A PLAN FOR PROMOTING THE WHITEFISH PRODUCTION 
OF THE GREAT LAKES. 
a 
By 8S. W. DOWNING, 
Superintendent U.S. Fisheries Station, Put-in Bay, Ohio. 
& 
In discussing this subject it will first be necessary that we understand 
something of the habits and the manner of reproduction of these fishes, and the 
probable increase and losses in numbers under natural conditions. Since the 
same conditions exist and the same reasoning will apply to all the lakes of the 
chain, we will confine our remarks to the conditions in Lake Erie. 
BREEDING HABITS AND NATURAL REPRODUCTIVITY OF WHITEFISH. 
The adult whitefishes are migratory, leaving the lower end of the lake and 
the deeper waters each year as the spawning season approaches and the breeding 
instinct prompts them, and seeking their natural spawning beds, which consist 
of the reefs among the islands and the rocky and sandy bottoms of the shoaler 
portions of the lake. Most of these reefs and shoals are of that peculiar forma- 
tion called honeycombed rock; that is, instead of being gravelly or smooth these 
rocks are dotted with holes and small cavities into which the eggs, as they are 
voided by the fish, may drop and be comparatively safe from being eaten by 
the suckers and other spawn-eating fishes, water lizards, or other enemies, and 
also from being covered by mud, silt, and other filth, and smothered, as they 
would be if deposited on mud bottom. 
Were the whitefish nest builders, and did they pair as some of the other 
fishes do so as to perform the function of fertilizing their eggs with any degree 
of certainty, the chances for a large production of young under such favorable 
conditions would be very good, indeed; but they are not nest builders, neither 
do they mate; on the contrary they approach the spawning grounds singly and in 
schools, and are what is known as ‘‘school spawners,’”’ the female extruding her 
eggs wherever she may happen to be, regardless of whether there is a male fish 
within close proximity or not. In consequence but very few of the fish come 
together so as properly to perform the functions of fertilization; and when it is 
629 
