A state Environmental Quality Department spokesman said Monday plant owner Temple-Inland was working closely with environmental officials to help get to the bottom of the fish kill, CNN reported.
Department spokesman Jeff Dauzat said the paper mill in Bogalusa had a problem with its wastewater equipment Aug. 9 and closed Saturday. WWL-TV, New Orleans, reported Saturday night Temple-Inland said it was possible the allowable discharge amount had been exceeded.
Community drinking water systems were not affected, state health officials said, but people were advised not to "come in contact with discolored water in the Pearl River and never collect dead or floating fish to eat."
Dauzat suggested "people stay off the water" until the cause of the fish kill is determined.
The Fish and Wildlife Service said the dead fish include paddlefish, American eels, catfish, bass, bluegill and shad.
Notable deaths of 2014 [PHOTOS]