TWIN FALLS - Idaho officials say the discoloration of the Snake River is likely caused by the bloom of some sort of dinoflagellate.
The Idaho Department of Environmental Quality says dinoflagellates are microscopic plankton in the general category of algae.
It says algae are a natural component of the aquatic food chain and are typically not harmful to people.
However, too much algae can be potentially harmful to the environment.
The Times-News reports that the algae bloom can be attributed to a number of factors that act in combination with each other, including higher water temperatures, low water flow and excess nutrients.
There are no short-term solutions to correct an algal bloom other than waiting for the weather to change.
The Snake River begins in northwest Wyoming.