THE WHITEFISH PRODUCTION OF THE GREAT LAKES. 655 
the river in schools. They were never found in this portion of the river in the spawning 
season. 
The same fact is claimed by the Indians in the Sault Ste. Marie River, that the 
whitefishes of the lake above never descend the rapids, while the whitefishes of the river, 
it is also asserted, never ascend to Lake Superior. There is not as good evidence for the 
truth in this locality as at Fort Gratiot; still it may be the case. 
The evidence collected by Rathbun and Wakeham points also to the local 
habit of the whitefish of Lake Ontario. They say (p. 60): 
There does not seem to have been any regular migration of these fish lengthwise of 
the lake. They occurred along a narrow border of the lake and simply moved to feeding 
grounds in the spring and to spawning grounds in the fall wherever the shoal water was 
suitable. There they were most abundant, and on these areas we still find the remnant 
of them. 
Again they say of Lake Huron: 
The movements of the whitefish in Lake Huron are, in general, less definite than in 
Lake Erie, being confined to shoreward migrations in the spring and fall. These 
migrations appear to be accompanied by no extensive progress alongshore, except at 
Detour, where the spring run is said to have a general easterly direction, appearing first 
near Detour and then passing down the North Channel into Georgian Bay. 
It would be easy to compile evidence from the statistical returns of the 
Michigan fish commission to show the local habit of the whitefish, from the fact 
that fisheries have often been depleted in one locality while remaining profitable 
in other localities 25 to 50 miles distant, but the facts already cited seem to 
be sufficient for the purpose. 
WHITEFISH AREAS OF GREAT LAKES. 
An examination of the whitefish areas as platted on the accompanying maps 
tends to strengthen this view of the local habit of the whitefish. In Lakes 
Superior, Ontario, and Michigan we see this area stretching in a relatively narrow 
zone along the whole shore. This zone incloses a central area of deeper water 
which separates the whitefish area of one side of the lake from that of the other 
side and is probably never crossed by these fish. Within it occur the blackfins 
and longjaws. In Lake Huron we see a similar condition of affairs for the main 
lake, but in Georgian Bay we find the greater part of the area taken up by white- 
fish grounds. Here the deep water is not central in the whitefish area but is 
displaced toward the southwest so as to leave the marginal whitefish area very 
narrow on one side of the lake and very broad on the other side. In the North 
Channel of Lake Huron a continuous whitefish area occupies its center uninter- 
rupted by a deeper middle water. In this lake the reef which cuts obliquely 
across the main lake is said not to harbor whitefish in commercial quantities 
and not to afford them spawning ground. It is therefore not included in the 
whitefish area, although of suitable depth, and its extent is indicated on the map 
in outline only. 
