*Ecological and Social Impacts of Aquacultural Introduction to Philippines Waters of Pacific… DOI: http://dx.doi.org/10.5772/intechopen.91775*

concern. This review paper aimed to evaluate the ecological and social impacts of aquacultural introduction to the Philippines waters of Pacific whiteleg shrimp *P. vannamei*. Several questions were answered and discussed based on literature, scientific details, reflections on personal experience, and their relevance to aquaculture of the *P. vannamei* in the Philippines to evaluate the ecological impacts, while social impacts were discussed based on literature. Findings revealed the escapes of *P. vannamei* from aquaculture production facilities of several countries into non-native waters including the Philippines. The presence of *P. vannamei* in the wild was due to the intentional release in attempts to escape detection during the implementation of a ban on the importation of all live shrimp in the Philippines and also possibly due to escapes from intensive and expanding production cycles as well as natural calamities such as floods. Consequently, the ability of *P. vannamei* escapees to survive the natural environmental conditions due to their tolerance to a wide range of salinity and pH could lead to ecological concerns such as resource competition, reproduction, and spread of disease in the wild. Studies reported that *P. vannamei* could potentially interact with local species through food competition, either by exploitative or interference competition. While there is no evidence that *P. vannamei* can establish population outside of its natural geographic range, natural reproduction of escapees is still possible once released mature adults could find mates in the wild. Thus, if the frequency of escapes is increasing and when they begin to reproduce successfully, the non-native shrimp *P. vannamei* could become a serious threat to native shrimps. The most problematic consequence of *P. vannamei* farming is the spread of the alien pathogen, Taura syndrome virus (TSV), which is rapidly spread due to international trade and now widely distributed in the shrimp-farming regions of the Americas, Southeast Asia, and the Middle East. The proliferation of TSV in *P. vannamei* farming has resulted in catastrophic losses and transmission of the disease in the wild wherein crustaceans (other shrimps and crabs) including fish (Asian sea bass) can be infected. In the Philippines, TSV presence in farmed *P. vannamei* was reported for the first time since its introduction in the 1970s. On the other hand, there is no specific information on the social impacts of *P. vannamei* farming; however, the recent expansion of shrimp culture has resulted in social conflicts with other resource users.

This review shows the negative implications on the aquacultural introduction of Pacific whiteleg shrimp *P. vannamei* in the Philippines both ecological and social aspects, and this heightens important management issues. Below are recommendations to ensure sustainable farming of *P. vannamei* in the Philippines:


*Spatial Variability in Environmental Science - Patterns, Processes, and Analyses*

have illegal *P. vannamei* farms operating in Luzon. Moreover, despite all the efforts of the BFAR, the culture industry for the shrimp in the Philippines has grown and may produce as much as 5000 metric tons in 2003 [29]. In fact, Philippines was one of the main producer countries of *P. vannamei* based on FAO fishery statistics in 2006 [73]. According to de la Peña [74], there is always the possibility of contamination with TSV if the illegal shipments of the shrimp remain uncontrolled, and this proves recently as the study of Vergel et al. [75] reported for the first time the presence of TSV in *P. vannamei* in the Philippines using morphological and molecular techniques. BLASTn search results showed that the TSV sequences have very high sequence similarity at 86–100% with TSV viral isolates from other countries (Taiwan, Thailand, Venezuela, the USA, Colombia, and Belize). The detected prevalence rates of the study comprise a small sample population with limited areas in the Philippines, namely, Bulacan (33%), Batangas (47%), Bohol (7%), and Cebu (13%). The authors suggested further testing in other sites in the country and implementation of mitigation methods and policies to prevent further spread of the viral disease. Likewise, detection of TSV in the wild is also important to be conducted. In the study of Barnette et al. [76] using PCR and immunological analyses, results suggested that TSV has already spread into the Bangpakong River and the Gulf of Thailand. The viral disease appeared to be more widespread in dry seasons than wet seasons. The presence of TSV has been detected in *P. monodon* adults; local shrimp species of the Bangpakong River such as *P. monodon*, *P. semisulcatus*, *P. merguiensis*, *M. brevicornis*, *M. affinis*, *M. tenuipes*, *Parapenopsis hungerfordi*, and *M. rosenbergii*; two other species belonging to the Family Caridea; and wild-caught *P. vannamei* including green mussel *Perna viridis*, blue swimming crab *Portunus pelagicus*, and Asian sea bass *Lates calcarifer*. TSV was detected in *L. setiferus* and *Farfantepenaeus aztecus* in Laguna Madre [77] and *L. schmitti* in Maracaibo lagoon, Venezuela [78].

With or without valid arguments, aquaculture has been accused to be the cause of many problems such as environmental, economic, inclusively esthetic, and social impacts [79]. In Vietnam, social impacts associated with shrimp farming include the increase of poverty and landlessness, food insecurity, and impacts on health and education [80, 81]. While there is no recent information regarding the social impacts of shrimp farming particularly the use of alien species such as the *P. vannamei* in the Philippines, Primavera [82] reported that the social costs of intensive prawn farming include the reduction of domestic and agricultural water supplies, decline in quantity of food fish, marginalization of coastal fishermen, displacement of labor, and credit monopoly by big businessmen. The capital-intensive nature of high-density shrimp culture has favored the entry of multinational corporate investors or the national elite. They can provide the necessary capital; have easier access to permits, credits, and subsidies; and can absorb financial risks which are disadvantaged to local communities in coastal areas and small farmers [83]. One main issue in the recent expansion of shrimp culture is social conflicts with other resource users; however, the shrimp culture industry employs thousands of rural

The presence of Pacific whiteleg shrimp *P. vannamei* in the Philippines has already reached more than five decades, and this raises ecological and social

people, and it would be far worse off without it [73].

**8. Conclusion and recommendation**

**150**

**7. Social impacts**

