16 



SUMMARY 



1. Channel catfish were stocked and fed at densities of 3,000 and 

 500 fish per acre (7,413 and 1,483 fish per hectare) in the 

 similar halves of a pond divided by a coarse-:.ieshed screen 

 which permitted free circulation of water. Minimal differences 

 in growth in the two populations suggests that it may be 

 practical to confine and feed a dense population of catfish 



in a fenced-off, manageable portion of a larger and less 

 manageable body of water. 



2. We measured the success of stocking 1-inch (2.5-centimeter) 

 channel catfish in 1-acre (0.4-hectare) ponds at densities 

 ranging from 2,365 to 7,138 per acre (5,844 to 17,638 per 

 hectare) , and considered the value of providing supplementary 

 feed to fish in such small sizes and light densities. Over 



a 75-day period rates of survival in individual ponds ranged 

 from 14.5 to 79.1 percent. Feeding increased survival by 

 about 22 percent, and pounds of final standing crop by 

 76 percent. 



3. We fed 1,500 channel catfish in each of four 1-acre (0.4-hectare) 

 ponds and 1,500 catfish confined in two cages (175 fish per 

 cubic yard, or 230 per cubic meter) in each of four other 1-acre 

 (0.4-hectare) ponds, in order to compare the efficiency of the 

 methods. The fish were fed five days each week over growing 

 periods ranging from 150 to 160 days in individual populations. 

 Rates of survival averaged 97.3 in the uncaged, and only 70.1 

 percent in the caged populations. Fish free in the ponds 

 averaged approximately 25 percent longer and 119 percent heavier 

 than those confined in cages. Final standing crops of uncaged 

 populations were more than 2.5 times as heavy as those popula- 

 tions confined to cages. Production failures of catfish in 

 cages were attributed primarily to dietary deficiencies through 

 use of a feed designed to supplement the natural food in oonds. 



4. In 1969 we conducted a test to determine if channel catfish 

 could be successfully reared in cages floated in a congested area 

 of a public fishing lake. The cage was suspended in a boat slip 

 in the center of a complex of docks where both pedestjri'^n and 

 boat traffic passed within a few feet (meters) of the cage. 

 Gains by the fish caged in the congested area were sufficiently 

 greater than those made by fish caged in two small, undisturbed 

 ponds as to establish that growth was not inhibited or limited 



