Algae are used in producing biofuels, food supplements (spirulina), fertilizers, cosmetics, and medicines. They are also used as a thickening agent in products like ice cream (e.g., agar, carrageenan).

Food: Seaweeds (nori, kelp) used in sushi; spirulina as protein powder.
Medicine: Agar and carrageenan used in capsules and labs.
Fertilizers: Enrich soil with nutrients.
Cosmetics: Used in creams, shampoos, face masks.
Biofuels: Algae oil used for making renewable energy.