August 1966 



COMMERCIAL FISHERIES REVIEW 



29 



"introduction of predatory species such as 

 the coho (silver) salmon, which will feed on 

 the trash fish that now dominate the lakes, 

 will benefit both sport and commercial inter- 

 ests. Although those species will be primar- 

 ily for sportsmen to harvest, their predatory 

 influence will help create conditions favorable 

 to commercial species as well," he explained. 

 ( News Bulletin , Michigan Department of Con- 

 servation, Lansing, May 26, 1966.) 



MICfflGAN PROVIDED WITH 

 SPLAKE BROOD STOCK FOR 

 LAKE HURON PLANTINGS: 



Approximately 6,000 ''super" splake finger- 

 lings were flown to Teal Lake near Ishpeming, 

 Mich., this past June by Canada's OntarioDe- 

 partment of Lands and Forests to provide 

 brood stock for fish plantings in Lake Huron 

 in 3 or 4 years, according to the Michigan 

 State Department of Conservation. 



The tiny fish, a highly selective strain of 

 the lake trout and brook trout, were taken to 

 the State of Michigan's Marquette fish hatch- 

 ery where they will be raised tq spawning 

 size. Young splake reared from the future 

 brood fish will then be planted in Lake Huron, 

 starting in 1969 or 1970. By that time, it is 

 expected that chemical treatment work in 

 Lake Huron streams will have made enough 

 progress to give the planted fish a relatively 

 good margin of safety from sea lamprey pre - 

 dation. The first-round fight to control lam- 

 preys in the lake's problem tributaries was 

 opened this spring. 



The splake were specially perfected by 

 the Canadian government agency to provide 

 planting stock for Lake Huron which will en- 

 joy high survival and reproduce several years 

 earlier than lake trout. 



Under a joint program to be carried out 

 by the Ontario agency and Michigan Depart- 

 ment of Conservation, this variety of splake 

 will be used exclusively for restoration plant- 

 ings in Lake Huron. Tentative plans call for 

 annually stocking the lake with several mil- 

 lion of the fish for at least 6 years. 



Ontario and Michigan fisheries officials 

 consider the splake to be much better a- 

 dapted to rehabilitating Lake Huron than 

 the lake trout which are being planted in 

 Lakes Superior and Michigan in large num- 

 bers. 



"We have been experimenting on selective 

 strains of splake for about 10 years and this 

 latest variety to be raised as brood stock here 

 and in Michigan is superior to the other ones 

 we have developed," reported the supervisor 

 of fisheries research for the Ontario Depart- 

 ment. 



"These fourth and fifth generations of se- 

 lective fish are specially adapted for deep 

 swimming and therefore will occupy waters 

 of Lake Huron where the lake trout formerly 

 lived," he added. The fish have also been de- 

 veloped for early maturity and reach a spawn- 

 ing stage in 2 or 3 years. By contrast, lake 

 trout do not mature until they are seven 

 years old. 



"This means," said the supervisor of fish- 

 eries research, "that our planting efforts will 

 be less expensive than they would be with lake 

 trout." Compared with lake trout, fewer sep- 

 arate age classes of splake will have to be 

 planted to insure sustained reproduction of 

 the fish, he explained. 



Ontario and Michigan fisheries officials 

 are highly optimistic that the splake planting 

 program will be a big success. ( News Bul - 

 letin, Michigan Department of Conservation, 

 Lansing, June 2, 1966.) 



Great Lakes Fisheries Explorations 

 and Gear Development 



SEASONAL DISTRIBUTION 

 AND ABUNDANCE STUDIES 

 OF ALEWIFE AND CHUB 

 IN LAKE MICHIGAN CONTINUED : 



M/V " Kaho " Cruise 32 (May 2-20, 1966): 

 To determine the distribution and measure 

 the relative abundance of alewife and chub 

 stocks, which provide raw material for new 

 pet food and animial food manufacturers, was 

 one of the objectives of this cruise by the 

 exploratory fishing vessel Kaho . The vessel 

 is operated by the Bureau of Commercial 

 Fisheries, U. S. Department of the Interior. 



Catches of alewife ranging from 3 tons in a 

 15 -minute drag to 4 tons in a 1 -minute drag ver- 

 ified the fact that this species is still on the in- 

 crease in Lake Michigan and that only a small 

 percentage of the areas yielding such catches 

 are being used by commercial fishermen. 



