N. Kröger, TU Dresden

Tiny drifting algae called diatoms generate about 20 percent of the oxygen produced on Earth each year—more than all of the world’s rainforests. A new study from the College of the Environment’s School of Oceanography and Seattle’s Institute for Systems Biology looked at how common species of diatoms will adjust to sudden and long-term increases in carbon dioxide. The scientists found that when CO2 spikes, as might happen during a sudden change in ocean currents, the diatoms produce a signaling molecule that reduces the energy-intensive process required to concentrate the carbon dioxide. When the CO2 remains high for longer periods of time, however, the diatoms make a more radical metabolic shift. They decrease photosynthesis and respiration to balance the cell’s energy budget. In other words, the diatoms use less energy to grow at the same rate. Understanding the genetic machinery for how diatoms respond to rising carbon dioxide levels could help predict the future of the world’s oceans and determine what role diatoms play in the Earth’s future atmosphere.