, proudly saying that when I grew up, I wanted to be a biologist. I was, so to speak, the odd kid who was into bugs.

Life took my studies in a very different direction, but my love for nature never faded. We had a microscope at home, and yet, somewhat shamefully, I didn’t really use it until after finishing university.

From that first day, though, everything changed: I discovered an entire universe of shapes, colors, and movements that I had never imagined.

I discovered that a single drop of puddle water could contain entire ecosystems, that some animals are so incredibly small they could slip with ease through the eye of a needle. I learned that the gut of a termite is home to countless tiny symbionts that look like spaceships, and that there are creatures capable of reproducing both sexually and asexually at once...

It was impossible to keep it to myself. That’s how I started taking my first (very bad) photomicrographs and videos through the microscope. I still have countless hard drives filled with my earliest images and videos (more valuable to me for their memories than for their professional or aesthetic quality) now gathering dust in some forgotten corner of my studio.

What began as a hobby soon became a passion and, little by little, a central part of my professional life.

Why don't we see them?

Let me now get a little more personal. The incredible importance that these microscopic beings have for the maintenance of all life on the planet seems undeniable, and yet why don't we see them? I am not referring to the technical difficulties of observing them directly, but to the fact that such relevant actors in the planetary ecosystem do not have a presence (or barely have one) in the media, platforms, television or magazines dedicated to environmental conservation.

It was these facts, having them so close and not seeing them, that they are so important and that no one shows them to you, that convinced my father Rubén Duro to incorporate the microscopic world into the traditional nature documentary, and it was him who showed me that new universe that no one else had shown me.

Since then I have dedicated myself to investigating this wonderful microworld and trying to convey my passion for it through video and photography.

I am sure that the day will come when the lion and the tardigrade, the whale and Stentor have the same level of recognition, in which the conservation of ecosystems is advocated taking into account these tiny but essential protagonists. And I like to think that I am doing my bit so that day is ever closer.

Protozoan ciliate. Paramecium sp.

A safari from home

If something I have told has managed to awaken your curiosity about these tiny beings, here is a short video that I made a few years ago with the intention of showing the diversity and beauty that we can find in a mountain stream.