The use of refrigerators, to retard the development of the egg until such time as it is most convenient to take care of the fry, is now extensively practiced in the United States, and has been experimented upon in Germany.
In the discussion of fish-cultural economy, the distinction between private fish culture and public fish culture must be carefully observed, and it must also be borne in mind that by public fish culture, or modern fish culture, I mean fish culture carried on at public expense, and for the public good. Public fish culture, to be effective, must be conducted by men trained in scientific methods of thought and work.
The distinction between private and public fish culture must be carefully observed. The maintenance of ponds for carp, trout, and other domesticated species, is an industry to be classed with poultry raising and bee-keeping, and its interest to the political economist is but slight.
The proper function of fish culture is the stocking of the public waters with fish in which no individual can claim the right of property.
The comparative insignificance of the private fish-culture of Europe is, perhaps, what has led to the recent savage attack upon fish culture in general by Malmgren of the University of Helsingfors. European fish culturists have always operated with small numbers of eggs. The establishment of Sir James Maitland at Howieton, near Stirling, Scotland, is the finest and largest private establishment in the world, and yields a handsome addition to the revenues of its proprietor. A description of this hatchery is published as one of the conference papers of the International Fisheries Exhibition, and that the distinction between public and private enterprise in fish-culture may be understood, it should be compared with the following statement by Mr. Livingston Stone, the superintendent of one of the seventeen hatcheries supported by the United States Fish Commission—that on the McCloud River in California.
“In the eleven years since the salmon-breeding station has been in operation, 67,000,000 eggs have been taken, most of which have been distributed in the various states of the Union. Several million, however, have been sent to foreign countries, including Germany, France, Great Britain, Denmark, Russia, Belgium, Holland, Canada, New Zealand, Australia, and the Sandwich Islands.
“About 15,000,000 have been hatched at the station, and the young placed in the McCloud and other tributaries of the Sacramento River. So great have been the benefits of this restocking of the Sacramento, that the statistics of the salmon fisheries on the Sacramento show that the annual salmon catch of the river has increased 5,000,000 pounds each year during the last few years.”
In the two government hatcheries at Alpena and Northville, Michigan, in the winter of 1883-84, there were produced over 100,000,000 eggs of whitefish, Coregonus clupeiformis, and the total number of young fish to be placed in the Great Lakes this year by these and the various state hatcheries will exceed 225,000,000. The fishermen of the Great Lakes admit that but for public fish culture half of them would be obliged to abandon their calling.
Instances of great improvement might be cited in connection with nearly every shad river in the United States. In the Potomac alone the annual yield has been brought up by the operations of the Fish Commission from 668,000 pounds in 1877 to an average of more than 1,600,000 in recent years.