Microorganisms, Mega Power

There is a lot to think about these days when it comes to the oceans – numerous species overfished to the brink, polar bears threatened because of shrinking sea ice, whales still being hunted, sharks being finned alive. But as much as we care about animals we can see and understand, the vast majority of organisms in the oceans, and the ones that will ultimately control the fate of our planet, are microbes.

Microbes, or microorganisms, are any organisms too small to see with the naked eye, typically measured in millionths of a meter, or micrometers, hence the name. There can be hundreds of millions in every drop of seawater, and some microbes, called phytoplankton, grow in blooms so massive that they can be seen from space. Pictures like these reveal how the startling numbers of marine microbes can have profound effects on our planet.


Photo courtesy NASA’s Earth Observatory.

Ocean-going microbes come in many different types, differing into thousands of unique groups with specific roles. Phytoplankton constitute one large category of microbes, and function like single-celled plants, using sunlight and carbon dioxide from the atmosphere to grow. They form the base of the food chain, which supports all marine life, from other microbes to whales, and which is part of the larger carbon cycle vital to those of us who live on land because it affects our atmosphere and impacts climate change. Diatoms, a type of phytoplankton, manufacture beautiful and strange silica-based structures, and come in many fascinating varieties that can be observed with powerful electron microscopes.

Other types of microbes are important in the global cycles of ocean and atmospheric chemistry such as those concerning sulfur and nitrogen. Some interact with compounds that are far more strange and dangerous to ocean life, like oil, fertilizers and other pollutants that enter the ocean in urban and agricultural runoff. And just as their vast numbers make them the key players in the marine carbon cycle, so too do they play vital roles in these processes.

The many facets of these incredible tiny organisms and their myriad and powerful influences on the world’s oceans will be explored in more depth in the posts to come, so stay tuned!

Further reading:
Bradbury, J. Nature’s Nanotechnologists: Unveiling the Secrets of Diatoms. Plos Biol 2, e306 (2004).
Falkowski, P. Ocean Science: The power of plankton. Nature 483, S17–20 (2012).
Hazen, T. C. et al. Deep-Sea Oil Plume Enriches Indigenous Oil-Degrading Bacteria. Science 330, 204–208 (2010).


Cameron Thrash is a postdoctoral fellow working on marine bacterial genomics in the lab of Stephen J. Giovannoni at Oregon State University. He received his Ph.D. in Microbiology from UC Berkeley with a dissertation focused on bioremediation, using microorganisms to clean up contaminants, and has a B.S. in Biology from UC San Diego. In addition to his professional research on marine microbes, Cameron is an avid diver, surfer and general ocean enthusiast. More information on him can be found at http://jcammm.com.


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