Phytoplankton Facts: An Opportunity To Dive Into The Ocean

Joan Agie
Nov 03, 2023 By Joan Agie
Originally Published on Mar 25, 2022
Find out interesting Phytoplankton Facts here.

Phytoplankton are basic components needed for the sustenance of the world!

You may be surprised, but this is the truth. These humble microscopic organisms are primary producers in the water and help balance the complex food web that runs through the world.

Phytoplankton is a group of microscopic organisms, including bacteria and protists, that are found on the ocean surface. They are also found in other water bodies. The name phytoplankton is derived from two words phyto, meaning plant, and plankton, meaning drifting or wandering.

These function just like land plants. There are so many types of phytoplankton species in the ocean surfaces, including bacteria that photosynthesize to plant-like algae. Did you know that there are more than 5000 types of phytoplankton in the marine environment? The numbers could be even more. Scientifically, all photoautotrophic microorganisms in the aquatic food web are called phytoplankton.

They use sunlight and convert light energy into chemical energy using a process called photosynthesis. Photosynthesis is a very important reason why the Earth has survived for so long. Creatures that can perform photosynthesis are called photoautotrophs. Every living being in the world needs oxygen to survive, and photosynthesis is one reason why the Earth consistently receives enough oxygen.

These photoautotrophs convert light and carbon dioxide in the atmosphere into oxygen and organic material. Plankton is the source of food for most of the zooplankton in the ocean.

These are also called heterotrophic plankton and are tiny animals that feed on phytoplankton and, in turn, become primary food sources for bigger species. Most of these organisms are invisible to the naked eye. However, some variants like the jellyfish are larger.

In marine life, everything would come to a standstill without phytoplankton. Do not worry, though. There is no dearth of these microorganisms on ocean surfaces. Studies show that there may be up to 500,000 billion tons of these spread across all ocean surfaces.

Types Of Phytoplankton

There are different types of phytoplankton, depending on their structure and size. Some of the common ones include cyanobacteria, green algae, dinoflagellate, diatom, and coccolithophore. Out of all these, diatoms and dinoflagellates are the most commonly found variants.

Diatoms: These algae are single-celled and have chloroplasts. Diatoms are capable of undergoing photosynthesis, and across the world, diatoms produce 20-50% of all the oxygen produced. These unicellular variants are present in the water bodies in the shapes of ribbons, fans, stars, and zigzags. The lifespan of these algae is a maximum of six days.

Dinoflagellates: These are very similar in type to diatoms, but the only difference is that these have a whip-like tail which is called the flagella. As of now, 2294 variants of dinoflagellates have been identified in the world.

Experts believe that there may be many more variants still unidentified. These algae can produce light and create something called bioluminescence. As a result, some oceans, when they are full of these organisms, may have a blue-green light to them and glow in darkness!

Cyanobacteria: This is also called blue-green algae and is a type of bacteria that is found in almost all water bodies. Did you know that when the earth was struggling to survive in the early periods, cyanobacteria were the first organisms to produce oxygen and lead to the growth of other species?

In fact, these formed the basis of the development of photosynthetic capacities in plant cells.

Coccolithophore: A coccolithophore is a single-celled alga and is one of the largest producers in the marine food web. These creatures are very important in determining climate change as they contribute to a carbon sink, a condition that leads to excess accumulation of carbon in the ocean bed.

Ecology Of Phytoplankton

Phytoplankton, like most land plants, uses sunlight to go through photosynthesis, and the basic need for the growth of this aquatic food is the location. It needs to be in a place that has ample sunlight. You may be surprised, but these organisms are responsible for almost 50% of photosynthesis in the world.

Apart from sunlight, phytoplankton also requires nutrients to grow. These nutrients reach the ocean surface through different sources. Some of the major sources needed are nitrates, phosphate acids, and vitamin B. Lack of these nutrients can lead to the destruction of existing plankton and the slow growth of new ones.

Since phytoplankton is a basic food source, it is consumed regularly by small creatures, heterotrophic planktons, and other organisms in the ocean.

Once phytoplankton dies, it decomposes and becomes nutrients that fill up the ocean bed. It is interesting to note that once phytoplankton dies, it is decomposed by other groups of microorganisms: bacteria and viruses in the ocean.

One of the main uses of phytoplankton, making it ecologically very important, is its ability to recycle the contents in the ocean.

Phytoplankton is a group of microscopic organisms

Uses Of Phytoplankton

Apart from being primary food sources for ocean organisms, phytoplankton populations are very important for the below reasons. Phytoplankton is the only source of food for herbivores zooplankton, and if these species do not survive, the bigger species do not. As a result, phytoplankton growth may be indirectly responsible for marine biodiversity.

Phytoplankton provides phosphorus to zooplankton which they cannot get through other sources. Experts are of the opinion that zooplankton cannot reproduce without phosphorus.

Another very interesting use of phytoplankton is to ensure the higher species get the right biomolecules, including fatty acids, amino acids, and sterols, which are sent from phytoplankton to zooplankton organisms. When the animals in the higher end of the food chain eat these organisms, they receive the biomolecules.

Climate Change And Phytoplankton

You may think, how do invisible microorganisms play a role in climatic changes. The answer is very interesting!

Phytoplankton play a major role in sending carbon dioxide from the atmosphere into the ocean. As discussed above, these algae use carbon dioxide in their photosynthesis process. Now the carbon is stored in the bodies of these planktons. Once they perish and decompose, the carbon falls to the ocean's depth.

This carbon dioxide recycling and the dumping of carbon into the ocean bed is called a biological carbon dump. Studies say that these organisms transfer up to 10 gigatons of carbon this way from the atmosphere into the ocean.

This carbon cycle happens seamlessly every single day. However, if there is even a slight increase or decrease in phytoplankton growth in one area, then the atmospheric carbon dioxide levels will vary, causing global climatic changes.

In some areas, when the conditions are all right, there may be a sudden boom of phytoplankton growth, leading to a massive increase in the levels of this organic material. This condition is called a bloom.

Blooms may last for a few days or a few weeks and can even be spotted on satellite images.

Dense growth or a sudden increase in phytoplankton levels in an area can deplete oxygen levels and lead to severe consequences. That's why researchers are always on the lookout for abnormal increases in phytoplankton rates throughout the world.

It is also said that these organisms are responsible for the formation of clouds and increase or decrease in temperature.

Scientists are these days able to predict climate changes clearly by examining the changes in plankton levels in the water bodies.

When it comes to the food web, phytoplankton ensures no ocean life goes extinct without food or nutrients. This helps preserve fisheries.

It is very clear that phytoplankton deserves a lot more interest than it has been given so far. Most people are not even aware of this wonderful source of nutrition that is the base for all marine organisms.

The food web starts from phytoplankton and ends with human beings consuming seafood. Since phytoplankton photosynthesis and growth play such an important role in climate changes and ocean biology, it is very important to constantly keep a check on their levels from time to time.

According to experts, the global phytoplankton count has reduced in the last 100 years. Preserving the environment, avoiding overfishing, and preventing pollution of water bodies are all ways we can help preserve the phytoplankton diversity.


What is phytoplankton, and why is it important?

Phytoplankton is a group of organisms that range from photosynthetic bacteria to algae that act as primary producers in the ocean.

Plankton serve as food for tiny animals in the ocean, which in turn become food for the larger variants of fish and other ocean creatures. Plankton also plays a role in distributing organic material like micronutrients and biomolecules across the ocean, ensuring the larger variants are able to survive.

For mankind, phytoplankton is important because it absorbs carbon dioxide from the atmosphere and sends out oxygen, just like land plants.

How much phytoplankton is in the ocean?

This is one of the Phytoplankton Facts that you will be amazed to learn about. There are more than 500,000 billion tons of phytoplankton in the oceans across the world right now. When their development is not hindered by environmental and human factors, they are produced in the right amounts, helping in oxygen creation in the ocean and atmosphere.

What is phytoplankton used for?

Phytoplankton is the only source of food for certain herbivore zooplankton variants. These organisms, in turn, are consumed in large quantities by small fish and other ocean creatures, which in turn, become prey for larger animals.

Phytoplankton is hence a basic necessity to keep up the ocean food web. It is also good for the environment for producing oxygen and removing carbon dioxide.

Is phytoplankton the same as spirulina?

Spirulina is one of the latest interests in the health industry and is being advocated as a healthy supplement. Yes. Spirulina is one of the types of phytoplankton and belongs to the cyanobacteria category. However, it is grown in freshwater and is not found in marine waters like most phytoplankton types.

Can dogs eat phytoplankton?

Nutritional experts say that dogs can eat phytoplankton safely. In fact, it is one of the most nutritious and balanced supplements for dogs and will keep them healthy and strong. Since most dogs have trace mineral deficiency, these supplements can help match that.

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Written by Joan Agie

Bachelor of Science specializing in Human Anatomy

Joan Agie picture

Joan AgieBachelor of Science specializing in Human Anatomy

With 3+ years of research and content writing experience across several niches, especially on education, technology, and business topics. Joan holds a Bachelor’s degree in Human Anatomy from the Federal University of Technology, Akure, Nigeria, and has worked as a researcher and writer for organizations across Nigeria, the US, the UK, and Germany. Joan enjoys meditation, watching movies, and learning new languages in her free time.

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