New Bern, N.C. — The total number of fish found dead along or near the Neuse River doubled after state officials counted 6.5 million dead fish on Tuesday and Wednesday.

State Division of Water Quality spokeswoman Susan Massengale said that approximately 12.3 million dead juvenile Atlantic menhaden fish have been found since the last week of August.

This week, 650,000 fish were found in Northwest Creek and Fairfield Harbor, which are somewhat separated from the Neuse, Massengale said. The rest were found in the Neuse, between New Bern and Carolina Pines.

Large, dense schools of live menhaden were seen the length of the kill. Massengale said that staff reported that fish near New Bern appeared lethargic, while schools further downstream appeared to be more active and healthier.

So far, Massengale said, testing indicates the fish died when low-oxygen saltwater along the river bottom mixed with the upper layers of fresh water. Environmental officials are also testing samples from an algae bloom.

None of the dead fish have had lesions.

Earlier, dead fish were found along 10 miles of the Neuse's southern shore between Black Beacon Point and Carolina Pines in Craven County.