A lower per centage of operations with 1 to 19 surface acres raised channel multiplied by blue hybrids (11.9 per cent) compared with larger operations; at least 20.0 per cent of operations in the three larger size categories raised channel multiplied by blue hybrids.
Operations in the West region were larger in terms of both average number of growout ponds (27.9) and average total surface acres (314.9 acres) than operations in the East region, which averaged 9.6 ponds and 95.1 total surface acres. Average pond size was 10.8 surface acres.
Well water was used for 99.8 per cent of all growout ponds in the West region, while the majority of ponds (66.7 per cent) in the East region were filled using surface water. In both regions, the majority of ponds averaged four to five feet in depth. A higher per centage of operations in the East region than in the West region had ponds with average water depths greater than five feet (28.3 and 13.2 per cent of operations, respectively).
Dissolved oxygen levels were hand monitored on about one-half of operations (48.9 per cent). Automated sensors were used by 40.9 per cent of operations. Almost one-half of operations with one to 19 surface acres did not regularly monitor dissolved oxygen (46.7 per cent). For all operations, slightly more than one-third (35.2 per cent) tested water quality at least once a month. A lower per centage of operations with one to 19 surface acres (12.5 per cent) tested water quality at least once a month than did operations with 20 or more acres. More than one-half of operations with one to 19 surface acres (50.7 per cent) did not test water quality in 2009.
The most important criterion for selecting fingerlings or stockers for stocking was price (33.9 per cent of operations), followed by producer’s reputation (28.8 per cent of operations), and growth characteristics (15.0 per cent of operations). Distance from supplier was rarely the most important criterion (1.5 per cent of operations). The operation average stocking rate was 5,553 fingerlings per acre. The operation average stocking rates ranged from 4,224 fingerlings per acre on operations with one to 19 surface acres to 5,921 fingerlings per acre on operations with 50 to 149 surface acres.
Almost one-half of foodsize-fish operations (46.4 per cent) stocked at least one fish species in addition to the primary fish (catfish). The highest per centages of operations stocked threadfin shad (29.6 per cent of operations), a natural food item and phytoplankton grazer, and grass carp (25.4 per cent), an herbivore used primarily to control aquatic weeds. Multibatch-harvested fish represented the highest per centage of channel and channel x blue hybrid catfish harvested (82.4 per cent). Single-batch harvested fish represented a much smaller per centage (13.8 per cent) of the harvest, although 41.2 per cent of channel times by blue hybrid catfish were harvested by single-batch practices.
More than one-half of operations (53.9 per cent) lost foodsize fish to predation, while 28.1 per cent of operations lost fish to low dissolved oxygen. The three diseases causing fish loss on the highest per centages of operations were columnaris (39.0 per cent of operations), enteric septicemia of catfish (36.6 per cent), and winter kill (20.6 per cent). Severe losses (average loss per event of more than 2,000 pounds) were caused by predation and columnaris, respectively, in 5.2 and 3.5 per cent of growout ponds. Only 6.2 per cent of foodsize-fish operations stocked any fish that had been vaccinated for ESC. Of fish stocked into growout ponds in 2009 on all foodsize-fish operations, an operation average of 4.9 per cent were vaccinated against ESC.
The columnaris vaccine became available to the catfish industry in March 2005. In 2009, 3.9 per cent of operations stocked any fish that had been vaccinated against columnaris disease into growout ponds. An operation average of 2.7 per cent of fish stocked into growout ponds in 2009 were vaccinated against columnaris. During 2009, off-flavor problems delayed harvest on 80.7 per cent of all operations and 48.1 per cent of all ponds on operations from which foodsize fish were harvested. The per centage of operations with delays due to off-flavor increased as operation size increased.
Highlights Of The US Catfish 2010 Report
The majority of foodsize-fish operations (81.9 per cent) raised unspecified lines of channel catfish. More than one-fifth of operations (21.2 per cent) raised channel multiplied by blue hybrid catfish.