Harmful aspects of Algae
Some algae species like Microcystis, Lyngbya are develop water blooms in water areas. They secrete toxic materials into water. That they polluted the water.
The algae, Cephaleuros virescence causes for red rust tea in tea plant.
Some algae species are caused for some skin diseases.
Dianophlagellate is caused for the death of fishes in water.