The blue green algae is found in almost every conceivable habitat, from oceans to fresh water to bare rock to soil. Most of it is found in fresh water, while others are marine, occur in damp soil, or even temporarily moistened rocks in deserts. A few are endosymbionts in lichens, plants, various protists, or sponges and provide energy to the host. Some blue green algae live in the fur of sloths, providing a form of camouflage while they are safe. And it mostly neutralize the alkalinity in plants.
