Low oxygen levels affecting Taneycomo trout

BRANSON, Mo. – Fall can be a great time to go fishing, but anglers who pursue trout at Lake Taneycomo need to be mindful that current water-quality conditions make this a stressful time of year for the reservoir’s premier sportfish.

The main cause of stress to the trout is low levels of dissolved oxygen (DO) in Taneycomo’s water. Cooler temperatures will remedy this situation. In the meantime, anglers who fish Taneycomo and plan to release trout they catch can reduce stress to the fish by minimizing the time they take to reel in and release fish. Land trout as quickly as possible. Extended fights stress fish at any time of year, but can be lethal during times of low DO. Also, minimize the time spent netting and unhooking fish. Finally, when the fish is unhooked, gently hold it under water until it can swim off on its own.

Anglers might also notice trout in Lake Taneycomo are more lethargic and less likely to take a lure at this time of year. Anglers shouldn’t worry; fishing will improve as DO levels improve.

Cold water released into Taneycomo from the depths of Table Rock allows trout to thrive in the upper end of Taneycomo during most of the year. However, beginning in late summer and continuing through fall in most years, cold water coming into Taneycomo from Table Rock routinely diminishes DO levels due in an annual process known as stratification that occurs over summer in Table Rock. Warm water that’s less dense with adequate DO near the surface does not mix with denser, cooler water deeper in the lake. This depletes DO in the deep layer of the lake.

This low-DO water gets released into Taneycomo. Some autumn trout mortality occurs at Taneycomo each year as a result of this process, but this mortality can be reduced by anglers practicing good catch-and-release methods.

As temperatures become colder; the upper oxygenated layer of water in Table Rock cools, become denser, and sinks. Once the surface water temperature reaches the same temperature as on the bottom, Table Rock Lake will turn over, resulting in a more even distribution of dissolved oxygen throughout all layers of the lake. The release of this water into Taneycomo will help solve that reservoir’s low DO problems and help fishing return to normal.

In Missouri, from both a participant and economic perspective, trout fishing is significant. Trout fishing activity in the state generates retail sales of $104 million and has an annual economic impact of $187 million. Trout fishing also supports more than 2,300 jobs.

More information about trout and about other fishing opportunities in Missouri can be found at www.mdc.mo.gov/fishing.