4 U. S. BUREAU OF FISHERIES. 



and movements of the fish, and this can be gained only by the skill- 

 ful application of the methods of science. Nearly all persons con- 

 cerned in the great shrimp fisheries recently developed ofi" the South 

 Atlantic and Gulf Coasts view with concern the future maintenance 

 of the supply. Can the shrimp be wisely protected or most judi- 

 ciously exploited while we do not know when or where it breeds or 

 why it appears here or there in greater or lesser abundance ? Clearly 

 scientific studies have a very practical relation to the perpetuation of 

 such a fishery. 



Beyond a doubt, there is no one connected with the fishing industries 

 who believes, with reference to the majority of the existing fisheries, 

 that any of them will maintain its present importance in future time, 

 except as the resources upon which it is based may be conserved by 

 sensible measures of protection. And certainly no one concerned with 

 the determination of protective measures would hesitate to say that 

 we must know the fish (or shellfish) and its manner and conditions 

 of life if we would successfully protect it. 



It is, then, of direct and not indirect importance, of practical and 

 not theoretical significance to the fisheries that we should study the 

 fish and attempt to solve some of the many problems upon which 

 depend the perpetuation of the resources and the development of the 

 industries. The industries are founded absolutely upon the resources. 

 The maintenance of the resources is conditioned upon the results of 

 scientific inquiry. How shall depletion be prevented? To what ex- 

 tent can utilization be carried ? What are the possibilities of propa- 

 gation, the conditions, the results? What are the methods and con- 

 ditions of protection? How can the natural environment be im- 

 proved ? How can disease be combated or unfavorable conditions of 

 environment be changed ? It is such questions as these that scientific 

 inquiry must answer. The very statement of the purposes to be 

 served renders unnecessary the presentation of argument for their 

 pursuit. The merit of the service performed can best be determined 

 from the report of its progress that follows, allowing, as one must, 

 for the varied geographic and industrial interests to be served. 



The Bureau does not, of course, fulfill all of its functions in scien- 

 tific inquiry at any given time, but this report will serve to indicate 

 the present scope of work, as well as the progress that is being made. 

 It may be remarked finally that the activities of the fiscal year just 

 closed were reduced as compared with that of previous j'^ears, and 

 that further reduction will mark the year next to come, due to the 

 loss in course of the last year of not a few of the men who con- 

 tributed to the accomplishment of the year's work. What has been 

 done is due to the loyal and efficient services of men who have labored 

 without stint under conditions of discouragement. Acknowledg- 

 ment is due no less to those who have left only under the impulsion 

 of circumstances than to those who have found it possible to continue 

 in service. 



STUDIES OF FISHES. 

 ANATOMY OF THE SALMONS IN RELATION TO FISH CULTURE. 



From time to time th& Bureau has had reports of abnormal condi- 

 tions of brood fish at its trout stations, such as the sterility of brood 

 fish which have been used for several years. These conditions do not 



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