More than 54,000 dead fish have been found in Blounts Creek in eastern North Carolina.
The North Carolina Division of Water Quality says the fish were found Wednesday morning in the upper part of the creek in Beaufort County. The creek feeds into the Pamlico River.
Spokeswoman Susan Massengale says the dead fish included menhaden, spot, sunfish, bream, gizzard and shad.
Massengale says low dissolved oxygen levels were measured at the surface and three feet below the surface throughout the area where the dead fish were found.
She says officials are trying to determine what caused the oxygen levels to drop. Water samples have been sent to a lab in Raleigh for analysis.