July 1966 



COMMERCIAL FISHERIES REVIEW 



27 



estimated 6,000 pounds were caught during a 

 3 -minute drag and off Chicago where 1,200 

 pounds were taken in 2 minutes. Soundings 

 also showed dense fish concentrations in 

 the harbors of Benton Harbor and Michi- 

 gan City. 



From Kenosha to Port Washington heavy 

 concentrations were also recorded in all 

 harbors. Drags in the ha rb o r s of Kenosha 

 and Port Washington yielded large catches 

 of alewives. In the open lake off those 

 ports the bulk of the ale wife had not yet 

 reached the beaches and heaviest concen- 

 trations were found at 15-19 fathoms. 

 Commercial trawlers fishing off Kenosha in 

 18-19 fathoms were catching 11,000 to 12,000 

 pounds per hour drag. A large catch esti- 

 mated at 5,000 pounds was made at 15 fath- 

 oms off Port Washington. Alewife apparent- 

 ly had not yet reached the harbors or beaches 

 from Sheboygan to Two Rivers where they 

 were found to be highly concentrated from 

 27-29 fathoms. The Kaho landed 1,600 pounds 

 in a 15 -minute drag at the same depth off 

 Two Rivers. Commercial trawlers in that 

 area were making comparable landings. 



Along the east shore from Ludington to 

 Holland, alewives were virtually absent in 

 the harbors and along the beaches. Weather 

 prohibited excursions into deep water to 

 search for alewife concentrations between 

 Little Sable Point and Saugatuck. The ab- 

 sence of alewife off Ludington has been noted 

 before during the same time of the year. 

 Scattered fish (possibly alewives) were sound- 

 ed at mid-lake in mid-water at about 50 fath- 

 oms. 



Phase II started and ended at Saugatuck, 

 Mich. Alewives were not found at any depth 

 off Saugatuck on April 19; however, by the 

 end of the cruise on April 28, heavy schools 

 were concentrated in front of the piers in 3j 

 to 4 fathoms where commercial trawlers 

 were making good catches. At all locations 

 where alewives were heavy, virtually no oth- 

 er fish were taken and only 2 yellow perch 

 were taken during the entire cruise. 



The Kaho , departed from the Saugatuck 

 vessel base May 3, 1966, on a 24-day explor- 

 atory fishing cruise in Lake Michigan, in- 

 cluding Green Bay. This cruise, the first of 

 two 24 -day surveys, covering the entire lake 

 was primarily concerned with completing 

 knowledge concerning the seasonal availabil- 

 ity of alewife and chub stocks to bottom trawl 



fishing gear at specific monitoring locations 

 in Lake Michigan and Green Bay. This infor- 

 mation, particularly that on alewife, will be 

 important to the newly developed Lake Michi- 

 gan industrial fisheries supplying pet food 

 manufacturers, and fish-meal reduction plants. 

 The commercial production of Lake Michigan 

 alewife increased from a mere 400 pounds in 

 1956 to nearly 15 million pounds in 1965. The 

 future potential size of this fishery appears 

 to be at least ten times this amount . 



Note: See Commercial Fisheries Review , April 1966 p. 26. 



1?* 



Great Lakes Fishery Investigations 



BIOLOGICAL RESEARCH AND 



SEA LAMPREY CONTROL, APRIL 1966 : 



Some of the highlights of Great Lakes bio- 

 logical research during April 1966 by the Bio- 

 logical Laboratory at Ann Arbor, Mich., op- 

 erated by the Bureau of Commercial Fisher- 

 ies, U. S. Department of Interior. 



Sea Lamprey Control: Electric barriers 

 in 13 of the 16 Lake Superior tributaries were 

 in operation by April 8. The Misery River 

 and Firesteel River barriers were activated 

 by April 13. Miners River weir is generally 

 placed in operation in early May. The total 

 catch of sea lampreys at the end of the month 

 was 125 compared to 23 a year earlier. Sea 

 lampreys were taken in 8 streams with the 

 Two Hearted River contributing 91 of the to- 

 tal catch. The 3 indexbarriers on tributaries 

 of northern Green Bay were operatingby April 

 4. A total of 25 sea lampreys were taken 

 by April 2 9. The Ocqueoc River barrier lo- 

 cated in northern Lake Huron near Hammond 

 Bay was placed in operation March 21, and 23 

 sea lampreys were captured by the end of the 

 month. 



Chemical treatment of lamprey-producing 

 streams was confined to southern Lake Michi- 

 gan and northern Lake Huron. Blue Creek, a 

 tributary stream in the o seph Ri^er sys- 



tem, was treated successiully with TF'M dur- 

 ing the last week in April. Pretreatment sur- 

 veys of northern Lake Huron streams sched- 

 uled for initial treatment were well underway 

 by the end of the month and the treatment crew 

 had preliminary preparations in progress. A 

 comprehensive survey of Lake Michigan 

 streams scheduled for treatment along the 

 west shore failed to disclose sea lamprey 

 ammocetes in the State of Wisconsin. A num- 



