Explanation:

Blue-green algae are actually types of bacteria known as Cyanobacteria. They normally look green and sometimes may turn bluish when scums are dying. Cyanobacteria, also known as Cyanophyta, are a phylum of bacteria and plastids that obtain their energy through photosynthesis. They are the only photosynthetic prokaryotes able to produce oxygen. The name cyanobacteria comes from the color of the bacteria. People may become ill after swimming or water skiing in lakes with toxic blue-green algae. Rarely, humans may experience stomach pains, vomiting, diarrhea, and skin rashes (dermatitis/swimmers itch). Nerve and liver damage have been observed following long-term exposure such as drinking water with toxic blooms.