There’s something fishy going on at Tantra Lake.

Hundreds of fish turned up dead in the south Boulder lake over the weekend, prompting concerns from residents in the area.

Melissa Miller said she first noticed the dead fish Sunday morning while walking around the lake, located at 1000 W. Moorhead Circle.

“It just smelled like fish,” Miller said. “I thought maybe a fisherman had left a fish on the grass, but then I saw all of them.”

The dead fish, ranging from smaller ones measuring only a few inches to larger carp several feet long, could still be seen this morning floating by the hundreds in the lake, and the smell of dead fish lingered in the air.