GREAT LAKES COREGONIDS 



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grounds in the spawning season. The catches during the spawning season are the 

 heaviest, though at other seasons some quantities of whitefish are taken also; but 

 the catches at other times are mixed with trout usually, and few fishermen could 

 operate large-meshed gill nets if they were dependent on their catches of whitefish. 

 Elsewhere in the lake there are now virtually no spawning grounds where numbers 

 of whitefish can be gilled, and the whitefish thus taken are stragglers among the 

 trout. The pound nets in the north depend for their success largely on the white- 

 fish, though in Grand Traverse Bay rough fish, trout, etc., are a considerable factor 

 in the profit of the fishermen. In other parts of the lake whitefish are chiefly of 

 lesser importance because of their relative and absolute scarcity, and the pound 

 nets are found profitable on account of the variety of fish taken and the better price 

 that can be realized for the rough fish, due to proximity to the markets. 



There is a notion widely current over the Great Lakes, based on the observa- 

 tion that gill nets do not take whitefish successfully in shallow water; that there are 

 two kinds of whitefish, one of which will lead into the pound net and one that will 

 gill only. An exposition of the principle on which the two types of apparatus depend 

 for effectiveness affords an explanation for this belief. In Lake Michigan pound 

 nets are fished only from shore to depths of about 50 feet, due to the expense of 

 splicing the stakes used in holding the pots in deeper water. In Lake Huron nets 

 sometimes are set to 90 feet, but for the most part all pounds everywhere on the 

 Great Lakes are set within the first-named limit. In this shallow water, in the 

 daytime at least, the netting is probably always visible to the fish, and the success 

 of the pound net is due to the ability of the fish to detect the presence of the netting 

 and to avoid it. Thus, when the fish encounter the leads of the pounds (which, by 

 the way, are usually coarse enough to permit them to swim through them), some, 

 at least, follow them and thus eventually find themselves in the pot, from which 

 there is little chance of escape. If they did not sense the presence of the lead they 

 would swim through it. The hordes of herring and other small fish that often fill 

 the pots in summer and that remain in the pot until, on lifting, they are frightened 

 through its meshes, illustrate the tendency of fish to keep free from contact with 

 the netting. The success of the gill net, on the other hand, depends on its being 

 unobserved by the fish, else the fish would follow along the meshes and not become 

 gilled. Thus, the effectiveness of the gill nets probably declines directly as that of 

 the pounds increases, and therefore gill nets are not successful in shallow water. 

 Even in deeper water many of the gill-net fishermen believe that their lifts are heavier 

 in the dark of the moon, while many pound netters expect better catches in the 

 light of the moon. At times when gill nets make good catches in shallow water 

 (namely, during the spawning season) the fish may enter the nets in the excitement 

 of the mating act. 



SEASONAL MOVEMENTS 



Like the rest of the coregonids, the whitefish travel in schools, as shown by the 

 fact that a gang of gill nets may catch all its whitefish in one or two boxes of nets, 

 or by the fact that only one pound of half a dozen in the same neighborhood may 

 take the fish. Many fishermen claim, also, to have seen these schools along the 

 shores. The schools, it appears, are local in their habits and do not wander over 

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