56 MARCH 2013 • WORLD AQUACULTURE • WWW.WAS.ORG We are witnessing the rise and apparent fall of the blue revolution with shrimp in the Kingdom of Saudi Arabia. Shrimp culture in Saudi Arabia started in 1983. Unlike Iran, where there is a directed development approach to benefit smallholders, in Saudi Arabia it has been purely a private sector initiative involving large companies. Presently Indian prawn (Fenneropenaeus indicus) farming is negotiating a crucial uncertainty in the Kingdom. Low stocking density and stricter biomass thresholds could not prevent viral diseases from wiping out shrimp crops. The storm cloud of cryptic infections in shrimp won the game. Three decades of global investigation into the immunity of penaeid shrimps provided no help to keep culture going. Can Indian prawn endure the viral battle? Most disease cases in the Kingdom have always followed a heavy downpour of winter rain – the ultimate environmental stressor. The historic flooding that occurred in Jeddah on 25 November 2009 (GES 2009), 30 December 20102 and 26 January 20112 were caused by catastrophic downpours. Disease outbreaks have always followed winter rains – March 2010, February 2011, November 2011 and the like in 2012. Heavy winter rain and uncontrollable surface runoff is a great microbial diluter and inducive leveller for organic leacheates and their putrescent derivatives. Low temperatures weaken shrimp immune system defense responses and allow White Spot Syndrome Virus (WSSV) replication (Vidal et al. 2001). Dietary protein quality and quantity during cold stress should be given more attention during feed formulation (Zhou et al. 2011). Free Amino Acids (FAAs) play important roles, such as functional substrates or energy utilization, for the animal to sustain prolonged and intensified cold stress. Vectors of Viral Infections The Red Sea and Gulf of Aden Region is an ocean gateway between the Indian Ocean and the Atlantic Ocean through the Mediterranean Sea (Gerges 2002). The Red Sea was one of the least ecologically disturbed seas relative to other enclosed and semi-enclosed seas until the opening of the Suez Canal. Growing maritime transport through the Red Sea, an international waterway, poses an increasing bioinvasion risk to the region’s Can the Blue Revolution with Shrimp in Saudi Arabia Cross the Disease Chasm? M.R. Kitto 1 waters and marine resources. Based on genotyping analyses, new WSSV and TSV genotypes have been found in Saudi Arabia, suggesting that they derived from wild F. indicus from the Red Sea that were used for broodstock (Kathy et al. 2012). Furthermore, shrimp subpopulations are mixed by southward currents along the east African coast (Kathy et al. 2012). Different species of macroinvertebrates can potentially introduce disease organisms (Payen and Bonami 1979). The estuarine mud crab Rhithropanopeus harrisii, for example, commonly carries strains of the white spot baculovirus (Payen and Bonami 1979). Farasan Island (southern Red Sea) is surrounded by some 90 islands to which thousands of birds migrate annually from other parts of the world. If a viral disease outbreak occurs at one farm in Gizan (southern Red Sea), the disease could easily be spread to nearby farms by seabirds (Vanpatten et al. 2004). Infectious Taura syndrome virus was present in the feces of seagulls that were collected during a disease epizootic in Texas (Garza et al. 1997). About 1,050 nests were once counted in three large active coastal bird colonies of cattle egret Bubulcus ibis in Qunfudah and Al Lith (Newton and Al Suhaibany 1996). Demoiselle cranes Anthropoides virgo, migrating through Saudi Arabia, add to the shrimp disease risk from birds (Newton and Symens1993). Vectors of WSSV include rotifers and their resting eggs, marine molluscs, polychaete worms and non-decapod crustaceans, including Artemia salina and the copepods, as well as oncrustacean aquatic arthropods such as sea slaters (Isopoda) and Euphydradae insect larvae. Polychaete worms are possible vectors and reservoirs for WSSV in shrimp ponds and the surrounding seawater environment (Vijayan et al. 2005). The virus has the potential to persist in the surrounding canal environment for at least a year after an outbreak of WSSV in shrimp culture ponds (Quang et al. 2009). In Saudi Arabia, post-harvest dry-out was practically not feasible for huge farming ponds, not to mention the year-round wet feeder and drain canals. WSSV can be present in cultivated shrimp without any noticeable disease outbreak (Tsai et al. 1999). The phenomenon of fairly good tolerance to two or more viral pathogens is poorly We are witnessing the rise and apparent fall of the blue revolution with shrimp in the Kingdom of Saudi Arabia. Shrimp culture in Saudi Arabia started in 1983. Unlike Iran, where there is a directed development approach to benefit smallholders, in Saudi Arabia it has been purely a private sector initiative involving large companies. Presently Indian prawn farming is negotiating a crucial uncertainty in the Kingdom. Low stocking density and stricter biomass thresholds could not prevent viral diseases from wiping out shrimp crops. The storm cloud of cryptic infections in shrimp won the game. Three decades of global investigation into the immunity of penaeid shrimps provided no help to keep culture going. Can Indian prawn endure the viral battle?
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