Shrimp farming

Holmstrom K, Graslund S, Wahlstrom A, Poungshompoo S, Bengtsson BE, Kautsky N (2003) Antibiotic use in shrimp farming and implications for environmental impacts and human health. Int J Food Sci Technol 38 255-266... 

Overfishing has seen an escalation to the point that many fisheries have been closed because of lack of profit (ludicello 1999). On the other hand, marine ferming causes eutrophication and pollution ofthe waters. In many tropical areas, shrimp farming is also deleterious to the mangrove forest, which has been destroyed to make space for the farms. The size of the problem is made clear by a ban in India and Honduras to shrimp farming along the coasts. 

Silva CAR, Rainbow PS, Smith BD. 2003. Biomonitoring of trace metal contamination in mangrove-lined Brazilian coastal systems using the oyster Crassostrea rhizophorae comparative study of regions affected by oil, salt pond and shrimp farming activities. 

As already mentioned above, research into the needs of various animal groups for healthy, fast, and controlled development has led to the definition of preferred feed components and the development of complex rations, which do not only provide food but also guarantee animal health and growth. This is particularly true for feeds for specific animal farming technologies, such as the already traditional feed lot formulations for cattle or the more recently formulated nutrients for fish and shrimp farming, and for pet foods. 

FIGURE 37.3 A farmer checks the consumption of pellet feed by shrimp (Penaeus monodon) from a feed tray at a shrimp farm in Hat Yai, Thailand. A Secchi visibility depth of approximately 30-50 cm is generally maintained by the addition of fertilizers and pellet feeds. Ponds are stirred by electrical or diesel powered paddle wheels in order to keep dissolve oxygen levels above ca. 3 mg/L. Planktonic and benthic cyanobacterial blooms are a constant threat to pond management and productivity in shrimp farming. 

FIGURE 37.5 Microscopic view of a benthic bloom from a marine shrimp farm near Hiroshima, Seto Inland Sea, Japan. Benthic blooms are commonly called lablab and this bloom consists of cyanobacteria (Oscillato-ria spp. and Spirullina spp.) and diatoms (400x magnification). 

First, on sunny days benthic cyanobacterial mats rise to the surface and are blown to the edge of the ponds where they decompose. This generally causes an increase in the levels of ammonia, a decrease in the dissolved oxygen, and outbreaks of disease. Hence cyanobacterial blooms can cause husbandry problems and fish kills. Cyanobacteria are also associated with reduced productivity in penaeid shrimp farms (Yusoff et al., 2001). 

While hsh kills have occurred during cyanobacterial blooms, the direct link between mortalities in hshponds and cyanotoxins has been elusive, because fish kills can often be explained by low levels of dissolved oxygen or increases in ammonia concentration when the bloom crashes (Seymour, 1980 Sevrin-Reyssac and Pletikosic, 1990). For example, recently in a Japanese shrimp farm, a bloom of Chroococcus turgidus was associated with mass mortalities of farm-raised Penaeus japonicus, but the direct cause was the increase in pH of pond water (Momoyama, 2004). 

FIGURE 37.9 Microscopic view of Nodularia spumigena which occurs on occasions as a toxic planktonic bloom during summer months in earthen ponds at shrimp farms (Penaeus monodon) on Palmers Island, northern New South Wales, Australia (trichome width of 12 J,m, 400x magnification). 

In recognition of enviromnental problems by effluent from fish farms, freshwater mussel, Elliptio complanata, has been used to treat pond water by removing cyanobacterial blooms of Microcystis from aquaculture systems (Stuart et al., 2001). Similar studies have been carried out to treat effluent from shrimp farms and other aquaculture operations. 

Fig. 10.1 World shrimp farming production by species using FAO 2011 statistics.

SPF Penaeus vannamei in Asia resulted in dramatic increases (a tripling) in total shrimp farming production between 2000 and 2009 (Fig. 10.1). 

Using hatchery-produced seed was expected to increase the reliabihty of shrimp farming, and shrimp hatcheries were developed in both hemispheres. PL were produced in land-based hatcheries from wild-caught broodstock. These PL were genetically wild animals because their parents... 

Biosecurity measures in specific pathogen free shrimp hatcheries 331 Table 10.1 Shrimp farming eras based on FAO data of global production... 

The other obstacle to industry growth in this era was the continued use of wild animals. Shrimp farming production during the hatchery era reached a carrying capacity for use of wild, non-domesticated, non-SPF animals. While farmers tried increasing stocking densities to increase yields and profits, their use of diseased, wild animals precluded these attempts and prevented industry growth. 

Based on the excellent results of pond trials in 1991, aU US shrimp ponds were stocked with High Health PL in 1992. Total production of the US industry doubled as a direct result of this innovation. Use of High Health shrimp in commercial farms increased production and survival, improved feed conversion ratio (FCR) and narrowed harvest size distribution all of which contributed to increased profitability. In addition to increased production, use of High Health shrimp reduced incidence of shrimp disease. It was predicted that the shrimp farming problems that were solved by use of SPF shrimp in the US industry could be duplicated elsewhere (Wyban et al., 1992). 

It is often said that the three most important factors in real estate valuation are location, location and location. This is also true for an SPF hatchery. The first step in an SPF hatchery biosecurity plan is site selection. A shrimp hatchery requires abundant supplies of high quality sea water. High quality sea water is not polluted with industrial or urban pollutants and is far from other shrimp farming activities. In some countries where a successful hatchery develops others soon follow, and this is a negative factor in SPF hatchery site selection. An extreme example of this can be found in Wenchang, China, a small coastal town on Hainan Island. More than 600 shrimp hatcheries operate in a coastal area less than 50 km in length. It is very difficult for a hatchery operator to maintain good biosecurity in such a location. 

Incoming sea water is the most likely vector for introducing a pathogen to an SPF hatchery. If the hatchery is located in a shrimp-farming region (most... 

Vehicles coming from a shrimp farm to the hatchery (either owned by the hatchery or by the shrimp farm) to pick up PL are a significant risk of pathogen introduction. Trucks may carry viral particles in mud stuck on the wheels or body of the truck. When driving on shrimp farms, trucks often crush shrimp that have been dropped on the farm roads and may carry the shrimp carcass. 

Table 10.3 Estimated P. vannamei broodstock and PL requirements for world shrimp farming in 2011...

Estimates of P. vannamei broodstock and PL requirements for world shrimp farming are fisted in Table 10.3. Approximately 500000 pairs of SPF P. vannamei broodstock are required to produce the 2.5 m MT of shrimp grown annually. 

Over the last decade, shrimp farming annual crop value has tripled as a result of the widespread use of domesticated P. vannamei. In 1997, global farmed-shrimp annual production of 700000 MT had a total crop value of about 3.5 billion based on an average price of 5/kg (FAO Fisheries and Aquaculture Department, 2010). Widespread adoption of P vannamei over the last 10 years resulted in sustained production increases of 23 %/year (Wyban et al., 2005). While shrimp prices declined as a result of increasing supply, total shrimp crop value today is worth more than 11 billion based on production of 3.1 m MT and a worldwide price of 3.50/kg. This tripling of industry crop value over 15 years directly resulted from domestication, breeding and widespread adoption of P. vannamei. 

CARPENTER N and BROCK J (1992) Growth and survival of virus-infected and SPF P. vannamei on a shrimp farm in Hawaii, in Fulks W and Main K (eds). Disease of Cultured Penaeid Shrimp in Asia and the United States. Honolulu, HI The Oceanic Institute, 285-293. 

WYBAN J (2009) World shrimp farming revolution Industry impact of domestication, breeding and widespread use of SPF P. vanruimei, in Browdy C L and Jory D E (eds). The Rising Tide, Proceedings of a Special Session on Sustainable Shrimp Farming. Baton Rouge, LA World Aquaculture Society, 12-21. 

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