Coccolithophores: Earth's Little Helpers
Created | Updated May 13, 2005
There are many planets in this Galaxy. To the extent of our knowledge, Earth is the only planet out of the Milky Way, better yet - the Universe, on which life exists. Of course, having ventured into space for only a little over half a century, even our best knowledge can be flexible. As of yet, there has no real evidence that living things exist on other planets.
Why do living organisms exist on Earth and not on Mars or Venus? Why should Earth, an unstable geologically active planet that would often (and still is) shift and grind and erode and erupt along with the occasional rumbling of an unpredictable storm or whatever phenomenon perplexing enough to vex all the meteorologists and geologists around the world, have the honour to be the home of so many lives? Why not?
The Right Balance
Earth has the ideal gravity to hold on and develop an atmosphere that is light enough to hold oxygen, suitable for reflecting off most of the lethal rays and thick enough to burn off random meteoroids while still allowing enough heat and energy to seep through for necessary life processes like photosynthesis. For over three billion years the rather temperamental Planet Earth has somehow managed to maintain the right temperatures for life to exist, delicately balancing between the incoming rays and the one Earth had radiated back into space.
How could the same unstable planet keep from disrupting such equilibrium? Scientists had found that very answer and quite a lot of other answers when they stumbled upon the (mind-boggling) coccolithophore.
What are Coccolithophores?
Coccolithophores are marine dwelling phytoplanktons [tiny micro-organisms - cannot be seen with the naked eye - that live in the mixed1 layer of the sea and can be eaten by zooplankton and small fish]. They can grow in nutrient-poor conditions that other phytoplanktons cannot flourish in. Covering up to 1.4 million squared kilometres2 of ocean surface each year, coccolithophores have tremondous effects on both local and global environments.
Long-term Effects
One of the more conspicuous effect is the long-term/short-term relationship of coccolithophores with carbon dioxide and global warming. The Earth is undergoing global warming that mostly caused by greenhouse gases emissions trapping heat in the atmosphere. But has the world begun to prohibit breathing 3, pay the loggers to leave trees alone, passed laws to clean up the oceans, give full consent to the Kyoto Protocol? Why are there so much more of the greenhouse gases such as carbon dioxide and methane?
Our problem: Humans annually release over six billion tons of carbon dioxide by burning fossil fuels and other activities, yet the scientists had found only three billion tons in the atmosphere; one could only wonder what had happened to the other half, for three billion tons of carbon dioxide cannot simply disappear without a trace.
Solution: One coccolithophore is built up of numerous coccoliths, chalky plate-like carbonate. Coccoliths are made up of one part carbon, one part calcium and three parts oxygen; CaCO3.
Every time a molecule of coccolith is produced, one less carbon dioxide is floating around as a greenhouse gas. Coccolithophores also consume carbon dioxide by photosynthesis. The majority of the "vanished" carbon dioxides was sequestered by and converted to the cocolithophores.
Disguised Agents
Thus can coccolithophores counter global warming? Maybe.
Should scientists accelerate the growth of coccolithophores? Long-term wise, these phytoplanktons have already reduced tons of carbon dioxide by taking out the carbon to create the coccoliths.
Supporters of coccolithophores' population increase should be aware that the same formation of coccoliths that had reduced the amount of carbon in the air had also produced a carbon dioxide molecule from oxygen and carbon in the oceans. That molecule would most likely be used by coccolithophores, but some may escape back into the atmosphere.
It is possible in the short-term for the upper layers of the ocean to become more calm, increasing the population of coccolithophores, increasing the amount of gases escaping to the atmosphere. Right now, the statistics show a consistent decrease of carbon dioxide in the atmosphere (three billion tons). Coccolithophores use up a vast quantity of bicarbonate ions in the ocean as well.
DMS Cloud Formation Cycle
Another compound that coccolithophores can produce is dimethyl sulphide (DMS). Coccolithophores absorb sulphur compounds in the ocean and release DMS when cells die. The gaseous DMS undergoes chemical transformation in air and sea until it becomes a sulphate particle that condensed water vapor could use as a condensation nuclei to form clouds.
Basically, the more coccolithophores around, the more DMS gets released, and the more clouds are formed. The clouds meant more layers to block the Sun's rays and increase in precipitation and overall, a cooler Earth.
What is the problem here?
The Sun provides energy on which the plants are dependent. Plants often found in the upper and middle layer of the oceans also need the Sun's energy where the rays can penetrate. Coccolithophores are plants 4. If more clouds meant less sunlight could get through then photosynthesis cannot provide energy for everyone. If a living organism cannot get enough energy, it would die off.
Nature's Thermometor
Then there would be fewer coccolithophores left as there would not be energy for every coccolithophore to survive [competition]. Less DMS is released, less clouds made for want of condensation nuclei, the sun shines once more and lo, behold! In the oceans, the coccolithophores dwell once more in multitude... This DMS cloud formation cycle is repeated over and over again. This is how coccolithophores have helped Earth maintain stability in generally tolerable temperature for millions of years.
Other Effects
Coccolithophores have extremely interesting effects on their own environments as well. A peculiar effect caused by the coccolithophores is the increase in albedo, sunlight that an object reflects, and the changing of colors of the oceans that are the habitats of coccolithophores. Coccolithophores can now triple the amount of light reflected into space. This light scattering is how the water becomes a milky turquise color and also the origin of nicknames such as "fairy glow" and "white water". The waters beneath the oceans' surface, where the coccolithophores are, will become darker and may interfere with requirement of light necessary for the photosynthesis process of other organisms to take place. The massive scattering of lights had made it much easier for the "climatologists" to use satellites to detect and keep track of coccolithophore populations more accurately.
Active Helpers
Earth is an intricate interchanging stage interwoven with the acts and vital contribution formed from each diverse living (micro-)organism's functions in life. By simply existing and surviving, the coccolithophores had played an essential role in the lives of everyone on Earth (where else?). For what coccolithophores lacked in size, they more than made up in volume and the vast amount of atmospheric carbon dioxide that they consume annually, in addition to their role in producing DMS. One coccolithophore species, Emiliania huxleyi or E. huxleyi, alone can cover more than a hundred thousand squared kilometers of ocean surface and could produce an average of a hundred and six metric tons of CaCO3.
There are no small parts, only small actors.Never let it be said that size is relevant in importance. Coccolithophores are the prime example of this stereotype. Talk about such amazing impacts these small actors have dealt us!
-Alfred Hitchcock
1upper21 kilometre = 0.62 miles: for anyone interested in conversion, divide 1.4 million by the square root of 0.62... I'll get back to you on this3just kidding4algae
