Despite what SpongeBob Squarepants may lead you to believe, not all plankton are inherently evil, greedy creatures. In fact, these minuscule marine organisms play an incredibly important role in the regulation of global climate. Not only are they responsible for removing half of the atmosphere’s carbon dioxide through their own processes of photosynthesis, but certain varieties of plankton are also known to be the principal generators of dimethyl sulfide, a gas that is vital in maintaining global temperatures. Dimethyl sulfide induces cloud formation over oceans, providing a layer of protection against the sun’s radiation. Without this beneficial cloud cover, the greenhouse effect would be intensified beyond what human activity has already been responsible for, with excessive radiation penetrating the atmosphere and being absorbed by greenhouse gases (carbon dioxide, methane, ozone, etc.), leading to an increase in global temperatures. Forget the “butterfly effect”—we’re talking about a “plankton effect” here.
As global warming continues to make its mark on our planet, a significant phenomenon that has come into play is ocean acidification, a process by which excess carbon dioxide is absorbed into seawater. One might assume that, seeing as plankton utilize carbon dioxide as fuel by which to photosynthesize and thus produce dimethyl sulfide, increasing the concentration of CO2 in the water would be beneficial. Unfortunately, as a recent study published by the European Project on Ocean Acidification (EPOCA) concluded, not all plankton are created equal.
In the spring of 2010, a team of European scientists began conducting an experiment off the coast of Norway to assess the impacts of increasing seawater CO2 levels on various plankton populations. By designing a series of semi-contained “mesocosms”—large buoy-like vessels consisting of a polyurethane bag allowing for the free movement of ocean water—these scientists could study how plankton blooms responded to ocean acidity in their natural environments.
As the levels of CO2 increased, the smallest varieties of plankton began to thrive, consuming more of the ocean’s available nutrients as fuel for photosynthesis. An increase in the populations of these smaller species, therefore, resulted in less available nutrition for larger plankton varieties. Unfortunately, it is these larger plankton who are the preliminary producers of dimethyl sulfide gas and the most effective at removing atmospheric carbon dioxide. Heightened seawater CO2 concentrations result in these larger varieties being outnumbered by their smaller relatives, creating a fundamental imbalance in the ocean’s food chain.
Whether we like it or not, global climate change is making its mark upon our planet. From ocean acidification to decreasing honeybee populations to altered concentrations of plankton to melting ice caps, any change in the structure of an ecosystem has the potential to adversely affect every level of life. If we choose to ignore seemingly unimportant changes happening in the world around us, they will lead to only greater consequences in the future. Yes, there truly is a “plankton effect,” and it’s going to take much more than a Krabby Patty to fix it.