60 JUNE 2018 • WORLD AQUACULTURE • WWW.WAS.ORG The Philippine Freshwater IAFS Scenario According to reports by Juliano et al. (1989), Joshi (2006) and Guerrero (2014), 62 freshwater fish species have been introduced into local waters since 1905 for a variety of purposes, including aquaculture, ornamental, recreational, and biological control. Of these introductions, ten can be classified as invasive and an additional four have the potential to be invasive (Table 1). One of the easily observed trends is that 11 of 14 invasive and potentially invasive species were introduced directly for ornamental purposes, without much record of the year of introduction, pointing in the direction of their accidental release into Philippine waters. This is not unexpected because almost one-third of the top 100 worst invasive species in the world listed by the International Union and that these alterations can occur over much shorter time intervals (Mooney and Cleland 2001, MacKinnon 2002, Huey et al. 2005). The consequences of uncontrolled IAFS population increase and spread in the Philippines has the potential to be economically deleterious. The Philippine fishing and aquaculture industry provided 1.8 percent of the national gross domestic product in 2012 and employed 1 million people in 2010, producing US$ 1.2 million worth of fish and fishery products for export in 2013 (FAO 2014). Data on the economic impact of IAFS introductions is not comprehensive or complete, limited to unconsolidated reports (Joshi 2006, Guerrero 2014). Damages are not only due to losses of commercially important fish species; the hidden consequences on the environment are also a major concern because, once established, IAFS are almost impossible to completely eradicate (Gozlan et al. 2010). TABLE 1. Invasive and potentially invasive freshwater fish species in the Philippines (Guerrero 2014). SPECIES ORIGIN YEAR STATUS Invasive Channa striata mudfish Malaysia 1908 C, EN, W Channa micropeltes giant snakehead Thailand U O, EN, W Chitala ornata clown featherback Thailand U O, EN Clarias batrachusa Asiatic catfish Thailand 1972 C, EN, W Monopterus albus rice paddy eel Malaysia U C, EN, W Parachromis managuensis jaguar guapote Central America U O, EN, W Pterygoplichthys disjunctivus vermiculated sailfin catfish South America U O, EN, W Pterygoplichthys pardalis Amazon sailfin catfish South America U O, EN, W Sarotherodon melanotheron black-chinned tilapia U U O, EN, W Clarias batrachus Asiatic catfish Thailand 1972 C, EN, W Potentially Invasive Arapaima gigas arapaima South America U O, EN Chitala chitala clown knifefish Thailand U O, EN, W Cichla occularis peacock bass Central America U O, EN Pygocentrus nattereri red-bellied piranha South America U O, EN C-cultured O-ornamental EN-natural breeding W-found in wild U-unknown Peacock bass Cichla ocellaris caught on a fish farm in Laguna, Philippines. Photo: Bettina Salvador.
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