632 BULLETIN OF THE BUREAU OF FISHERIES. 
and is paid for them at so much per quart for fertile eggs. These men operate 
gill nets and fish on the reefs, and as the whitefish do not frequent the reefs | 
to any extent until ready to spawn, usually more than 50 per cent of their 
catch is ripe fish. 
MEASURES NECESSARY TO INSURE INCREASED PRODUCTION. 
- From a practical experience of sixteen seasons in the hatching of whitefish 
and by consultation with other fish culturists, we find that the average hatch 
of the eggs collected and taken to the hatcheries is from 75 to 80 per cent. 
Assuming the lower figure to be the correct one, if each pair of whitefish, as 
previously shown, produce 35,000 eggs, by the assistance of the hatcheries 
we get three-fourths of 35,000 or 26,331 fry as against the 11 the same fish 
would have produced if the eggs had been left to themselves, or 2,393 times 
as many as it was intended by nature for them to produce, as just now shown. 
Even allowing that the whole of the 1 per cent naturally fertilized hatch, giving 
350 fry as the number produced by each pair of fish, the hatchery would still 
beat nature by 25,981 fry or 750 times as many, and the fry produced in the 
hatcheries are just as strong and vigorous and their chances for reaching maturity 
are just as great as are those hatched naturally. Then, if by the lower calcula- 
tion we produce 750 times as many fry by collecting the eggs and hatching 
them at the hatcheries as the fish would produce if left to themselves, it is 
obvious that the best plan to promote the whitefish production of the Great 
Lakes is: 
To so arrange matters that artificial propagation shall be generally applied 
to reproduction by having hatcheries established at every available point 
where a sufficient number of eggs can be secured to warrant their maintenance. 
It is not necessary that the hatcheries be operated on as large a scale as those 
at Detroit and at Put-in Bay, but wherever enough eggs can be secured to give 
a hatch of from 25 to 50 millions, if these points are remote from the larger 
stations put up a hatchery and operate upon as economical a scale as possible; 
to stock these hatcheries not only collecting the eggs from the ripe fish as caught 
by the fishermen, but penning and holding the green fish until they ripen, 
pursuing the method just described, so that practically all the fish caught will 
have contributed toward this production before being placed upon the market. 
To make this plan the more effective, so as to get the greatest increase 
possible from the fish caught, a law should be enacted compelling the fishermen 
to collect, or allow the hatcheries to collect, all the eggs from the ripe fish, 
and to place the green fish in the auxiliary nets for penning; the fishermen 
to be paid a fair price for the eggs so taken by them and for their trouble in 
penning the fish, and to receive a fair remuneration for all fish lost by penning. 
