No icy flakes underwater, but an equally magical phenomenon! Marine snow is a ballet of tiny particles formed from the remains of organisms and excrement, in which bacteria and plankton thrive. It’s a veritable microscopic world that comes together to form millimetre-sized flakes… which fall inexorably towards the abyss. A real feast for the inhabitants of the deep! 🐟

👉 Plant plankton is at the heart of this cycle: it captures CO₂ at the surface and, once dead, forms a large part of this ‘snow’. The undigested organic matter during its fall finally joins the sediments of the seabed, storing carbon for millions of years. Oceanic plankton is thus at the heart of the regulation of the world’s atmospheric climate. This phenomenon helps to absorb almost 30% of man-made carbon dioxide emissions!

🔴 But our activities are threatening this natural cycle.

Direct overfishing of planktonic species, particularly krill for its oil, is drastically reducing the quantities of plankton. Marine pollution, such as plastics and heavy metals, further complicates the situation. These pollutants reduce the size of plankton and impair their ability to carry out their vital functions, thereby affecting the ocean’s carbon cycle.

🌡️Global warming is also jeopardising this vital mechanism. Changes in plankton populations caused by rising temperatures are altering the diversity of plankton, potentially disrupting the formation of marine snow, reducing its effectiveness in feeding the deep sea and storing carbon.

🎄 In this festive season, let’s think about preserving this incredible underwater world, the guarantor of our climate balance. 💙

Thanks to the MICROCEAN project team and their colleague Melvak for this video 🙏 As part of this project, Pauline Le coq is studying this magical phenomenon to decipher its mysteries ❄️