A number of dead fish have turned up along the Concho River near Mullins Crossing Road in Miles, TX.
Texas Parks and Wildlife tells Fox News First it could be caused by golden alga; a single-celled organism which when "blooms" may be harmful to fish, mussels and clams.
"I live on this river so I'm here every day," Tommy Evridge, a fisherman and area resident, said.
Evrdige says he's never seen this degree of fish kills.
"You can smell them," he said. "It's not good, I'm sure it's not good."
According to the TPWD's website the alga is not harmful to humans, other mammals, or birds. However they advise against consuming or touching the fish.
If you see a number of dead fish in your local river or lake or suspect golden alga you may contact the TPWD's 24-hour communications center at 512-389-4848 or visit their website.