526 



BULLETIN OF THE BUREAU OF FISHERIES 



Data from the pound nets. — In Table 86 are assembled statements on the occur- 

 rence of the whitefish in the pound nets set out of various ports on Lake Huron. As 

 might be expected over so wide an area, the movements of the fish vary from port to 

 port. It appears that the fish are often on the grounds in shallow water as soon as 

 the nets are put in in the spring (Point Au Gres, Port Huron, Blind Kiver, Thessalon, 

 Gore Bay, and Cockburn Island). At Killarney the fish are said to be on the shoals 

 when the ice leaves. At a depth of 65 to 75 feet the nets get them only as they 

 move out toward the last of May. The heaviest runs usually are over by the first part 

 of July in the nets set in less than 45 feet (East Tawas, Point Au Gres, Port Huron, 

 Blind River, Thessalon, Gore Bay, Kagawong, and Wiarton). In the nets at 45 to 

 75 feet off Providence Bay and Killarney and in the 30 to 45 foot nets off Cockburn 

 Island and the Duck Islands the heaviest runs appear from June and July (for 

 Killarney) to August and September (for Providence Bay and Cockburn). The fish 

 are absent entirely in all the nets in 25 to 45 feet of water during August and in some 

 localities earlier (Alpena, East Tawas, Point Au Gres, Port Huron, Blind River, 

 Thessalon, Gore Bay, Kagawong, and Wiarton). At Cockburn Island, the Duck 

 Islands, and Killarney the fish may remain all the summer. The schools return in 

 the fall between the first part of September and the last of October. 



Data from gill nets. — The number of whitefish caught in gill nets has decreased to 

 such an extent that few fishermen could operate if they were dependent on their 

 catches of whitefish. Almost every port, however, takes some whitefish in gill nets 

 during the year. The most successful catches, the fishermen say, are those made on 

 mud or gravel bottom. The nets usually are set in the early spring at 10 to 15 fathoms, 

 except off Alpena, where the whitefish are found in April in 30 fathoms, the maximum 

 depth from which the species is known in the lake. The biggest catches are made in 

 15 to 20 fathoms during July and August. In September the nets are moved into 

 shallower water again, and in October and November the spawning run is taken on 

 the shoals. A few whitefish are taken through the ice in 10 to 20 fathoms off Thessalon 

 and Gore Bay. 



The fish caught in the gill nets are smaller, as a rule, than the pound-net fish. 

 Certainly few jumbos (fish over 4 pounds) are caught in the gill nets in summer, 

 while they may be common in the pounds. This fact and the fact that gill nets set 

 in shallow water take few fish have led some fishermen to assert that there are two 

 kinds of whitefish. Neither statement can be disproved. An explanation for absence 

 of fish in gill nets in shallow water has been suggested already. As for the former, it 

 is probable that the 4^-inch mesh is too small for the larger fish. 



The data from the gill nets on the movements of the whitefish agree with those 

 from the pound nets. In spring and summer the fish are found by the gill nets in 

 10 to 15 fathoms when the main schools are in 45 feet (about 8 fathoms) or less. 

 Then when the fish move to deeper water in July and August the pound nets in 

 45 to 75 feet get them best and the gill nets make their biggest chatches in 15 to 20 

 fathoms. In the early fall the fish move inshore again and are taken first by the 

 pound nets and later, when they are spawning, by the gill nets. In most localities 

 they probably remain on the shoals under the ice. There are several facts that 

 support this statement: (1) Some fish are caught under the ice in the North Chan- 

 nel; (2) the nets at Point Lookout in Saginaw Bay get the fish as soon as the ice 



