Scientists have discovered that many tiny organisms in the ocean can both produce their own food and consume other organisms. This mixotrophic behavior affects nutrient cycling, primary production, and the carbon cycle in the ocean. By analyzing the hydrogen isotopic signature of lipids in these organisms, researchers found that it can reveal whether they are primarily eating or photosynthesizing. This method could help us better understand the impact of mixotrophy on the environment and the occurrence of Harmful Algal Blooms.