An algal bloom is slowly moving down the Ohio River and a Harmful Algal Bloom Recreational Advisory has been issued. The Indiana advisory was issued by the Indiana Department of Environmental Management, in coordination with neighboring states, on 9-18-15. The bloom consists of blue-green algae, also known as cyanobacteria. It has the appearance of blue-green paint or scum in the water and can be toxic. Due to the toxins, avoid contact with the water (this includes pets)!
The Louisville WFPL website has an excellent article on this issue, with a map of the affected sections of the Ohio River and brief description about why the algal bloom is occurring.
This advisory is a recreational contact advisory only, with finished drinking water reported as being safe. The Louisville Water Company is taking extra measures to protect the drinking water supply that comes from the Ohio River.
This event is being reported as the worst toxic bloom in the history of the Ohio River.