Potential invasive non-native fish farmed in the coastal region of Rio Grande do Sul, Brazil

Abstract

Freshwater fish aquaculture in Brazil is based in a few species, mostly introduced from other countries or continents. When an exotic species is introduced into the ecosystem, there are a risk that this specie will escape in a natural system, resulting in a possible detrimental effects to native species or even to the ecosystem functioning. In order to provide the public managers decisions about which species should be ecologically suitable for use in aquaculture in the coastal region of the Rio Grande do Sul State, this study classifies the invasive potential of several fish species used in inland aquaculture in the region. The list of species cultivated in the region was obtained by a literature review and consultation of agricultural extension agencies or institutions that provides technical assistance and serve as intermediaries in the purchase of fingerlings. The protocol Fish Invasiveness Screening Kit - FISK was applied to classify non-native species according to invasive potential. Ten non-native species are cultivated in the region. Ctenopharyngodon idella, Cyprinus carpio, Hypophthalmichthys molitrix, H. nobilis, Ictalurus punctatus and Oreochromis niloticus presented a high invasive potential, scoring between 22 and 38, while Pseudoplatystoma fasciatum, P. corruscans, Piaractus mesopotamicus and Hoplias lacerdae presented medium invasive potential, scoring between 9 and 15. The species with high potential should compose a "black" list and have its use prohibited. For the species with medium invasive potential, further studies should be applied in order to determine the danger or not of its use in aquaculture in the region of Patos Lagoon.