82 DESCRIPTION OF IMPORTANT FISHERIES AND THEIR PRODUCTS 



ance of lake trout triggered a population explosion of small chub species, 

 the major forage-fish of the trout. This transition in fish stocks occurring 

 in recent years in the Great Lakes (Figure 6,1) has dramatically lessened 

 the abundance of the large, higher-valued species while many of the 

 small, lower-valued species have become excessively plentiful. The true 

 extent of these under-utilized fish available for exploitation is not known. 



1948 49 50 51 52 53 54 55 56 57 58 59 



Figure 6.1. Great Lakes fish production by groups of 

 species, in millions of pounds from 1948 through 1959^ 



but the potential output of the Lakes, which once was fairly stable at 

 an annual rate of 70 to 80 million pounds, now^ may run into hundreds 

 of millions of pounds^ This sudden change of the fish stocks has severe 

 impact on the commercial fisheries, which will be described briefly later 

 in this chapter. 



Changes in Other Fresh Water Fisheries 



Changes in other domestic, fresh-water fisheries in recent years have 

 been far less drastic than those in the Great Lakes. Several significantly 

 new fisheries, currently in the process of development, are worthy of 

 mention, however. 



The possibilities of fish-rearing in rice ponds of the southern L^nited 

 States were first sensed in the early 1950's from observations of the 

 growth of fish introduced inadvertently with the water supplies. Sub- 

 sequently, a number of rice farmers undertook seriously the roaring of 

 fish. Although this industry is still in its infancy (less than 25 thousand 

 acres are being farmed for fish — Figure 6.2), the rice ponds of Arkansas, 



