ARS | Publication request: Temperate Climate Double Crop Production Strategies of Litopenaeus Vannamei in South Carolina

Submitted to: Aquaculture America Conference
Publication Type: Abstract
Publication Acceptance Date: October 1, 2002
Publication Date: February 1, 2003
Citation: Stokes, A.D., Browdy, C.L., Weirich, C.R., Sandifer, P.A. 2003. Temperate climate double crop production strategies of Litopenaeus vannamei in South Carolina [abstract]. In: Aquaculture America Conference. p. 278.

Technical Abstract: Each year, shrimp growers deal with a number of issues associated with producing shrimp in temperate climates: limited production season, shortage of hatchery produced postlarvae during optimum stocking dates, possibility of disease outbreaks or losses due to late season storms such as hurricanes, and lower end-of-the-season prices for their crop. In an attempt to minimize many of these production risks and improve marketing opportunities, biologists at the Waddell Mariculture Center (WMC) developed a double crop production strategy using nursery reared juveniles to maximize production of two crops of shrimp in a limited 5-month production season. This management strategy relies upon the quality production performance of the US Marine Shrimp Farming Program selected stocks, which can be achieved in earthen ponds. The strategy was designed to provide two crops of reasonably sized shrimp during a 150 day growing season. The first crop would be harvested before hurricane season and provide a mid-season cash flow when prices are generally higher. By using a nursery and spreading stocking to two times per season, problems with commercial seed availability could be minimized and at intensive stocking densities of 400,000 and 600,000 shrimp/ha, water quality deterioration is much less likely to occur in zero water exchange ponds that are managed for 80 days or less. Both crops of shrimp of the double crop production strategy were head started by stocking ten-day-old postlarvae into a zero water exchange nursery at a rate of 2,000/m. The postlarvae were reared for 32days before being stocked at a mean size of .55g and .31g respectively. The shrimp were stocked into six .10-hectare ponds. Two treatments composed of three ponds each were stocked at 400,000 and 600,000 juvenile shrimp/ha. The first crop was stocked in April and harvested in July, 80 days after stocking. The ponds were dried for 24 hours, refilled and stocked with nursery reared juvenile shrimp three days later at the same densities of 400,000 and 600,000 juvenile shrimp/ha. The second crop was harvested in September after 64 days of growout. The shrimp were fed a 35% protein (with 2.5% squid) commercial shrimp diet according to a WMC feed management regime. Paddlewheel aeration was used to improve water quality in the zero exchange ponds. Aeration was employed at a rate of 30 hp and 40 hp/ha for stocking rates of 400,000 and 600,000 shrimp/ha. During growout, no unusual mortality was observed. Production results and costs will be analyzed and compared to determine risk and production benefits for both intensive double crop production strategies in South Carolina.