July 1966 



COMMERCIAL FISHERIES REVIEW 



29 



"Planned re-treatment of the Great Lakes 

 tributaries does not mean that earlier work 

 was a failure," said the scientist in charge of 

 the Bureau's sea lamprey control program. 

 "Actually, we've scored heavily on the sea 

 lamprey in our first round of chemical re- 

 leases and now we're going back to some of 

 these waters with hopes of knocking out lam- 

 prey populations which have become re-es- 

 tablished," he explained. 



Latest studies indicate that lamprey num- 

 bers in previously treated Lake Superior 

 streams have been reduced by 80 percent 

 over the last 4 years. 



The most encouragement of the lamprey 

 control program comes from evidence of 

 natural reproduction among lake trout in Lake 

 Superior. Noteworthy, too, are signs of high 

 survival among hatchery -reared lake trout 

 planted in Lake Superior. 



In Lake Michigan, where treatment work 

 started later than in Lake Superior's streams, 

 it appears that fishery workers also have 

 been successful in reducing the sea lamprey. 

 The Bureau has high hopes that its follow-up 

 treatments in Lake Michigan streams will 

 have the same results now showing up in Lake 

 Superior. 



Note; See Commercial Fisheries Review , June 1965 p. 21. 



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GREAT LAKES SEA LAMPREY 



TAGGING PROGRAM: 



In a notice to members of the Great Lakes 

 commercial fishing industry, the regional of- 

 fice of the U. S. Bureau of Commercial Fish- 

 eries at Ann Arbor, requested all fishermen 

 to be on the alert for tagged sea lampreys. 

 The recovery of tags from sea lampreys will 

 provide valuable information to aid in further 

 reducing the numbers of that parasite in the 

 Great Lakes. Anyone catching a sea lamprey 

 with a tag attached is requested to send the 

 tag, information as to date, size of the lam- 

 prey, exact location, and method of capture 

 to the Bureau of Commercial Fisheries, U. S. 

 Department of the Interior, P. O. Box 640, 

 Ann Arbor, Mich., or to the Fisheries Re- 

 search Board of Canada, Biological Station, 

 Ships Canal Post Office, Sault Ste. Marie, 

 Ontario, Canada. 



The sea lampreys are being marked with 2 

 conspicuous tags. The first type consists of 

 2 colored disks fastened by a nickel pin to the 



back of the animal. The second tag is a plas- 

 tic tube which is passed through the back of 

 the lamprey and joined to form a circle. 

 Markings on the tag provide biologists with 

 the date and location where the sea lamprey 

 was tagged. Persons returning tags will re- 

 ceive an acknowledgment with information on 

 movement and growth of the sea lamprey from 

 which the tag wa."; taken. 



Biological data obtained from the tag re- 

 turns will provide valuable information on the 

 life history and movements of sea lampreys 

 in the Great Lakes. This information is need- 

 ed to evaluate the success of the chemical 

 program to control the sea lamprey. 



Gulf Fisheries Explorations 

 and Gear Development 



SHRIMP GEAR STUDIES CONTINUED: 



M/V "George M. Bowers" Cruise 64- 

 Phases U, IV, VI, and VII (February 21 -May 

 6, 1966): A 42 -day exploratory cruise off the 

 southwestern coast of Florida, Tampa to Key 

 West, was completed May 6, 1966, by the U.S. 

 Department Interior, Bureau of Commercial 

 Fisheries ' exploratory fishing vessel George M. 

 Bowers. 



The Bureau's exploratory fishing vessel George M. Bowers . 



The cruise objectives were: (1) initial 

 field testing of a prototype electroshrimp 



