Artificial fertilization is by no means a simple process. Considera- 

 tion must be given to the conditions and variables of the environment which 

 affect both procedure and results of fertilization. Such environmental com- 

 plexities are presented in this report by assembling information which occurs 

 in fish cultural and limnological literature. The objective is to show how 

 and where sirtificial enrichment applies to the present culture^, management, 

 and investigation of fresh-water fisheries in this country. No effort has 

 been made to advise or outline a method of fertilizing^ the intent is to 

 minimize meaningless trial-and-error experiments by giving the investigator 

 a grasp of the complex nature of the subject. The literature reviewed is 

 essentially North Aiaerican_, but certain Asiatic and European reports are 

 included. These European reports represent a composite of vast European 

 knowledge, and frequent references will be made to them. 



Early appearance of pond-culture fertilization in scientific literature 

 dates back to European work in the late nineteenth century. Da^/is and Weibe 

 (1930) and Smith (193Ua) reviewed the publications of their predecessors in 

 this field, and Neess (19li9) presented a historical synopsis of European 

 pond culture. These summaries indicated that the first European experiments 

 were directed toward the production of plankton and were later applied 

 directly to carp culture, American work began in a similar fashion (Embody, 

 1921j VJiebe, et alo, 1929j Wiebe, 1930), As a scientific proced^jrej early 

 enrichment experiments had one fault in common; they proceeded from the nu- 

 trient addition to fish or fish-food production disregarding fundamental 

 physical, chemical, and biological factors which, directly or indirectly^ 

 influence enrichment and the resultant changes in productivity. Cognizant of 

 this, some more-recent investigators have conducted experiments of greater 

 significance. Nevertheless, there exists an incomplete understanding of 

 fertilization dynamics which can be supplemented only by careful experi- 

 mentation. 



FUND.1MENTALS OF AQUATIC FERTILIZATION 



Numerous factors, inherent in the metabolism of fresh water, concern 

 the process and outcome of artificial fertilization. They may be classi- 

 fied as physical, biological and chemical, but this grouping is made only 

 to facilitate discussion. In practice it is necessary to consider such 

 things as they actually exist - highly interrelated. Moreover, few fac- 

 tors remain constant within a given body of water. The variability ar.d 

 interaction of these factors present basic problems in the understanding 

 and success of aquatic fertilization. 



Physical Considerations 



Reference to physical factors in literature is abundant but fragmen- 



