Plankton is important for the ocean as it forms the basis of the marine food chain, providing food for many marine species, from tiny fish to whales. Additionally, plankton plays an active role in regulating the climate by absorbing carbon dioxide from the atmosphere and producing oxygen during photosynthesis.
Plankton is essentially the basic food source for a huge part of marine life. Just imagine: it all starts with these tiny plant organisms, phytoplankton. They capture the sun's energy to grow and multiply. Then come the little creatures called zooplankton that feast on this phytoplankton. Behind all this, fish, shrimp, whales, and other larger marine animals completely depend on this little world as their main pantry. In short, without this plankton, the entire marine food chain would quickly collapse.
Phytoplankton does much more than gently float on the surface of the oceans: these tiny microscopic organisms produce about half of the oxygen we breathe every day. Instead of using leaves like land plants, they absorb CO₂ and use the sun's energy to release oxygen through photosynthesis. Without these tiny floating beings, the air we breathe would be considerably less rich. Think about it: with every second breath, it's a little thanks to them. Not bad for almost invisible microorganisms, right?
Plankton helps to naturally regulate the carbon cycle in the ocean. It acts a bit like a miniature CO₂ vacuum cleaner. Through photosynthesis, phytoplankton consumes the carbon dioxide present in the water. It then fixes it in the form of organic matter, thus serving as food for the entire marine ecosystem. When it dies, some of this plankton sinks to the ocean floor, carrying with it a reserve of carbon that can remain trapped for centuries. This is called the biological carbon pump: a super discreet, yet highly effective way to permanently remove some atmospheric carbon to the ocean depths. Without this little daily job, carbon levels in the atmosphere would rise even faster and worsen the greenhouse effect. In short, thanks to plankton, the ocean plays a key role in combating climate change.
Plankton acts as the true pantry of the ocean. Phytoplankton is consumed by small marine animals, zooplankton. These, in turn, feed fish, whales, and crustaceans at will. Without them, the entire marine food chain collapses. When plankton populations move, it directly influences the movement of fish. It's no wonder that fishermen closely monitor these small aquatic creatures to locate fish-rich areas. Proper regulation of plankton thus ensures a sustainable abundance of marine food resources.
Observing plankton is a handy trick for monitoring the overall health of the oceans, similar to taking a person's pulse to see if everything is functioning well. When plankton is abundant and diverse, it indicates that the ocean is in good shape. Conversely, a sudden reduction or strange changes in its development can reveal that there is an issue: pollution, climate change, or excessive acidification. It is therefore an excellent tool for easily and broadly understanding how the marine ecosystem responds to various ecological stresses.
Some phytoplankton blooms can be seen from space; they color the oceans green, blue, or even red, indicating regions rich in nutrients and significantly influencing local fisheries.
Some zooplankton organisms, such as krill, perform vertical migrations in the ocean every day, moving up to several hundred meters; this is one of the most massive and regular migrations in the world!
Blue whales, the largest animals living on Earth, feed almost exclusively on plankton. An adult blue whale can consume up to 4 tons of krill per day.
Bioluminescence visible at night on beaches or when a boat cuts through the waves is often produced by planktonic organisms called dinoflagellates. This light emission is a defense mechanism against their predators.
Although rarely consumed directly by humans due to its tiny size, plankton is sometimes used in dried form as a protein- and vitamin-rich dietary supplement. However, its main role for humans is indirect, as it serves as the essential foundation for the survival of many fish and seafood that we consume.
Most of the time, plankton is microscopic and unnoticed by the naked eye. However, some species of plankton, such as large jellyfish or certain bioluminescent organisms that create visible flashes of light, can be observed without any special instruments.
Human activities such as chemical pollution, plastic waste in the oceans, overfishing, and climate change can significantly disrupt plankton populations, leading to the disappearance of sensitive species and reducing their ability to fulfill their vital ecological functions.
Plankton, and particularly phytoplankton, plays a major role in capturing atmospheric carbon dioxide and thus contributes to regulating the global climate. Changes in their population and distribution can therefore exacerbate the effects of climate change by reducing their ability to absorb CO₂.
A complete disappearance of plankton is unlikely, but its decline is possible due to climate change, ocean acidification, and various forms of pollution. Such a decline would have catastrophic effects by disrupting marine food chains and global climatic cycles.
0% of respondents passed this quiz completely!
Question 1/5