FARM FISH PONDS 



A great deal of literature has been published in recent years on the 

 construction, maintenances and management of fferm fish ponds. Apparently 

 the public has been convinced of their practical, recreational, and con- 

 servational value. In response to such publicity, innumerable farm ponds 

 have appeared in various parts of the country. Fertilization is one of 

 the management practices commonly recommended and much pioneer work to 

 that end has been done in Alabama by H. S. Swingle and Ms collaborator, 

 E. V. Smith. Several of their reports are cited in the "List of References", 



A discussion of farm fish ponds as environmental entities related to 

 artificial enrichment is felt unnecessary because such treatment would mere- 

 ly overlap the preceding and subsequent sections of this report. Informa- 

 tion gleaned from farm-pond literature has already been presented and the 

 reader is referred to thosfe publications for more direct and pertinent data. 



One important issue, the practical value of fertilizing farm ponds, 

 is open to question. One might assume, after reading some of the litera- 

 ture, that fertilization is an essential phase of proper farm fish pond 

 management. However, fish rearing in farm ponds is not intensified as 

 in culture ponds, nor is it done for a marketable crop. Published reports 

 do not indicate the extent of harvest in farm ponds, but it is probable 

 that few of them are adequately cropped. Therefore, unless serious effort 

 is made to harvest the fish, it seems unwise to recommend the fertilization 

 of farm ponds where costs are involved. 



FERTILIZATION OF LAKES 



Thus far, specific discussion of aquatic environments has been mostly 

 limited to d^einable culture ponds. Delicate experiments in aquatic nutri- 

 tion have been conducted in laboratory containers where many natural varia- 

 bles can be eliminated or controlled. Much fertilization literature is de- 

 voted to farm fish ponds, and some to trials in lake enrichment. .These dif- 

 ferent types of lerlitic habitats can be arranged in a sequence of increasing 

 environmental conplexity, paralleled to a large extent by increasing size 

 and depth. The simplest is a laboratory receptacle, followed by outdoor 

 pools, drainable culture ponds, nondrainable culture ponds, farm fish ponds 

 and natural ponds, small shallow lakes, and, finally, larger lakes of in- 

 creasing physical and biological diversity. Notable changes occur in this 

 progression when it is considered from an enrichment point of view. The 

 first appears when the artificial retaining structure is replaced by natural 

 soil. A second important break exists between drainable and nondrainable 

 waters. A third of probable importance coincides with thermal stratifica- 

 tion. The second and third major changes in the nutritional succession 

 indicate basic differences between culture ponds and lakes so far as this 

 paper is concerned, and will be considered with other factors in the follow- 

 ing sections. 



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