178 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
The information presented in this paper includes a brief account of the physical 
characteristics of the lake as far as they may have influence on the fish and fisheries; 
statistics showing the extent of the commercial fisheries in each county on the lake, 
-with a consideration of the present and past importance of the lake fisheries ; an exhi- 
bition of the extent of the import trade in Canadian fish, with a discussion of the same; 
remarks on certain fishes of economic importance; and a suggestion of the steps nec- 
essary for the improvement of the fisheries. 
PHYSICAL CHARACTERISTICS OF LAKE ONTARIO. 
A thorough study of the physical conditions of Lake Ontario is necessary for and 
must antedate a comprehensive knowledge of the fish fauna. Temperature, depth of 
water, character of bottom, currents, winds, and sediment all have important bearings 
on the movements, habits, and abundance of fishes. Unfortunately, such an investi- 
gation has never been undertaken, and it is only nossible to present a few facts having 
a general application. 
Ontario is much the smallest of the Great Lakes. Its maximum length is 185 miles, 
and its greatest width, opposite Irondequoit Bay, is 55 miles; the average breadth is 
about 40 miles. The area is about 6,500 square miles, of which some 2,700 square miles 
are within the jurisdiction of the State of New York, and the remaining portion is 
controlled by the government of Canada. The province of Ontario occupies the entire 
northern and western and a part of the southern shores, leaving only the eastern por- 
tion of the southern side abutting on New York. The shores, following the major 
indentations, are 565 miles in length, of which New York occupies about 265 miles. 
The surface of the lake is 232 feet above the level of the sea, although the mean 
level is subject to considerable variation within limits which are necessarily somewhat 
narrow. In 1891 the surface of the lake was lower than for many years, and toward 
the end of the season was said to be fully 3 feet below the mean level. This was due 
in a measure to the small quantity of water brought down by the tributary streams, 
and also to the reduction in the supply coming from the upper lakes. Persons familiar 
with Niagara Falls were heard to comment on the diminution in the amount of water 
passing through the river basin at certain periods during the summer. 
Lake Ontario has a much greater average depth than the adjoining member of the 
chain, Lake Erie ; this feature is of considerable importance in connection with the 
movements and distribution of fish. The eastern end of the lake is much the shallowest 
portion, the western extremity is somewhat deeper than the eastern, while the deepest 
water is found near the middle of the lake in the region of its greatest width. That 
part of the lake which is below or to the north of the chain of small islands, extending 
from Stony Point on the east to South Bay Point on the west, and which contains the 
most important fishing- grounds for whitefish, trout, and pike perch, varies in depth 
from 30 to 180 feet, and has an average depth of about 100 feet. A number of small 
shoals occur which serve as spawning-grounds for whitefish and trout. One of the 
most important of these is Charity Shoal, situated 6 miles west of Grenadier Island, 
which is the ground most resorted to by the trap-net fishermen of Jefferson County. 
In the middle and western portions of the lake the water, toward the middle, has a 
depth varying from 200 to over 700 feet, the average being about 400 feet. The deepest 
soundings made by the engineer corps of the U. S. Army were 13 miles from the 
American shore in a direction NNW. from Sodus Point; here the water was 738 
