GREAT LAKES COREGONIDS 



487 



winter through the ice, and also to some extent in the fall. They are used in many 

 localities also where the run of herring is not heavy enough to warrant the placing 

 of pounds. The size of the mesh of gill nets employed varies from 2y$ to 2% inches, 

 depending on the various State laws. Pound nets for herring are commonest in the 

 Green Bay district, but a few are employed at various points along the shore line of 

 every State bordering on the lake. In Green Bay of late years some have been 

 operated in the winter. 



SEASONAL MOVEMENTS 



The herring schools are ashore both in spring and fall and in many places they 

 probably stay near shore all winter. The schools are more or less pelagic, and their 

 movements probably are influenced materially by the food supply, but it is interesting 

 that they do not approach the shore when the water there is warmest. 



Data on occurrence in the herring nets in spring and fall. — In Green Bay, according 

 to R. F. Kleinke, the herring are found near shore as soon as the pound nets can be 

 put in in April or May. After June they disappear from the shores but return in 

 some numbers about the middle of September. They increase in abundance until 

 the spawning time during November, and then they leave until the ice forms, when 

 they are taken frequently under the ice. They are said to move erratically in the 

 winter and frequently are absent from the netting grounds entirely for some days at 

 a time. The 'deep-water form, which is taken most commonly in summer in the 

 bay at depths of 10 to 18 fathoms, is said by some fishermen to be found there all the 

 year round except when it comes ashore in November to spawn, while others maintain 

 that it occurs in these depths only during the summer months. It is probable that 

 all the fishermen have a basis for their statements, but that the first group catches 

 chubs among the herring at certain seasons and are not able to distinguish them. It 

 is certain that the catches examined by me on August 16, 1920, made in 11 to 16 

 fathoms between Green Island and Little Sturgeon (records 1 and 2), consisted exclu- 

 sively of herring; and as the lake's heat budget was near its maximum at this season, 

 it is clear that the fish found tolerable conditions at that depth in summer. Reasoning 

 from analogy on the basis of the behavior of herrings elsewhere and of other core- 

 gonids, it is to be expected that they would move into shallower water as the waters 

 cooled. At Port Washington, Wis., Delos Smith says the herring are found in the 

 pound nets in 20 to 60 feet as soon as they can be set in April. The runs are heaviest 

 in May, and by July 1 they are over. Occasionally a school comes into the nets in 

 summer, but there is no herring fishing of consequence until after September 15. 

 During October and early November the runs are at their height. The fall run, 

 Mr. Smith states, consists of larger fish. At Milwaukee, Wis., George and Fred 

 Tilly find the herring in 8 fathoms during April and May in gill nets, and again in 

 October and November. At other times they pursue more valuable fish. Record 

 15 was made from the net of the Tilly brothers and shows that herring were caught 

 in 10 to 15 fathoms off Milwaukee on March 24, 1919. F. C. Kimball, of Michigan 

 City, Ind., says that the herring are found as soon as the pound nets are put in in 

 April at depths of 18 to 30 feet on sand bottom. There are good lifts until early 

 May. After that the schools are erratic in their movements and come ashore only 

 when favorable currents have coo'ed the shore waters. In October the lifts are 

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