The completion oi'" the Trent Waterway connecting Lake Ontario 

 and Georgian Bay (Lake Htiron) in 1918 opened another possible, but 

 somewhat improbable, means of introduction into the upper lakes. 

 This system consists of approximately 235 miles of circuitous 

 waterway extending from Trenton, Ontario, on Lake Ontario to Port 

 Severn on Georgian Bay of Lake Huron. It embraces li.6 boat locks, 

 32 l/k miles of constructed canal, and numeroiis power and water 

 level maintenance dams creating heads as great as ^8 feet. Boat 

 traffic in the system is not heavy. The sea lamprey might have 

 distributed itself into Lake Huron by this route, but the weight 

 of evidence indicates that they gained entrance to the upper lakes 

 via the Welland Canal. 



In the two and one half decades follomng the captiore in 1921 

 of the first adult specimen in Lake Erie, the sea lamprey has 

 dispersed rapidly throughout the upper lal<:es establishing itself 

 in Lakes Erie, Huron, and Michigan in that order. Recent reports 

 indicate that it had become established in Lalce Superior at least 

 by 19li5. Although its spread and multiplication has not approached 

 the spectacular quality of another exotic introduction, the smelt 

 ( Osmerus mordax), it is nonetheless firmly established and present 

 in large numbers. 



The history of the spread of the sea lamprey in the Great 

 Lakes is written in the chronologT' of all available records, 

 published and unpublished. A summary is presented hereivith, by 

 drainages, which documents its spread. The period covered is 1921 

 through I9U8. This is the interval during which the establishment 

 of the sea lamprey was recognized throughout the Great Lakes. In 

 the folloiving suimnary, notations concerning the nature of the 

 record and the sou3K;e are included wherever possible. 



1921 



Lake Erie and tributaries . — One specimen, 21 inches long, talcen off 

 shore from Merlin, Ontario, in central lake Erie on November 8, 

 1921 (Dymond, 1922). 



1927 



Lake Erie and tributaries . — One specimen caught near 'ffest Sister 

 Island, Ohio, on November II4., 1927 (Osbiim, Wickliff and 

 Trautman, 1930)- One specimen caught near Sandusky, Ohio; 

 identified by Dr, John Van Oosten (Hubbs and Brown, 1929). 



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