conclusively, by capture in grids. 



Conclusions and Recommendations 



The Arctic grayling population in the Big Hole River system has 

 been detrimentally impacted by an unknown combination of factors in 

 the recent past. Changes in water use, land use, and the introduction 

 of non-native species are among the factors which could have 

 contributed to an overall decline in the grayling population. The 

 isolation of factors that may be contributing to the decline of this 

 population is difficult in a system as large as the Big Hole River 

 drainage. Studies such as this, which focus on the present 

 distribution of, and habitat utilization by, a particularly sensitive 

 segment of the population (the young-of-the-year) are important and 

 useful in that they add to the base of knowledge available for future 

 management decisions and serve as pieces in the puzzling question of 

 why this population is so rapidly declining. 



Work by Skaar (1989), Shepard and Oswald (1989), Liknes (1981), 

 and Kaya (1989) has brought forth information on the distribution, 

 habitat utilization, and behavior of these fish. Much more work is 

 needed however before the problem of the declining grayling can be 

 remedied. The Montana Department of Fish, Wildlife and Parks has 

 collected fertilized eggs from one spawning season (1988) and planted 

 the fry in a mountain lake for future brood stock of Big Hole River 

 Arctic grayling in the event that they are needed to restock or 

 supplement the population in the Big Hole River. This type of 

 management may be largely ineffective, however, until the problems 

 within the system are identified and steps are taken to lessen their 

 negative effects. 



Laboratory studies on interspecific competition between grayling, 

 brook trout, and brown trout will help to clarify the role of 

 introductions of brook trout and brown trout in the decline of the 

 grayling. Thermal studies concerning the tolerances of all life 

 stages of grayling as well as continued field studies, particularly 

 those focusing on the winter habitat use of the grayling and the other 

 salmonids and land and water use in the Big Hole River Valley, are 



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