Heat and Fish Handling

When both water and air temperatures are uncomfortably hot, consider relieving trout of angling pressure by finding a target species that is better equipped to handle high temps.

The summer is rolling into the Bozeman area ahead of schedule this year and the rivers are experiencing an abnormally low amount of runoff compared to seasonal averages. The waters surrounding Bozeman receive a lot of pressure from anglers, especially in the summertime. For fly fishers, the summer is the favorite time of year to enjoy our sport, when the fish are the most active and the weather allows us to enjoy the river in shorts and Ts. But due to the low amount of water in reservoirs and rivers, the water temps will rise faster than usual and the trout will be at higher risk of dying when caught.

Happy Trout

Our target species, trout, are cold-water fish that needs sub-70-degree water temps to flourish. Preferably, trout like to live in water that ranges from 54-64 degrees, this is where they are happiest, although for shorter periods of time they can withstand temps up to 80 degrees, as long as they remain unstressed.

Different species of trout can withstand varying highs in water temperature. Some species, such as cutthroat and brook trout, need relatively colder water temperatures compared to brown and rainbow trout. Therefore these cold-water species are more susceptible to fatigue and over-exertion when being caught during high water temperatures. As anglers, it is important we preserve the resources that important to us and take care of our prized trout populations.

Keep 'Em Wet

Anglers inherently put stress on fish, due to the nature of the sport, by catching and releasing them back into the water. When water temps rise above 70 degrees the fish mortality rate increases due to the lack of oxygen that is available in warmer water. The phrase “keep ‘em wet” is much more important once water temps spike in rivers in Southwestern Montana. There is less oxygen available in warm water and fish are unable to feed and grow at the same rate. When fishing, it is good practice to land the fish as quickly as possible and keep them in the water as they are being released.

During these periods of heat, it is important to treat the fish with respect by reviving the fish as quickly as possible once it is landed and saving the grip and grin photo ops for another day, once the water returns to a more stable temperature. Another good habit to preserve fish is to use heavier tackle in order to limit the amount of time the fish is on the line. The less time the fish is being fought on the line the easier it is for the fish to recover from the ordeal. After quickly bringing in a fish, land it with a net and avoiding beaching our scaly friends. When an angler uses a not he or she can often unhook and release a trout without ever touching or taking the fish out of the water. By enacting these techniques we can preserve our trout populations and effectively practice catch and release that does not result in the fish dying soon after they are caught.

Other Fly Fishing Options

In some bodies of water, the temps will rise above 70 degrees, in this scenario, it is best to let the trout rest and target species that can withstand warmer temps. Bass, bluegill, carp, and pike are viable target species on the fly and do not have the same need for cold water temperatures. Remember to be conscious of the fish and their needs during the summer, check the temperatures, and head to streams that remain cool as the summer heats up. Stop by our Bozeman fly shop for the best gear and flies available for targeting warm-water species.