FISHERIES MANAGEMENT 



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Many sensitive instruments are used in the science of fisheries nnanagement. The tape shown in actual size above is from an echo sounder. The 

 echo sounder shows water depths, lake bottom configuration, and general configuration of other objects in the water. The heavy line at top 

 represents Flathead Lake surface. The irregular heavy line at the bottom represents the lake bonom. Small dots in between are fish, and the 

 dot cluster immediately above inset of Flathead work boat shows a school of fish. 



The fishery management program was 

 characterized during the biennium by efforts to 

 preserve, protect and restore fish habitat, resulting 

 in improving the quaUty and quantity of Montana's 

 overall fishery. AppUcation of research, intensified 

 co-ordination with construction agencies under the 

 Stream Preservation Act and initiating closer 

 co-ordination with agencies and individuals not 

 covered by the Act were among techniques used to 

 improve Montana's position as the number one 

 trout fishing state in the nation. 



Bluewater & Rock Creek Study 



Stream fishing in Montana is predominantly the 

 result of production of wild trout, which require 

 quality water for continued production. Studies of 

 Bluewater Creek near Fromberg and Rock Creek 

 near Red Lodge demonstrate the detrimental 

 effects of silt and sedimentation on trout survival. 

 It was found that a great deal of these streams' silt 

 burden was caused from man-made reasons, and 

 when the erosion-siltation sources were rectified to 

 alleviate siltation there was an accompanying and 

 proportional increase in wild trout. The studies are 

 continuing to analyze sources and control of soil 

 erosion and stream bank breakdown. The 

 information obtained will greatly benefit fish 

 habitat and the streams carrying capacity for fish, 

 and be of value to property owners in terms of 

 channel stabihty and soil retention. 



River Electrofishing Project 



Big rivers, like the Madison, Missouri, Jefferson, 

 Yellowstone and Big Hole are very popular with 

 Montana anglers and are a major tourist attraction 

 in Montana. Because of their size, it has been 

 previously impossible to sample and research them 

 as smaller streams can be handled. Research 

 technique breakthroughs now make possible the 

 gathering of adequate and accurate information to 

 manage these large rivers in a manner to enhance 

 and sustain this already tremendous fishery 

 resource. During the past two years, surveys have 

 been made on the East Gallatin, Madison, 

 Beaverhead, Ruby and Shields Rivers, and O'Dell, 

 Rocky and Prickly Pear Creeks, and started on the 

 West Gallatin and Yellowstone Rivers. Information 

 to date reveals large rivers have a tremendous 

 annual turnover of game fish, just as small creeks 

 do, httle of which is due to fishing pressure. The 

 Madison, heavily fished by Montana standards, has 

 been discovered to lose only 1 2% of its annual fish 

 mortaUty to anglers. From this type of information 

 it can be readily calculated just how much fishing a 

 large river can provide and what sort of regulations 

 are needed, if any, to insure the potential is not 

 exceeded. 



Flathead Lake Study 



Flathead Lake, the largest fresh water lake west 

 of the Mississippi, is among the very top fishing 

 attractions in Montana. Fishery managers have 



