Opportunities and Constraints in Marine Shrimp Farming
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SRAC Publication No. 2600 VI July 2002 PR Opportunities and Constraints in Marine Shrimp Farming Jack M. Whetstone1, Gravil D. Treece2, Craig L. Browdy3 and Alvin D. Stokes4 Shrimp mariculture, the produc- The major aspects of shrimp mari- ly among species. Most tropical tion of saltwater shrimp in culture are sourcing or obtaining shrimp eggs are 0.00003937 inches impoundments and ponds, origi- brood for hatchery production, (220 micrometers) in diameter. nated in Southeast Asia where for maturation and reproduction of They hatch within 14 hours at centuries farmers raised incidental broodstock, genetic selection, egg 28 oC (82.4 oF). The nauplius is the crops of wild shrimp in tidal fish and nauplii production, larval first larval stage and it is attracted ponds. The shrimp were not con- rearing, postlarval holding and to light. In natural settings, the sidered of great value. Time has sales, growout in ponds and race- shrimp postlarvae (PL) are carried changed this perspective, and ways, production of bait or edible by ocean currents to the protection shrimp culture has grown into one shrimp, harvesting, processing, of estuaries, where they have a of the largest and most important and sales to a world market. diet rich in various sources of aquaculture crops worldwide. All nutrition. They remain there until kinds of shrimp (coldwater and Life cycle the late juvenile or early adult warmwater) are highly desirable stage. now in a world market. Most Juveniles and adults migrate off- The growout phase in bays and coastal countries have a harvest shore, and in the stable environ- ponds generally takes 4 to 5 industry for shrimp, and about 100 ment of the ocean they mature, months (16 to 20 weeks), depend- of those catch enough to export. mate, and spawn eggs in offshore ing on the environmental condi- More than 50 countries practice waters (Fig. 1). All but one species tions, species, and, in bays, the shrimp aquaculture. Shrimp cul- within the Family Penaeidae fol- timing of migration to offshore ture increased 300 percent from low this life cycle sequence, areas. 1975 to 1985, and 250 percent from although the sequences vary great- 1985 to 1995. If it increases 200 per- cent between 1995 and 2005, world shrimp culture production will be at 2.1 million metric tons (MT =1.1 Postlarvae Protozoea standard tons, 2,204.6 pounds or 1,000 kg). According to a report of Mysis the Food and Agriculture Nauplius Organization of the United Marsh Nations, world production of Juvenile farmed shrimp reached 1,130,000 Bay MT of whole shrimp in 1999. (estuary) Postlarvae Adult 1 Clemson University Eggs 2Texas A & M University 3Marine Resources Research Institute, South Carolina Department of Natural Resources OPEN OCEAN 4Waddell Mariculture Research and Development Center, South Carolina Department of Natural Resoruces Figure 1. Penaeid shrimp life cycle. History of marine shrimp through the U.S. Department of females with ripe, egg-laden farming Agriculture and the U.S. ovaries (gravid females) are Department of Commerce/ brought from the sea for spawning In 1933 M. Fujinaga of Japan initi- NOAA/Sea Grant Program. in captivity. The availability and ated research on Marsupenaeus cost of wild gravid females can The first attempts at commercial japonicus (previously known as fluctuate. Their use precludes shrimp farming in the U.S. Penaeus japonicus) and opened the genetic selection and complicates occurred in the late 1960s and door to modern shrimp farming. efforts to control disease introduc- early 1970s, following the His work contributed largely to tion. Thus, to achieve better con- Ecuadorian industry’s lead based the initial development of the trol, technologies for captive matu- upon the culture of Litopenaeus industry. In the 1930s, J.C. Pearson ration and reproduction have been vannamei and Litopenaeus described the eggs of some west- developed. This has allowed for stylirostris. The initial U.S. industry ern hemisphere penaeid shrimp the establishment of breeding pro- used native species of white, and the life histories of some grams for fast growing, specific brown and pink shrimp. U.S. American penaeids. This was an pathogen-free and/or resistant researchers found that non-native important step in understanding stocks. Captive maturation is shrimp from the Pacific coast of how to obtain desired results in achieved by placing broodstock in Central and South America were hatchery and growout procedures. large (13-foot, 4-m) diameter tanks easier to culture and more produc- Since adults migrate offshore to at densities of five to seven shrimp tive in ponds. Gradually, commer- the more stable salinities and tem- per 10.7 square feet (1 m2). The cial producers in the U.S. concen- peratures of the ocean, where they most important parameters for trated on non-native species such mature and reproduce, commercial successful maturation of penaeid as L. vannamei, now the most pop- hatcheries found that they had to shrimp are constant temperature, ular species cultured in the mimic natural conditions. salinity, pH, light, and good nutri- Western Hemisphere. Hatcheries worked better with tion (Table 1). higher salinities and cleaner water, Significant early contributions Once the gravid female is ready to whereas growout worked best in from private industry in the U.S. spawn, it releases eggs into the the back bays and estuaries with came from Ralston Purina and water, fertilizing the eggs by lower salinities. Marifarms in Florida, and Dow simultaneous rupturing of the Chemical in Texas. Texas now pro- In the 1940s and 1950s, Robert spermatophore. The eggs exit the duces more farm-raised shrimp Lunz at the Bears Bluff Laboratory ovipositors, located at the base of than any other state—approxi- in South Carolina continued the the third pair of walking legs, and mately 8 million pounds (3.63 mil- development of extensive shrimp sink. In non-grooved white shrimp lion kg) of heads-on shrimp in production. He flooded tidal the eggs brush back against the 2001. Florida has the largest hatch- impoundments when native spermatophore as the female is ery in the U.S. It can produce 180 shrimp populations were migrat- continuously swimming. If the million PL per month, but sends ing, controlled predators, and used female stops swimming, or her most of them to Honduras for water exchange to maintain dis- swimming is interrupted, the eggs growout. solved oxygen levels. His work may fall straight down and are not refined extensive shrimp farming. Once shrimp hatcheries began sup- likely to be fertilized. plying large quantities of shrimp Harry Cook and others at the Most cultured adult shrimp pro- to farmers, the production of farm- National Marine Fisheries Service duce 150,000 to 200,000 eggs per raised shrimp expanded rapidly. laboratory in Galveston, Texas spawn, depending upon the size of Problems with disease and poor established the “Galveston the female. The larger species, such water quality in the early 1990s Technique” of culturing shrimp as Penaeus monodon, can produce slowed worldwide production for larvae, which helped to expand 700,000 to more than 1 million a few years. In recent years, pro- shrimp hatchery technology. eggs each spawn. After hatching, duction has been increasing Research on the culture of larval shrimp develop through several because of new disease control shrimp started there in 1959 as larval stages. The eggs hatch into protocols and water recirculation part of an investigation into the the first larval stage, called the and reuse technologies. life history of native shrimp in the nauplius. The microscopic nau- Gulf of Mexico. Harry Cook pub- plius larvae are planktonic and lished a generic key to the zoeal, Shrimp hatcheries feed on their yolk sacs for 48 mysis, and postlarval (PL) stages The hatchery cycle begins with hours. The nauplius stage is the of littoral Penaeidae of the north- broodstock. In many hatcheries, best larval stage to ship or trans- west Gulf of Mexico in 1965. Other groups also worked on larval rear- ing of penaeids in the U.S., mainly Table 1. Parameters for tropical shrimp maturation and allowable in Texas. The Texas Parks and ranges per 24 hours. Wildlife Department and some of the universities published works Salinity Temperature pH Light D.O. on the subject very early. A signifi- 27-36 ppt +/- 0.5 27-29 oC +/- 2 o 7.8 +/- 0.2 14 L, 10 D 5 ppm + cant aquaculture research and o development effort continues (80.5-84.2 F) port. Starting at about hour 36 after hatch, microscopic, single-celled algae and later other minute forms of zooplanktonic microcrustaceans (usually freshly hatched brine shrimp, Artemia nauplii) are fed to specific larval stages. The larvae develop through three zoea stages and three mysis stages before metamorphosing into a form more closely resembling a typical shrimp or postlarva. Development through larval stages takes 9 to 11 days from hatching (at 28 oC or 82.4 oF). Some hatcheries shorten the larval time in the hatchery by raising the temperature; however, care must be taken because bacterial prob- lems develop faster at the higher temperatures. The most successful Figure 2. Larval rearing facility. hatcheries control bacteria and At the high stocking densities typi- other diseases through disinfection sive according to stocking density cal of intensive culture systems, and other preventive measures. and associated management para- meters. Large ponds or impound- natural food organisms do not One of the most important aspects ments may be stocked at low den- supply enough nutrition and the of the location and functionality of sities, producing crops with little farmer must provide a nutritional- the shrimp hatchery is water quali- or no supplemental feed and rely- ly complete ration. Feeding effi- ty. Almost all hatcheries require ing on wind or water exchange to ciency is crucial, as high quality oceanic quality water on a 24-hour manage pond water quality.