CHEYENNE — Summer temperatures throughout the Cowboy State have resulted in some streams and rivers running at warmer temperatures, leading the Wyoming Game and Fish Department to ask anglers to adjust their fishing practices during the hottest part of the summer.

The WGFD says warmer water temperatures can impact fish survival, especially in the state’s trout populations.

“It’s that time of year when water temperatures are highest. Warmer surface temperatures have the potential to be lethal to trout,” Alan Osterland, WGFD fish division chief said. “Warm water also holds less oxygen which can stress not only trout, but also all fish.” 

Trout die after prolonged exposure to water temperatures greater than 75 degrees Fahrenheit, and brief exposure to temperatures over 80 degrees are lethal. Fish stress quicker in low-oxygen, warm water, which greatly hampers a fish’s ability to recover from the rigors of being caught. However, as water temperatures approach 70 degrees, the chance for any fish species to survive being caught and released is reduced.  

“As water temperatures increase, anglers should monitor water temps while fishing. When water temperatures hit 70 degrees, we recommend anglers stop catching and releasing fish,” Osterland said. “Practice self-restraint to help fish survive.”

The WGFD asks all anglers practicing catch-and-release to consider the following:

• Fish early in the morning while the water temperature is cooler.
• Carry a pocket thermometer to monitor the water temperature.
• If the water temperature is at or above 65 degrees, consider keeping what you catch within the regulations. If the temperature is 70 degrees or higher, do not attempt to catch and release fish. 

As water temperature increases, using the proper techniques to catch and release a fish becomes increasingly important to help ensure the fish has a chance to survive:

• Play and land fish as rapidly as possible to reduce exhaustion stress.  
• Keep the fish in the water as much as possible.
• Do not squeeze the fish or place fingers in the gills.
• Remove the hook gently. If hooked deeply, cut the leader.
• Flies and lures are recommended whenever many fish are being caught and released.
• Barbless hooks allow easier hook removal.
• If a fish is exhausted and cannot hold itself upright, and if regulations allow, consider having it for supper because the fish has a poor chance of surviving.

“These are not new regulations, just recommendations to assist with the conservation of the fishery resource,” Osterland said. “If water temperatures are too high, consider escaping the heat with a trip to another top-notch, high-country fishery where it’s cooler.”