How does algae help people?

Humans use algae as food, to produce beneficial compounds as biofilters, to remove nutrients and other pollutants from wastewater, to analyze water quality as an indicator of environmental change, in space technology and as laboratory research systems. Algae are commercially grown for pharmaceuticals, nutraceuticals, cosmetics, and aquaculture. Algae can be used to make biodiesel, bioethanol and biobutanol, and by some estimates it can produce significantly higher amounts of vegetable oil than land crops grown for the same purpose.