Photo By/Credit
John Heil/USFWS
Media Usage Rights/License
Public Domain
Image
“It was like looking for a needle in a haystack,” said Dr. Nicholas Som, a career mathematician and former school teacher in Colorado. “You can’t see them from the surface sitting in a raft. You have to be in the water on the bottom of the river looking for them.” Credit: John Heil/USFWS
Ecosystem
River/stream