PROGRESS IN BIOLOGICAL INQUIRIES, 1926 593 
an era of exploitation of both fresh and salt water fishes, the extent and 
intensity of which, on the basis of past experience, is beyond our ability to 
estimate. The one great outstanding problem of the fisheries, therefore, over- 
shadowing all others in fundamental importance, is that of maintaining an 
abundant supply. The time has passed when our fishing grounds may be 
extended and new reserves drawn upon suflicient to meet the demand. The 
only hope of the future lies in the wise husbanding of our present resources. 
It is, therefore, clearly the duty of the Bureau of Fisheries, in the fifty- 
seventh year of its activity, to return to the faith of the fathers and, in the 
words of Spencer F. Baird, to ascertain what diminution in the number of 
food fishes of the coast and lakes of the United States has taken place, to de- 
termine what are the causes of the same, and to suggest any measures that 
might serve to remedy the evil. An official of the Bureau of Fisheries has 
made the profound discovery, the honor for which I am sure he will share 
gladly with hundreds of codiscoverers, that the real cause of the deterioration 
of our fisheries is the lack of adequate regulation! This discovery is valuable 
as the basis for an excellent alibi, for the fisheries are the property of the 
States and are under their sole jurisdiction, hence the responsibility for the 
decline rests upon the State governments, which have permitted excessive de- 
struction and wasteful methods of fishing to continue unabated. It means more 
than that, however. It epitomizes the changed attitude toward the all-suffi- 
ciency of fish culture in maintaining the fisheries. 
Of course, the announcement of this discovery does nothing more than define 
the responsibility, for the lack of adequate regulations is the result of inade- 
quate knowledge concerning the proper methods of conserving the fish supply 
and public apathy, in some localities, toward making use of the knowledge 
already had. In its role as advisor to the States, it. is the duty of the bureau 
to determine the variations in the supply of commercial fishes and the factors 
that regulate their abundance, and to encourage the application of this knowl- 
edge to their protection and wise use. While fishes have been studied hereto- 
fore as individuals, they must now be studied as species or as natural units— 
populations that inhabit limited areas. A fisheries science must be developed 
comparable to the science of vital statistics—an idea advanced by Dr. Johan 
Hijort before the International Council for the Study of the Sea in 1907.% 
As he pointed out, the three most prominent factors affecting populations are 
birth rate, age distribution, and migration, and these must receive our first 
attention. 
While an intimate knowledge of the life history of the commercial species of 
fish must always be the basis of every attempt at conservation, the husbandry of 
fish must depend upon other information, chief of which is an accurate knowl- 
edge of changes in the abundance of the fish stock. The fishery itself must be 
studied therefore, together with the effects of fishing effort upon the stock, in 
order to gauge the increase or decrease in avdilable supply and to discover if 
these changes are due to natural causes over which man can hope to have but 
little control, or to overfishing, and therefore subject to regulations. Effective 
fish husbandry must further take into account the proper regulation of the 
fishery, so that the yield may reach its maximum without encroaching upon 
that reserve of spawning stock upon which the future must depend. Another 
phase of fish husbandry, and which applies to inland waters, is concerned with 
fish farming. Metheds of propagation, of cultivation, and of management must 
be devised to supplement and increase the productivity of natural waters and 
to make fruitful the barren areas wherever possible. 
To summarize: 1. The bureau must assume part of the responsibility for 
maintaining and building up the commercial fisheries, and its investigations 
must be directed toward that end. 
2. It must actively encourage the States to do their part in gathering statis- 
tics and cooperating in investigations. 
3. The bureau’s investigations of commercial fisheries must include observing 
and describing the composition of the catch and the fluctuations in supply, as 
indicated by reliable criteria of abundance. Natural fluctuations must be dis- 
tinguished from depletion resulting from man’s activities. 
4. The life histories, migrations, and ecological relations of the principal 
species must be worked out to explain the fluctuations in the fish stock and, if 
possible, to control or foretell their occurrence. 
oa et St nes nag Dae as a a ee e e Pa: a 
14 Rapports et Procés-verbaux, Vol. XX. 
66552—28—_6 
