METHODS

GENERAL APPROACH

Three cooperating producers distributed among two Arkansas County were selected for the program resulting in a total of five verification ponds. Two cooperators and three verification ponds are located in Ashley County. The third cooperator with two verification ponds is located in Woodruff County. Cooperating producers agreed to manage the verification ponds according to the recommended management practices for a period of 2 years. The program coordinator visits each farm weekly during the production season to collect production and water quality data and to make recommendations for action the following week. The program coordinator also verify all stocking and harvesting procedures. The initial and remaining fish inventory at the end of the 2-year production study is verified in order to calculate survival, feed conversion ratio, and yield. Feed, aeration and other production expense data will be collected and utilized to estimate operating costs, net returns, and breakeven prices.

INVENTORY

Ponds selected for the program were growout ponds that were in production with fish stocked the previous year. Empty ponds were not accepted for the program. Starting with a clean dry pond would have made the harvest of market-size fish in the first year of the program very unlikely. Consequently, starting with a clean dry pond would necessitate the addition of a third year to the program, which was not recommended in the 1997-2000 Catfish Yield Verification Report.

Ponds selected for the program needed to have been in production the previous year. However, the inventory of market-size fish be minimized to the extent possible prior to starting the verification process. Therefore, selected ponds had been seined and market-size fish harvested within a few months preceding the beginning of the program. The "beginning inventory" was verified prior to stocking the ponds and the "final inventory" will be verified at the end of the two-year verification process.

To assess the fish inventory, ponds were seined twice with a small mesh fingerling seine. All harvested fish were weighed back to the pond with a hydraulic boom. During the loading process, two loading nets of about 300-400 lb each were kept aside to generate a sample of about 800 fish per pond. Those fish kept aside were individually weighed with a bench scale to estimate the size distribution of the fish population. The beginning inventory was estimated by assuming a harvest efficiency (proportion of the total fish population actually harvested) of 88% (Appendix 1).

STOCKING

All fingerlings stocked in the verification ponds were obtained from the cooperator’s farm. Fingerlings ponds were seined and fish were kept in a live-car. A random fish sample of approximately one hundred fish were measured to the nearest half-inch to asses the size distribution of the fingerling population to be stocked in the verification pond. If fingerling smaller than five inches were present in the sample, fingerlings were graded with the floating UAPB-grader. Only fingerlings larger than 5 inches were stocked in the verification ponds. The average fingerling size (lb/1,000) at stocking was estimated by group-weighing and counting at least 4 baskets of fingerlings.

HARVESTING

Harvesting should commence when our records indicate that approximately 1,000-2,000 lb/ac of fish have reached an average weight of 1.5 lb, with a minimum of 10,000 lb ready for market. A month before the expected harvest date, fish should be checked for off flavor. If fish are off flavor, ponds may be treated with algicides if necessary. When our records indicate that approximately over 2,000 lb/ac of fish have reached 1.5 lb, every reasonable effort should be made to get these fish on a processor's schedule. If, after a period of three weeks, the fish cannot be scheduled for any reason, the cooperator must agree to harvest the fish and move them to another pond. This procedure will be repeated as often as necessary. All harvested fish will be graded with the UAPB in-pond floating grader prior to loading to separate food-size fish from sub-marketable fish. A pre-grade sample of about 400 fish will be collected from the sock before grading begins. During grading, the food-size fish will slide across the grader and will be collected in a 1.75 or 2.00 inch square mesh sock. The sub-marketable size fish will swim down through the bars back to the pond. The food-size fish will be weighed as they are loaded into the hauling truck with a hydraulic boom. During the loading process, two small loading nets of about 300-400 lb each will be emptied into two hoop-nets to generate a sample of at least 400 food-size fish. Once all the loading is completed, all the sampled fish will be individually weighed with a bench scale to estimate the size distribution of the fish population and then returned to the pond.

WATER QUALITY MONITORING

A Cooperative Extension Agent will take weekly water samples from the ponds to be analyzed for parameters that may affect fish health and pond performance. These parameters include temperature, pH, TAN, Nitrite, and Unionized ammonia. Chloride readings will be taken whenever nitrite readings are above 1 ppm or total ammonia readings are above 5 ppm. Alkalinity, hardness, and chloride readings will be taken every 6 months or as necessary for pond treatments. A minimum of 60 ppm chlorides will be maintained throughout the trial period.

FISH HEALTH MONITORING

The cooperating farmers will immediately report and transport suspect fish to the diagnostic laboratory and follow the recommendations of the fish health specialist. However, periodic fish health checks may be performed by CES personnel during certain disease seasons, if fish go off feed or hang around the aerator, or whenever fish health may have been compromised.

RECORD KEEPING

The cooperator must agree to maintain adequate records on the verification ponds on a daily basis. These records should include:

• Stocking Records

• Harvest Records

• Daily Feeding

• Mortality Estimates

• Oxygen High/Low

• Hours of Aeration

• Flavor Checks

• Weekly Water Quality

• Medications or Treatments

• Pond Specific Operating Expenses

• Water Pumping Information