Discover Importance of Marine Microbes

“Without microbes we couldn’t eat or breathe. Without us, they probably would be just fine.”

Would you believe marine microbes help you and I breathe easier? Would you believe that those same marine microbes have a hand in maintaining our planet’s stable climate that allows life to exist? And would you also believe that microbes account for more than 90% of ocean biomass and make up a hidden majority of the life that inhabits the sea? Hard to believe something so small can be so important ~ but it’s true.

Microbes carryout 3 fundamental functions

1. Photosynthesis
   Plant-like marine microbes (mostly phytoplankton and cyanobacteria) are estimated to provide more than 70% of the oxygen we need to breathe. The oceans have been called “earth’s last great forest” in reference to the huge influence these organisms have in the producing oxygen. Without them, you probably would not be reading this today. THANK YOU microbes!
2. Respiration
   All marine organisms including microbes give off carbon dioxide in the process of releasing energy (yes even plant – like organisms). There is a massive abundance of microbes in the world’s ocean, which tend to give off large amounts of carbon dioxide. This carbon dioxide is then absorbed and used by phytoplankton and other autotrophic organisms to perform photosynthesis. Of course, these organisms then release oxygen, which we and other organisms depend on to breathe. Once again, THANK YOU microbes!
3. Nutrient Recycling
   The neat thing about marine microbes, specifically bacteria, is the unique role they play in recycling nutrients and transferring energy within the marine food web. Microscopic bacteria are decomposers. They breakdown dead animals, plant matter, and organic wastes created by all living things in the ocean. If this were not happening, you would find yourself swimming with a lot of dead plant and animal remains. As you can imagine, it wouldn’t be a pretty sight!

Consider this:

How do you eat when there is no living organism smaller than you to prey upon?

Most microscopic bacteria are unable to photosynthesize, and they have no mouth to ingest food. Then how do microscopic bacteria get their food and energy?

Bacteria are able to consume some of the material they are decomposing. This material available only to bacteria as food is called dissolved organic matter (D.O.M.) and it originates from anything that was once living. Examples include the dissolved remains of dead organisms, excreted wastes from zooplankton (and larger organisms), the gelatin-like cytoplasm of single celled critters, sea slug secretions, and even blood…just to name a few!

Think of D.O.M. as a slice of pizza (or any other food) that has been put into a blender, with some water, and made into a pizza soup. It’s still pizza and has nutrients and energy, but instead of needing a mouth to eat it, now all you need is a method of absorbing it into your body. There are all kinds of D.O.M. floating around the ocean and bacteria take advantage by using it as a source of nutrition and energy.

Yuck maybe, but that “D.O.M. stuff” is really important. Carbon molecules are the essential building blocks of all life and Earth came with only a limited supply. Unfortunately, once carbon is converted into D.O.M. it can no longer be directly ingested by larger marine organisms and used as a source of energy.

So, what happens?

Bacteria are able to consume D.O.M. Then larger microscopic organisms called protozoans (such as flagellates and ciliates) consume the bacteria. The “unusable” carbon that had been floating aimlessly in the ocean depths is now recycled back into the marine ecosystem and the energy it contains is transferred up the traditional marine food chain to be used by larger organisms. Without the bacteria at the base, this energy would never make it back to the top. This cycling of matter and energy within the microscopic realm is referred to by scientists as the “microbial loop.”

Test your knowledge!

Take a quiz on the importance of microbes.