14 U. S. BUREAU OF FISHERIES 



Although not all are agreed as to the best methods for providing 

 conservation, it is appreciated that to be effective they must rest on 

 a firm foundation of scientific information. R-egulatory laws 

 limiting the season in which fishing may be carried on or the type 

 of gear that may be used must be formulated in the light of a 

 knowledge of the biology of the various species of fish that form the 

 basis of the fisheries in question. Artificial propagation must also 

 he regulated through a knowledge of these factors, and informa- 

 tion must be secured as to the causes affecting, adversely or other- 

 wise, the development, survival, and growth of the eggs and young 

 fish. It is the office of the division of inquiry to provide such data 

 as these, upon which adequate regulations and effective propagation 

 may be based. 



It is always difficult to draw the line between scientific investi- 

 gations of practical application and those of purely academic inter- 

 est. Probably few investigations in pure science are without their 

 ultimate practical application, and likewise few investigations de- 

 signed primarily to solve practical problems are without their 

 bearing on the problems of pure science. This applies with peculiar 

 force to fishery problems, and to provide an adequate and compre- 

 hensive program for fishery research is a difficult task. In general 

 fishery problems are exceedingly complex. Aside from the influence 

 of man, the relative abundance of fishes depends upon the relative 

 abundance of the smaller aquatic plants and animals that form their 

 food and of the numerous enemies that prey upon them from the 

 time the eggs are laid until maturity. Again, the abundance of 

 these smaller forms is directly dependent upon other factors — tem- 

 perature, etc. — and in the ocean currents play an extremely important 

 part in the distribution of the eggs and of the very young fish. 

 Yet to the average layman the investigation of such things as 

 oceanic currents, the temperature and salinitj' of sea water, and the 

 microscopic life of both the sea and fresh-water streams and lakes 

 may seem far removed from the legitimate purposes of fishery in- 

 vestigations. This is far from being the case, however, and any 

 coniprehensive plan for fishery investigations must involve studies 

 of this character. 



Just what is meant by conservation? This much-abused word 

 does not mean merely saving, although it is probable that to most 

 persons the two words are sjmonymous, for we might save the fish- 

 eries without conserving them in the true sense. They might be 

 saved by prohibiting all fishing, but this would not be conservation. 

 To conserve means rather to guard and protect the resources so that 

 depletion may not occur and that the}' may continue indefinitely to 

 provide food for man. It may be said that the conservation of a 

 fisher}^ resource involves as much its utilization to the fullest pos- 

 sible extent compatible Avith its perpetuation as it does the preserv- 

 ing of the resource against undue exploitation. The care of the 

 fisheries has not been developed to the stage of perfection reached 

 in the care of the important agricultural products, but advances 

 have been and are being made in spite of the fact that in many ways 

 the problems are more difficult, since most fish can not possibly be 

 reared to maturity under the control of man. There is no reason 

 to suppose, however, that the husbandrj^ of fishery resources maj' 



