522 



BULLETIN OF THE BUREAU OF FISHERIES 



Reef and the Fox Island Reef are among the largest areas frequented by spawning 

 whitefish. The bottom varies with the locality and may be gravel, honeycomb 

 rock, or small stones. Sand or clay appear in general to be avoided now, though 

 when the species was commoner some individuals may have been forced to spawn in 

 such locations. The depth at which spawning takes place is from 1 to 10 fathoms, 

 according to the fishermen. Earlier in the season some of these grounds are used 

 as spawning places by the lake trout, but the whitefish do not spawn on all the trout- 

 spawning grounds. Possibly some have unsuitable bottoms, though the fishermen 

 do not know that there are differences between the trout grounds they visit and those 

 that they do not. 



Nothing definite is known of the spawning behavior of the whitefish, but several 

 fishermen from different localities say that during the breeding season they have seen 

 areas of the bottom on the spawning grounds cleaned of silt, such areas often being a 

 square foot in extent. Whether these spaces actually are cleaned as sites for the eggs 

 or whether they are the result of the body movement of the fish while spawning is not 

 known. That the fish spawn by jumping out of the water, as has been described for 

 pen fish, has been observed by no one anywhere on the lakes to my knowledge; and 

 it is likely that these fish were trying only to escape from their pens, and, being 

 ripe, their violent movements forced the eggs out. 



The size of the whitefish at spawning varies with the locality. Among the largest 

 spawning fish are said to be those of Jo Smiths Reef northwest of Hog Island, while 

 those on the Fox Island Reef are among the smallest. It appears that the white- 

 fish in Lake Michigan begin to spawn while still small, and most fishermen have seen 

 individuals that were sexually mature at 134 to lM pounds in the round. Two male 

 specimens weighing 10 and 13 ounces, taken off Algoma, Wis., and South Manitou 

 Island late in July, were sexually mature. Scale examinations show, however, that 

 these fish are in their fifth year and therefore are dwarfs. Study probably will show 

 that maturity is a question of age rather than of size. 



VALUE AS FOOD 



The flesh of the whitefish brings a price, on the market, greater than that of 

 any other lake fish except the sturgeon. Its value as food has been recognized fully 

 since its existence in the lakes has been known. 



ABUNDANCE 



In consequence of its food value, the whitefish, in the earlier days, was sought 

 for the markets with the aid of every device that human ingenuity could invent. At 

 no season was the pursuit relented, and no fish were too small to be taken. The 

 smallest, together with the herring and the sturgeon, often were carried out onto the 

 beach because they were so numerous that they interfered with the capture of the 

 larger whitefish. Though originally whitefish were found in incredible abundance all 

 along the shores of the lakes (in fact, it is said that the species was the predominant 

 one on the shoals), they could not endure long such drains on their numbers. Where 

 for 1880 the Federal statistics show a production in Lake Michigan of over 12,000,000 

 pounds of whitefish, the catch for 1922 is given as a little over 1,500,000 pounds, 



