Cyanobacteria, also known as blue-green algae, are a type of microorganism that can be found in many aquatic environments. They have the unique ability to produce their own food through photosynthesis, which means they need light to survive and thrive. Without sufficient exposure to light, cyanobacteria will eventually die off or become less productive. In addition to needing light for photosynthesis and energy production, some species of cyanobacteria require additional nutrients from external sources such as nitrogen and phosphorus for optimal growth. Therefore it is important for their environment to provide both an adequate amount of sunlight and the proper nutrient balance in order for them to flourish.