Discovered in 1977 during a research expedition in the Arabian Sea, Synechococcus (and later Prochlorococcus in the Sargasso Sea) are two species of cyanobacteria that collectively, are the most abundant organisms on earth (Waterbury, 2005). These photosynthetic picoplankton grow no larger than 2 micrometers, yet despite their seemingly insignificant stature, play an essential role in the majority of primary productivity that takes place in the oceans.
One of the important roles that they play has to do with the carbon cycle, which they influence by harnessing energy from the sun and turning it into organic matter via photosynthesis. Because these picoplankton occupy the lowest level of the food chain, they are vital for all subsequent consumers to exist (including the Ahi that we love to eat here in Hawaii!). Another essential role that cyanophytes play is in nitrogen fixation, or the reduction of dinitrogen obtained from the atmosphere into ammonium. Its ability to fixate nitrogen through specialized structures called heterocysts, allows the bacteria to flourish in nutrient depleted water, and provide nitrogen to organisms that consume it (Zehr, 1996).
Clearly, cyanophytes play an integral role in our oceans. Alas, had they not had the misfortune of being named Synechococcus and Prochlorococcus, but instead, “Superalgae” or “Superbacteria,” they would have already been household names today, and gotten the true recognition that they deserve.
- Grant B.
Waterbury, J. (2004). Little things matter a lot. Oceanus Magazine, 43(2).
Zehr, J. P., & Capone, D. G. (1996). Problems and promises of assaying the genetic potential for nitrogen fixation in the marine environment. Microbial Ecology, 32(3), 263-281.