(Casper, Wyo.) – Because Wyoming is grappling with unseasonably high temperatures, trout are grappling with reduced food and oxygen and in many instances their very survival.
The conditions have the Wyoming Game and Fish Department’s fish management staff very concerned about the impacts on both fish and anglers.
As the water levels drop, the temperature rises. Cool and warm waters species such as walleye or bass can generally tolerate the harsher conditions — but warm water is a real threat to trout and other coldwater species.
Casper Region Fisheries Supervisor Al Conder reports trout experience significant mortality at prolonged exposure to water temperatures greater that 75 degrees Fahrenheit and brief exposure to temperatures over 80 degrees can be lethal. Flow in the North Platte River below Gray Reef was reduced to 500 cubic feet per second the end of August, causing the water temperature to rise. “With the unseasonable high temperatures, water temperatures at Glenrock are approaching 80 degrees,” Conder said.
Fish stress quicker in warmer water because the water holds less oxygen, which greatly hampers a fish’s ability to recover from the rigors of being caught. Catching and releasing a trout in 40-degree water or a walleye in 50-degree water is not a problem if done correctly.
However, as water temperature approaches 70 degrees the chance for any fish to survive being caught and released is greatly reduced.
Water temperature is particularly important for anglers practicing catch and release or where our regulations require fish to be released. Game and Fish asks all anglers practicing catch and release to consider the following:
- Fish early in the morning while water temperature is cooler.
- Carry a pocket thermometer and monitor the water temperature.
- If the water temperature is at or above 65 degrees, consider keeping what you catch within the regulations; if 70 degrees or higher, do not attempt to catch and release trout.
- As water temperature increases, using the proper techniques to catch and release a fish becomes increasingly more 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. If water temperatures are high perhaps try fishing for a different species or escape the heat with a trip to the high country.