Microplastics: A 'virus' to our Earth

Welcome to Suits & Tides, the sustainability blog with more knowledge than microplastics in the ocean. This week, we divert a bit from our usual business talk to zoom out on a broader issue affecting us all, businesses and individuals: how the microplastic 'virus' is slowly sneaking around us and Mother Earth and how it is affecting us in the long run.

Another pandemic about to happen?

Who would’ve thought that the whole world would fall into chaos a few years ago because of…a?small?virus? Well, it’s not the first time, and there will probably be another in the future. Didn’t mean to jinx it, of course. But actually, there’s already a ‘virus’ lurking in our midst right now, slowly eradicating our world. Just like organ systems in the human body, our Earth has a system that allows it to be ‘alive’. Or in this case,?it allows lives within Earth to exist because of a system known as the biogeochemical cycle.

The cycles of life

Biogeo–what now??Simply put, it is a circulation of essential matters through living and non-living things to support the functions of ecosystems. These processes are what make the Earth as it is now. One of the cycles you’re probably familiar with is the carbon cycle, which begins with the absorption of carbon dioxide from the atmosphere through photosynthesis by plants. Then animals consume those plants–transferring the carbon. When animals die, the carbon is released back into the environment through decomposition, and the cycle continues. Turns out, this cycle also happens in the ocean through the absorption of carbon dioxide by the phytoplankton–mediating roughly?half of the total global carbon cycle?despite their microscopic size due to their high abundance and diversity. That is insaneee!?Big things really come in small packages, huh?

The microplastic ‘infection’

We now recognise the importance of the ocean carbon cycle in regulating the Earth’s climate. But what if this global system could be disrupted by something… minuscule? We already know about the serious threat microplastics pose, including animal entanglement and potential human health risks. But that’s not all there is to it.?Just like a virus that can cause a pandemic, microplastics could affect the ocean carbon cycle and, ultimately, the entire planet. Microplastics may be insignificant in size, but their sheer quantity might have caused something, right?

Microplastics can wreak havoc on the ocean carbon cycle from the very beginning, which is the absorption of carbon from the atmosphere by affecting the growth and photosynthesis of phytoplankton. These tiny terrors can latch onto phytoplankton cells to hinder photosynthesis by obstructing light and airflow. They also promote the production of reactive oxygen species (ROS), chemicals that can damage other molecules. As if that weren’t enough, microplastic can reduce phytoplankton cell density and inhibit their growth rate. This adverse effect increases with decreasing microplastic particle size.?Whoa okay, we’re getting too sciency here. The intended message is that even though these studies may appear to have no impact on humans, you should be able to figure out the cascading effect. Imagine the foundations of a building. If the foundations are deteriorating, so will the whole building they support. Phytoplankton are producers in the aquatic food chain. So, the entire ecosystem could collapse if those phytoplankton can no longer sustain it.

The harm continues to the zooplankton that prey on those phytoplankton. Besides the apparent toxicity on their growth and life cycle, ingestion of microplastics by zooplankton physically obstructs their feeding behaviour and reduces their food intake. Organisms consume others to obtain energy and biological molecules necessary for their growth and functions, which includes carbon–the building block of life as it constitutes pretty much everything except water in an organism. When organisms consume less because of false satiety caused by microplastics, it means the carbon that gets transferred across living beings also decreases and impedes the carbon cycle. Even though zooplankton are microscopic, they play a significant role in carbon transport into the deep sea–a dark and cold place with scarce food sources because there’s no sunlight for photosynthesis. Many deep-sea organisms rely on the downward influx of the organic carbon synthesised on the ocean surface as their vital food source. This shower of organic matter is called ‘marine snow’, which consists of floating debris, decaying organisms, and faecal pellets.?Yes, poop. It may sound gross, but it is what actually allows lives to exist in the deep sea and the central part of the ocean carbon cycle.

So, what will happen next?

With less and less carbon absorbed and transported to the deep sea, it will lead to increased saturation of atmospheric carbon. And we all know what will happen when there’s an excessive amount of carbon in the atmosphere–climate change. The studies on microplastic warrant further research, but it starts showing evidence of the effect on the ocean carbon cycle.?The key point is that everything is interconnected. Our actions will have far-reaching consequences, whether directly or indirectly. Plastic–even something as small as microplastic–can alter the global system. Microplastics are still understudied, and that’s what makes them terrifying, no? Since we have yet to fully comprehend the consequences that microplastic can?actually?cause. It could be something more severe than what we currently understand. Just because something is yet to be understood doesn’t mean it is not happening.?Are we really going to venture into the unknown until we’ve reached the point of no return? Or will you join us–hand in hand to protect the ocean from plastic?

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