July 1966 



COMMERCIAL FISHERIES REVIEW 



25 



As part of the planting program in the Big 

 Huron River, also liberated were 50,000 year- 

 old rainbow trout under an accelerated pro- 

 gram to boost steelhead runs in Great Lakes 

 streams. ( News Bulletin, Michigan Depart- 

 ment of Conservation, Lansing, M ay 19, 1966.) 



Note: See Commercial Fisheries Review , February 1966 p. 18. 

 sic ii'fi sl< 5;< >!« 



FISH BLOCK PRODUCTION OF 

 UNDERUTILIZED FRESH-WATER 



SPECIES STUDIED: 



Fish blocks for the production of fish 

 sticks and portions generally are in short 

 supply and are principally from foreign 

 sources. Blocks likely will remain scarce 

 until underutilized species now available to 

 the domestic fishery can be used. The po- 

 tential market for fish blocks made from a- 

 bundant underutilized fresh-water fish ap- 

 pears good. Why not then, simply start catch- 

 ing those fish and making them into fish 

 blocks? This question has to be answered on 

 the basis that there are many problems -- 

 technological and economic --that up to now 

 have prohibited the use of underutilized fish 

 for fish-block production. 



Investigations are now underway by the 

 U. S. Department of the Interior's Bureau of 

 Commercial Fisheries that are aimed at pro- 

 ducing suitable fish blocks from sheepshead 

 and burbot fillets. These studies are being 

 conducted by the Bureau's technological lab- 

 oratory at Ann Arbor, Mich., in cooperation 

 with processors from the Lake Superior and 

 Lake Erie fisheries. 



Sheepshead poses the more difficult task 

 for several reasons--rancid off -flavors de- 

 velop in the product during frozen storage; 

 sections of dark brownish-red flesh degrades 

 the appearance of the portions; and in some 

 instances, the texture of sheepshead portions 

 is hard and tough. Studies to control those 

 detrimental factors are proceeding quite well. 

 Sheepshead blocks processed under several 

 different conditions, aimed at controlling 

 these factors, are being prepared. The blocks 

 from the studies that appear acceptable for 

 commercial use will be taken to experienced 

 industry members for further evaluation. 



Very little is known about the frozen stor- 

 age characteristics of burbot. Therefore, in 

 addition to investigating the physical and ini- 

 tial quality characteristics of blocks made 

 from burbot, the expected shelf life of frozen 



portions cut from burbot blocks is being de- 

 termined. 



Great Lakes Fisheries Explorations 

 and Gear Development 



LAKE MICHIGAN TRAWLING 

 STUDIES CONTINUED: 



M/V " Kaho " Cruise 31 (March 2 9 -April 

 28): A 31 -day exploratory fishing cruise in 

 Lake Michigan was completed April 28, 1966, 

 by the research vessel Kaho of the Bureau of 

 Commercial Fisheries, U. S. Department of 

 the Interior. The cruise was conducted in 

 two phases to study and document the inshore 

 spawning migration of alewives. The first 

 phase was from March 29 to April 7 and the 

 second phase from April 19-28. The survey 

 covered the portions of Lake Michigan from 

 Ludington, Mich., to Two Rivers, Wis., south- 

 ward. The characteristics and timing of the 

 runs are of extrerae importance to the newly 

 developing Lake Michigan industrial fisheries 

 which now supply both pet -food manufacturers 

 and fish-meal reduction plants. The informa- 

 tion will also help lakeside municipal and in- 

 dustrial water users cope with alewife spawn- 

 ing migrations which create problems at Lake 

 Michigan water intakes. 



During the first phase of the cruise no evi- 

 dence of the shoreward spawning run was 

 noted and the alewives still characteristically 

 occupied deep water (beyond 45 fathoms). On 

 the second phase the spawning run had begun 

 along the shore from Saugatuck clockwise to 

 Two Rivers (the northernmost port visited). 

 Evidence from previous years that the spawn- 

 ing run follows a northeast lag in Lake Michi- 

 gan was verified during this study; that is, the 

 fish appear to begin to move shoreward first 

 in the extreme southern portion of the lake. 

 Thereafter, fish begin to move inshore at suc- 

 cessive locations northward and appear ear- 

 lier on the west shore than at corresponding 

 locations on the east shore. At the termina- 

 tion of the cruise, fish were heavy along the 

 entire west shore but had only reached Sauga- 

 tuck on the east shore. During the second 

 phase, catches were very heavy along the lake 

 from Benton Harbor clockwise to Two Rivers. 

 In that area, hourly catch rates of 6,000 to 

 180,000 pounds were made at or near all ports 

 visited. 



