When one thinks of the oxygen in our atmosphere, the most likely considered sources are trees, right? In reality, marine plants produce 70-80 percent of the oxygen found in our atmosphere, through photosynthesis. One of the most fascinating creatures found in our bodies of water plays the lead role in this production: Diatoms. Diatoms supply the oxygen in half of the breaths a person takes in their lifetime. Through photosynthesis, they harness the sun’s energy, and carbon is fixated to self-produce food for survival. The oxygen we breath is a by product of this process, carried out by trillions upon trillions of diatoms in rivers, lakes, and oceans. But their contributions do not stop there. These magnificent organisms have stayed around for hundreds of millions of years, and have immersed themselves in the production of almost 100 percent of the Earth’s oxygen. Their contribution and presence extends far beyond the ocean surface. First, we have to understand their history and ecological relevance.
The oldest confirmed diatom fossils are from the cretaceous age, but evidence shows that fossils resembling diatoms, or diatom relatives, go back to the Triassic period (200 million years ago). This early appearance has led to a very diverse group of single-celled diatoms to multi-cellular colonies, as presented.
They are characterized as frustules, as being unicellular with a silica-based cell. Frustules are broken into two halves, which allows for easy cell division into two daughter cells. The diatom population is one of the most radical boom-bust populations on the planet, and can be characterized as “r” grouped organisms. The diatom population doubles every day after a feeding frenzy from a fallen glacier. These glaciers, most commonly in Svalbard, Norway, hold a powdery substance with certain bacteria. This is another food source for diatoms, but sometimes, these glaciers only fall once or twice per decade. This causes massive population swings, as commonly seen with r-selected species. However, when they die, they become part of the diatomaceous earth, which is a layer on the ocean floor that has been found to be 50 yards deep. Their carcasses benefit our world in a completely different, but nourishing way.
Tectonic plates shifted the bodies of land we know today. Certain parts, like the desert of Danakil in East Africa, are exposed surfaces of what was once the ocean floor. Millions of layers of diatom carcasses have exposed themselves to the world, and they help something across the Atlantic Ocean thrive: The Amazon Rainforest. Dust storms carry the nutrient-rich sediment from the desert across the ocean, and the rainforest is fertilized with pure resources. This helps the Amazon produce the other 20 percent of the oxygen for our planet. So, in essence, these unicellular organisms have provided the world with precious oxygen for millions of years in every way possible.
For an organism four times thinner than a human hair, an impact such as this is remarkable. Diatoms are living proof that one system of the Earth is connected to another, on the opposite side of the planet. Whether they are dead or alive, they will be keeping bigger and stronger organisms alive for millions of years to come.