Thirteen thousand fish went belly up in Blounts Bay this week, and officials say a sudden drop in oxygen levels is to blame. Blounts Bay is located on the Southside of the Pamlico River. A citizen spotted the dead fish Wednesday morning. About 11,000 of them were Spot, another thousand Croaker, and the rest a mix of Menhaden and Blue Crab. The oxygen drop was picked up by a U.S. Geological Survey monitoring station, between midnight Tuesday to 3 a.m. Wednesday. The level has since rebounded.