24 REPORT OF THE COMMISSIOJ^ER OF FISHERIES. 



fishes and other animals of economic importance. Recently the A-ast deveIoi> 

 meut of petroleum production and transportation, the use of its derivatives for 

 manifold purposes ashore, and particularly as fuel on ships, has introduced a 

 new element of serious pollution in the great harbors and in places on the open 

 coast. 



The pollutions are almost as varied as industry and in many cases are not 

 only complex in tliemselves but are further complicated by their reactions on 

 one another and on tiie natural constituents of the waters themselves. The 

 waters can not be restored to tlieir pristine purity, nor to any state approacii- 

 ing it, by mere legislative fiat, and the sooner that fact is appreciated and 

 constructive measures are taken tlie better for the public welfare. 



The pecuniary losses now suffered as the result of water pollutions are enor- 

 mous, and the preventable damage to the life and beauty of our streams, lakes, 

 and seacoast is beyond estimate in terms of mere money. If existing abuses 

 are to be corrected and new ones prevented without inflicting widespread 

 economic injury, something more constructive than drastic laws must come 

 into being. There must be corrective legislation, but it should be based on 

 something more substantial than a perfectly justifiable desire for improvement. 

 Complete utilization of raw materials is an ideal not attainable. Industry 

 must be accompanied by " waste," and the wastes must be dist»osed of in some 

 manner. The problem is to devise ways of disposing of them so as to mini- 

 mize their harmfulness while still permitting industrial development. Tliis 

 is the problem of the biologist, the chemist, and the engineer working in co- 

 operation. 



The effects of these pollutions on the fisheries are the only phases of the 

 subject that officially concern the bureau, and it has continued to endeavor, 

 so far as its means would permit, to contribute to the solution of the problems 

 involved : but it is futile to expect that much can be done unless money and, 

 particularly, trained and capable men are provided for the purpose of determin- 

 ing facts and their practical and scientific implications. 



PROPAGATION AND DISTRIBUTION OF FOOD FISHES. 



REVIEW. 



During the fiscal year 1923 the fish-ciiltiiral operations of the 

 bureau were conducted along the same lines as in 1922. Work at 

 some of the more remote substations had to be discontinued owing to 

 insufficient funds, particularly on the Pacific coast, where it is the 

 practice to operate widely scattered field stations on or near the 

 spawning grounds in order to supply the salmon hatcheries with 

 their full quota of eggs. No attempt was made to collect eggs of the 

 pike perch and yellow perch at the Bay City (Mich.) or the Swan- 

 ton (Vt.) substations. In the marine fish-cultural field the usual 

 offshore work of collecting and fertilizing eggs of the cod, haddock. 

 and other commercial species, and immediately returning them to the 

 natural spawning grounds, had to be omitted. 



The Green Lake (Me.) station was closed at the beginning of the 

 fiscal year by authority of Congress, on the recommendation of the 

 bureau. Fish-cultural work at this station has been handicaj^ped by 

 the nature of the water supply, taken from a large open pond, which 

 frequently during the early spring months attained a temperature 

 too high for trout rearing, thus necessitating the premature plant- 

 ing of all stock on hand. In view of the limitations imposed on the 

 work by these conditions, and the very appreciable increase in the 

 cost of maintaining and operating the station within recent years, it 

 was deemed advisable to close it. 



Generally speaking, conditions were not favorable to fish culture 

 during the year. Low- water stages on the west coast interfered with 

 the run of* fish in many of the streams early in the season, only 

 to be followed later by heavy floods, which in some instances carried 

 away the racks and permitted the escape of the brood stock held 



