streams in which sea lamprey nests were observed or reported (see also 

 table 2'3yt 



1950 siirvey areas lli (Additional records available from rechecks 

 made in 1951 will be presented in a later report), 



1951 survej'- area: 1 



It is nrobable that nests were present in other streams but were 

 not observed because: 



1. The general rarity of nests in the Lake Superior region 



would make it entirely possible to miss an occasional single 

 nesto 



2o The brown color of many streams may have obscured some nests. 



3. Nests may have been destroyed in streams examined long after 

 the spawning seasono 



Streams in which sea-lamprey larvae were obtained (see also table 23) ; 



19$0 survey areas 1 (Almost all streams were examined for larvae| 

 lamprey larvae of several species were obtained from 23 

 streams) . 



1951 survey area; none (No streams in this area were checked for 

 larvae) . 



Streams upon which some type of control may eventually be necessary; 



19^0 survey area; 112 



1951 survey area: I36 



Tributary streams in this group can be controlled by devices 

 placed on main streams. The need for control on many of these streams 

 can be determined only by future examination „ 



Stream mileages; Over 1,300 miles of stream were surveyed in 19^0; 

 the combined lengths of all streams in the area amount to considerably 

 more than that. The lengths of all streams in the 195l area aggregate 

 over 1,500 miles, of which several hundred miles were surveyed. 



