HARRISBURG, Pennsylvania- A naturally-occurring bacterium is being blamed for a massive fish kill in Pymatuning reservoir that prompted a do-not-eat advisory last month.

Officials tested fish samples and concluded the bacterium "Columnaris"  was triggered by several factors, including rapidly warming waters during spawning season.

The bacteria is not a health hazard and officials said fish caught in Pymatuning reservoir and Tamarack lake are safe to eat.