cultivating them were developed. Now, commercial alligator farms 

 are supplying the market with meat and hides. As many as 13 

 alligator farms are producing about 1,000 animals per year. 



Some progress has been made in bullfrog culture and a few 

 small-scale frog farms do exist in the southeastern States. 

 However, several cultural problems remain to be solved to make frog 

 rearing a reliable and lucrative endeavor. 



Rotation with Arable Crops 



Several combinations of rotating arable crops with aquatic crops 

 are now being practiced. As previously mentioned, crawfish in 

 Louisiana are reared in rotation with rice crops. Rice is sown, 

 grown, and harvested. Following harvest, the land is reflooded and 

 seeded with crawfish. The crawfish feed on the rice straw and 

 wastes and are harvested the following winter or early spring. 



Catfish are sometimes combined with rice or soybeans on a rotation 

 program. Nitrogenous waste products produced during catfish 

 production serve as a source of fertilizer. Rotation can reduce 

 the need for fertilizers, resulting in increased profits. 



Use of Geothermal Springs, Waste Heat, and Waste Water 



Geothermal (hot) springs have been used for fish farming for 

 several years. A number of companies are experimenting with using 

 warm cooling water from pulp and paper mills, steam plants, and 

 atomic generating plants for aquaculture. The heated effluent can 

 be used directly or mixed with cooler water sources to obtain 

 optimum growth temperatures. Catfish, trout, salmon, carp, 

 shellfish, tilapia, and other species have been successfully reared 

 using water from these sources. • ;.: i. 



One of the largest salmon hatcheries in the world (a private 

 hatchery located in Oregon) , uses cooling water from a pulp and 

 paper mill to double the growth rate of young salmon for release in 

 a commercial ocean ranching program. 



Using fish, shellfish, or aquatic plants to help remove organic or 

 inorganic pollutants from wastewater and then harvesting the 

 resulting crop is also practical in some areas. Effluent ponds of 

 wastewater from municipal, industrial, agricultural, and even 

 aquacultural sources can be high in nitrogen and phosphorous, two 

 of the primary elements in the plankton food chain. This type of 

 water develops excellent plankton blooms for filter feeding fish. 

 In some areas, walleye, northern pike, or muskellunge fry have been 

 stocked in effluent ponds for growth to a stockable size. Bait 

 minnows also show good promise for this type of culture. 



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