Largemouth bass, introduced through unauthorized plants are well established in the Thompson 

 Lake chain. In recent years, the Thompson lakes have been popular for bass fishing tournaments. 

 The Northwest Montana Bassmaster Club has placed artificial habitat structures in Middle 

 Thompson Lake to enhance bass populations. Bass are able to avoid gill nets (due to their body 

 form and agility) so FWP uses catch per effort ftx)m bass tournament contestants to identify trends 

 in the bass population (Table 7). 



Table 7. Results from bass tournaments held on Middle Thompson Lake, Montana 1989 - 1993. 



In 1990, starch gel electrophoresis done on bass populations in northwest Montana indicated bass 

 populations v/ere not vay diverse genetically (they appeared to be nearly clones of one another). 

 Low goietic divQ^ty is a problem because it can lead to complications such as low fecundity (egg 

 production) and low survival. In 1991, FWP attempted to increase genetic diversity by hatchery 

 supplementation. FWP stocked 32,600 fingerling bass in Middle Thompson Lake in hopes that 

 whoi they mature, they will randomly breed with the wild population and introduce new genetics 

 into the population. 



Currently most angling is directed toward kokanee and largemouth bass. Kokanee provide both 

 a summer and winter fishery. Trout catch rates are low but steady and some anglers specialize 

 in pursuing trophy trout (greater than 10 pounds). Catch rates on yellow perch are high but only 

 a very small percentage of the perch are considered to be of keeping size (greater than eight 

 inches). Spearing was banned on the lake in the 1970s to discourage poaching. Trout anglers are 

 restricted to 5 trout daily, only one trout longer than 22 inches. This regulation was established 

 in an attempt to protect tfie trophy trout fishery and to spread harvest among more anglers. Bass 

 anglers are restricted to only 1 bass daily, minimum length of 22 inches from May 15 to June 30, 

 to protect spawning bass and to spread harvest throughout the year. 



Managpmp nt Concerns : 



1. As with all TCL lakes, yellow perch, pumpkinseeds, and northern pike introductions can 

 make successful stocking of rainbow trout difficult. 



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