ILLUSTRATIONS 



FIGURE PAGE 



lo Map of upper Great Lakes showing established sea lamprey 



2. Map of northern Lake Huron and Straits of Mackinaw 



showing location of weirs and traps in Control Zone H-i . . 3 



3. Portable-type weir and trap in Milligan Creek, Presque 



J. s x c vO un iy * in cni^ a. n 0«o*«o***eo«e*«ss«o««o*««*»«*»**««0» /4 



lu Small portable-type weir and trap in Cedar Creek, 



Presque Isle County, Michigan h 



5. Large portable-type weir and trap in Pendill's Creek 

 Chippewa County, Michigan 5 



6. No. of sea lampreys taken each day during 1950 season in 

 five northern Lake Huron tributaries of different size 

 and character, and mean stream water temperatures for 



period „ 26 



7. No. of ssa lampreys taken each day during the 1950 

 season in five streams in different geographic latitudes 



with mean stream water temperatures for period 28 



8. Power dam in Cheboygan River at Cheboygan, Michigan 31 



9. Peterson-type tag applied to migrant sea lamprey 32 



10. Small-scale chart of upper Great Lakes showing general 

 dispersion of marked lampreys from blockaded spawning 



11. Large-scale chart of Control Zone H-l (northern Lake 

 Huron) showing movements of marked lampreys from 



blockaded Cheboygan River spawni ng run 33 



12. Permanent- type sea lamprey xjeir and trap in Ocqueoc River, 

 Presque Isle County, Michigan 39 



13. Dam and inclined-screen sea lamprey trap in Carp Lake 



River, Emmet County, Michigan 39 



