LAKE HERRING OF GREEN BAY, LAKE MICHIGAN 



133 



MOVEMENTS AND ACTIVITY 



Available evidence shows that the lake herring, 

 as well as other coregonids in the Great Lakes, 

 does not undergo extensive migrations. Principal 

 source of information is the study of Smith and 

 Van Oosten (1940), who reported the following 

 percentage recaptures from Lake Michigan fish 

 tagged from 1929 to 1931 near Port Washington, 

 Wis.: 5.4 percent from 593 lake herring; 22.1 

 percent from 457 whitefish; 5.7 percent from 106 

 chubs {Leucichthys spp., other than lake herring); 

 and 20.0 percent from 35 pilots, or round white- 

 fish {Prosopium cylindraceum quadril late rale). 

 Lake herring were not recovered at distances 

 greater than 50 miles from point of tagging, while 

 lake trout and rainbow trout tagged in the same 

 study were recaptured at distances as great as 125 

 to 225 miles away. The percentage distribution 

 of recoveries was as follows: 



Jarvi's (1920) study of the "kleine Marane," a 

 species similar to the lake herring, in Keitelesee, 

 Finland," disclosed the presence of distinct stocks, 

 with respect to growth and age composition, in 

 different basins. In view of these differences he 

 concluded that the movements of the "kleine 

 Marane" must be limited and that the few ob- 

 served migrations probably resulted from unusual 

 temporary conditions. 



Local movements of the lake herring that have 

 been observed probably are the result of thermal 

 conditions or represent spawning and feeding ac- 

 tivities. The vertical movement accompanying 

 thermal stratification is not as great as the hori- 

 zontal distances that must be traveled in Green 

 Bay when the fish abandon the .warming shallow- 

 water areas to seek colder water. This distance 

 amounts to about 10 miles in northern Green Bay 

 and 25 miles in southern Green Bay. Similar dis- 

 tances are covered in the return to shallow-water 

 areas prior to and accompanying spawning. In 

 Lake Erie the summer and spawning movements, 

 according to the distribution described by Van 



" The greatest length of Keitelesee Is 72 kilometers, or about 45 miles. 



Oosten (1930) must involve distances of 100 miles 

 or more. 



Cahn (1927) found that theciscoes of Oconomo- 

 woc Lake were closer to the surface at night than 

 during the day, and he interpreted this diurnal mi- 

 gration as a feeding movement. Jarvi (1920) ob- 

 served the same diurnal movement in the "kleine 

 Marane" of Keitelesee. He believed that the local 

 horizontal movements of schools of "kleine Ma- 

 rane," as well as the diurnal movements, were asso- 

 ciated with feeding. Similar movements of lake 

 herring schools in Green Bay are shown by the 

 highly erratic catches of nets fished in the same 

 locality day after day. A good example is found 

 in the catches at Sister Bay on December 2, 3, 

 and 4, 1950, where a pound net apparently took 

 members of three different schools on three suc- 

 cessive days (see p. 126). 



There is some evidence that the strong currents, 

 which are common in Green Bay, are responsible 

 for movement of lake herring. These movements 

 are reported by commercial fishermen who occa- 

 sionally, following summer storms, take lake her- 

 ring in shallow-water areas where they are not 

 normally found during the summer period. These 

 occurrences indicate that lake herring can be trans- 

 ported by currents. 



SUMMARY 



1 . The lake herring occurs in many of the deeper, 

 colder lakes of the northeastern section of the 

 United States, over most of Canada and Alaska, 

 and also in Hudson and James Bays. It is rarely 

 found in rivers. 



2. Green Bay is one of the most productive com- 

 mercial fishing areas in the Great Lakes and the 

 lake herring is a major contributor to the total 

 catch in the bay. In 1952 Green Bay produced 

 38.7 percent of the total take of lake herring from 

 all United States waters of the Great Lakes. 

 The commercial catch fluctuates widely, but this 

 study was conducted during years (1948-52) when 

 production was high and relatively stable. 



3. Green Bay is 118 miles long and 23 miles 

 wide. Water exchange with Lake Michigan is rela- 

 tively free in the northern end of the bay, but prac- 

 tically nil in the southern section. Water move- 

 ments in the bay are complex and often are of 

 considerable magnitude. They result in an un- 

 stable, almost continually changing environment 

 within the bay. 



