GREAT LAKES COREGONIDS 



495 



pass out; but they escape only when the pot is lifted. When it is desired to retain 

 herring in the pounds the mesh of the pot must be reduced to about 2 inches. When 

 gill nets are used (which is chiefly in the fall, when the fish are most abundant) the 

 mesh in to 2^ inches, or even 3 inches, depending on the locality. The ques- 

 tion of the mesh that should be legal for herring has been much agitated. The 

 fishermen claim that the herring always run small out of certain ports and that for 

 this reason at these ports nets of smaller mesh are required. I have been able to 

 collect no data on this subject, but I believe that probably there is no reason to doubt 

 the statement of the fishermen. 



SEASONAL MOVEMENTS 



Like the whitefish, the herring schools move inshore in the early fall and out 

 again in late spring. It is possible that for some localities, at least, there are two such 

 movements — that the fish come in and go out both in fall and spring instead of 

 remaining inshore all winter. There are not yet enough data on winter fishing to 

 decide this point. To what these migrations are due has not been determined, but 

 the fishermen believe that they are governed by changes in water temperature. 

 The data collected from the fishermen bearing on these migrations all indicate that 

 this explanation is at least plausible. These data are summed up in the following 

 paragraphs : 



Data on occurrence in the herring nets in spring and fall. — At Cheboygan, Mich., 

 according to Louis Peets, the herring are in 20 feet of water on sand bottom from 

 the middle of October until he pulls in his pounds (the last of November). In spring 

 he finds them on these grounds again, but in diminished numbers. They remain 

 until about June. Alfred Roberts says the behavior of the species is about the 

 same at Harbor Beach, Mich. During June, however, when the main school has left, 

 a school of larger herring comes in. These fish gill in 2^-inch nets, while for the 

 others 2 to 2% inch nets are required. The large fish come in, the fishermen think, 

 to feed on the "June flies," which are present in swarms at that time of the year. 

 The June fly, from the description of the fishermen, seems to be a large Chironomus. 

 Bert Andrews, of Port Huron, Mich., gives the following account of the species for 

 that port: 



"From the opening of navigation (April 1) until the end of June, and from the 

 middle of October until ice forms, herring are taken out of Port Huron in pound nets 

 in 25 feet of water. The largest numbers are caught from November 10 to the end 

 of the month. Some are taken in 20 feet of water in gill nets all winter." At Middle 

 Island and in Thunder Bay, from the middle of October until freezing, the Alpena 

 and Rogers boats (according to the statements of the pilots of these boats) set 

 2%-inch gill nets in 3 to 5 fathoms on gravel and bowlders. If conditions are favor- 

 able, the Alpena tugs set the nets back for a few lifts toward the end of March or 

 the first of April. Records of James Morley show that about the middle of May 

 the herring begin to come into the pound nets in 25 feet of water about Sulphur 

 Island. They are gone from the end of July to the end of September. From the 

 end of September until the nets are pulled out (in the middle of November) they 

 are present again. The quantity taken at Sulphur Island is not great. Records 

 94995—29 14 



