(Zone 1) 



In Zone 1 (see Figure 28), the general tyoe of nest built 

 was one of various size gravels in riffles, bars, and flat beds, 

 or on scattered patches of gravel (Figure 33). Ultimately, all 

 available graveled locations of every description in this zone 

 were completedly used, although certain types of locations were 

 more suitable for nest construction than were others. Jn a 0. it-mile 

 area between Stations IL and IM, the specific sites of 1,820 nests 

 present were determined. Of this total, 1,0U3 nests were built on 

 ten long, gravel riffles totaling 1,070 feet of linear stream 

 distance (range in length of individual riffles; 35-500 feet); 

 h3h nests were constructed on isolated, large, transverse gravel 

 bars and short riffle areas; 120 nests were made on scattered, 

 small, transverse bars; 60 nests were built at the upstream or 

 downstream margins of pools or in the deeper areas intermediate 

 between isolated bars or riffle areas; 63 nests were located on 

 linear (parallel to current) graveled areas and 60, on scattered 

 patches or pockets of gravel. These last two types of sites were 

 in generally sandy-bottomed areas of the river. Of the remainder, 

 3li nests were constructed on flat and ridged gravel beds on the 

 outside margin of deep pools at bends in the river, and 6 in a 

 like location on the inside of a river bend. 



Figure 33. — Sea lamprey nest; tj^e characteristic of graveled or 

 gravel bar areas. (Ocqueoc River, Zone 1, Station IM, 

 June 10, 19U6c) 



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