Swan Lake has been experiencing a natural fish-kill phenomenon known as summer-kill, according to the Nebraska Game and Parks Commission. Dead fish include yellow perch, bluegill, largemouth bass, and channel catfish.

Swan Lake, located 11 miles southwest of Chambers in Holt County, has a high amount of algae in the water. Recent cloudy, calm weather has resulted in dying algae and, therefore, low dissolved oxygen levels, which are lethal to fish.

A sign of low oxygen is fish that appear stressed at the surface and are gasping for air. If oxygen levels drop low enough, fish death results. The conditions that lead to low oxygen levels can be reversed quickly; sunny, windy days can help alleviate summer-kill conditions.
Commission biologists have investigated the conditions and found varying dissolved oxygen levels within the lake. It is likely the summer-kill will not result in a total fish kill. The fish population will be monitored to determine if restocking is necessary.

Swan Lake was renovated to remove carp in 2007 and restocked with largemouth bass, bluegill, yellow perch, and channel catfish.