WWW.WAS.ORG • WORLD AQUACULTURE • MARCH 2016 29 or bleach to prevent accumulation of harmful bacteria and miscellaneous fish and shrimp. Next, shrimp farming enters the core phase, that is, the application artificial fertilizer. A folk song widely sung by Chinese shrimp farmers mentions “the golden part of shrimp farming is to fertilize water because fertilized water can feed the healthy prawns.” Traditionally farmers make use of organic fertilizers such as chicken manure and urea. Chicken manure always brings numerous bacteria into aquaculture water. With urea, one major disadvantage is the very short reaction time; consequently, algae will grow and bloom during this short period. Massive algae dieoff and water quality problems are associated with the excessive use of urea. The current application of artificial fertilizer by farmers is different from the traditional mode of shrimp farming. Fertilizers supply inorganic nutrients to support beneficial algae and other natural foods for shrimp; simultaneously, farmers add probiotics that have a good reputation in the industry. After adjusting pond water quality, farmers start preparing ponds for stocking post-larvae. Despite the increase in temperature during late March, pond water temperature remains below the optimum level for shrimp growth. To accelerate juvenile growth, some farmers build greenhouses over ponds to raise the pond water temperature (Fig. 3). In Shanghai, well-funded farmers or aquaculture companies adopt greenhouse cultivation (Fig. 4) to effectively ensure good health of juveniles when they are transferred from the greenhouse to grow-out ponds, thus further aiding shrimp growth. Generally, shrimp farmers stock at high density, which requires much more energy to attain good shrimp growth, especially if the shrimp feed only on algae and zooplankton. Therefore, a compound feed supplement is necessary. Shrimp are fed various feeds during their life cycle, beginning with a shrimp cracker that functions as a starter feed for post-larvae, Chinese shrimp aquaculture has developed dramatically in recent years (FAO 2010). Many in the general public think that excessive feed and drug abuse in shrimp aquaculture is one of the major causes of water pollution and eutrophication (Diana 2009, Paul and Vogl 2011). Pollution of the surrounding environment is one of the main reasons for the public’s negative impression of traditional shrimp farming (Rivera-Ferre 2009). It is difficult to address this issue because of the lack of data collected in the field. Therefore, investigation is urgently needed to understand the influence of shrimp aquaculture on the environment. The international metropolis of Shanghai is regarded as the “Paris of the Orient” and is the center of China’s economy and finance. In addition, the city’s agriculture has developed steadily. With its economic advantage, agriculture in Shanghai has gradually become impeccable. In January 2015, the Chinese Ministry of Agriculture formally identified Shanghai as a national modern agriculture demonstration area. Aquaculture is a vital part of agriculture. The development of aquaculture is a part of urban planning and contributes to ecological management of the environment. The Shrimp Farming System Pacific whiteleg shrimp Litopenaeus vannamei and giant river prawn Macrobrachium rosenbergii are important culture species in Shanghai’s shrimp aquaculture. In Pudong New District, Jinshan District and Fengxian District of Shanghai, various small (Fig. 1) or large (Fig. 2) shrimp farms, have been created to solve the problem of local employment and yield considerable economic value. In China, shrimp culture generally begins at the end of the calendar year. During this period, farmers make simple repairs to culture ponds. For example, they remove accumulated sediment, taking advantage of the sun and cold in winter to clean the pond completely. During March, two weeks before shrimp larvae are stocked into ponds, farmers add large amounts of quicklime Shrimp Farming in Shanghai, China Menghong Hu, Yanming Sui, Mingzhe Yuan FIGURE 1. A small-scale shrimp pond in Fengxian District, Situan Town. The farm has three ponds, each with an area of 10 mu (6667 m2). (Photo: Menghong Hu) FIGURE 2. A 3000-mu (200-ha) shrimp-culture pond during cleaning. (Photo by Menghong Hu). (CONTINUED ON PAGE 30)
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