Here’s the release from Colorado Parks and Wildlife:
Due to low water levels and oxygen deprivation, North Sterling State Park has suffered a nearly complete fish kill, as of Tuesday, Sept.18.
North Sterling State Park employees began seeing a few dead fish on top of the water on Saturday, Sept. 15. By Tuesday, Sept. 18 dead fish littered the entire south and east shorelines of the reservoir. Due to the species and the number of fish found, this appears to be a complete fish kill, meaning all of the fish that used to inhabit the reservoir are likely dead.
“Based on the fish that I and park staff observed at the reservoir, the fish kill is due to low oxygen levels in the reservoir,” said Mandi Brandt, aquatic biologist. “Colorado Parks and Wildlife will begin work to rebuild the fishery as soon as better conditions are available, hopefully next spring.”
As the primary function of North Sterling Reservoir is to store irrigation water, the water level has been severely drawn down during 2012, leaving a relatively small pool of water for fish to inhabit. Recent winds across the shallow pool resulted in a turnover, where water near the surface of the pool was forced to the bottom of the pool and water near the bottom of the pool is forced to the top, effectively mixing the whole pool. Water at the bottom of the pool is low in oxygen due to decaying organic matter. When this water is mixed throughout the pool the oxygen level throughout the entire pool is driven down, leaving little oxygen for fish to survive.
CPW employees found dead wiper, walleye, saugeye, channel catfish, crappie, bluegill, green sunfish, freshwater drum, common carp, and gizzard shad.
Due to severely low water levels in Jumbo Reservoir, Prewitt Reservoir, and Jackson Reservoir, anglers who would like to fish in the upper northeast corner of the state are encouraged to fish at Jumbo Annex Reservoir or Stalker Lake.