UPDATE: Chattanooga Fire Department Special Operations personnel determined the substance found Monday in the Tennessee River was a form of algae and not an environmental hazard. 

PREVIOUS STORY: The Chattanooga Fire Department was called to Ross's Landing Monday afternoon for a substance in the Tennessee River.

Crews have deployed booms in the water near the Tennessee Aquarium to prevent the substance from going further downriver.

Crews responded to investigate the substance & gathered samples to test it.