Impacts of Non-Native Fish Species in Minas Gerais, Brazil: Present Situation and Prospects

Abstract

For some time, the rate of non-native fish introductions has been increasing in South America. There are many reasons for introductions: reservoir stocking programs, aquaculture, sport fishing, control of disease vectors, and the pet trade. Accidental escapes also contribute significantly. In Brazil, despite federal and state regulations, there are misunderstandings about such concepts as native, exotic, allochthonous, or autochthonous fishes and introductions, translocations, reintroductions, and transfers of fishes. Known impacts of exotic fishes include native species extinction, changes in competition and predation rates, limnological perturbations, introduction of diseases and parasites, hybridization with native species, and changes in fisheries composition. The few recorded benefits of non-native species introductions are restricted to the improvement of fish production and sport fisheries. In Minas Gerais, Brazil, records of exotic species have increased over the past seven years. In some of the most important river basins of that state, alien fish species might represent up to 40% of the fish fauna. Congeneric species, such as Hyphessobrycon bifasciatus and the exotic H. eques, can be captured from the same water body and the non-native species can be much more abundant than the native species. The recent introduction of Leporinus macrocephalus from the Pantanal may cause the same impact to the native L. copelandii. The widespread introduction of the peacock bass and other piscivorous species is the cause of local extinctions in the central lake of Lagoa Santa and in the Theresa M. Bert (ed.), Ecological and Genetic Implications of Aquaculture Activities, 291-314. ß 2007 Springer.Rio Doce valley lakes. Genetic problems can also be foreseen with the release of hybrids of Pseudoplatystoma corruscans and P. fasciatum in areas where only the first species naturally occurs. Tilapine species, the most widely distributed exotics within the state, have had negative impacts on fisheries and on fish species compositions in reservoirs. Solution to these problems must involve the following: (1) better enforcement of legislation governing the sale and transport of live organisms, (2) development of native-species aquaculture, and (3) public awareness programs on the adverse impacts of exotic species to the native fish fauna.

Spatial variations in fish assemblage structure in a southeastern Brazilian reservoir

“…Both species were also found downstream in Itumbiara (Vono, 2002) and Capim Branco (Rêgo, 2008) Reservoirs. The presence of alien species is widely reported in other reservoirs located in the Upper Paraná Basin (Gomes and Miranda, 2001;Alves et al, 2007;Carvalho and Silva, 2007). Introductions and establishment of Cichla species were also mentioned (Oliveira et al, 2003;Luiz, 2010) as was the suppression of the local fish fauna (Pelicice and Agostinho, 2009).…”

Colorful invasion in permissive Neotropical ecosystems: establishment of ornamental non-native poeciliids of the genera Poecilia/Xiphophorus (Cyprinodontiformes: Poeciliidae) and management alternatives

“…Preventing incursions of organisms outside of their native ranges is the most cost-effective way 11 e160094 [11] and public policies are needed to protect Brazil's headwater creeks from future introductions of new stocks of poeciliids and other non-native species. Ornamental aquaculture, as the main cause for poeciliid presence and spread throughout Brazil (Bizerril, Lima, 2001;Castellani, Barrella, 2006;Alves et al, 2007;Magalhães, Jacobi, 2008), should be controlled more carefully. We echo recommendations of Courtenay et al (1974) in rerouting all effluent waters from fish rearing facilities through a dry well, and installation of adequate sand and gravel filter to allow passage of water but not livestock.…”

“…Although more than 50 non-native fish species are currently found in Brazilian headwater creeks (Bizerril, Lima, 2001;Magalhães, Jacobi, 2008), a group of seven poeciliids deserve special attention as a threat to native communities due to negative impacts such as changes in the structure of the native fish assemblages and biotic homogenization: the guppy Poecilia reticulata Peters, 1859, sailfin molly P. latipinna (Lesueur 1821), black molly P. sphenops Valenciennes in Cuvier, Valenciennes, 1846, Yucatan molly P. velifera (Regan 1914), green swordtail Xiphophorus hellerii Heckel 1848, southern platyfish X. maculatus (Günther 1866), and variable platyfish X. variatus (Meek 1904) (Alves et al, 2007;Magalhães, Jacobi, 2008;Magalhães et al, 2011). Along with cyprinids, cichlids and osphronemids, these poeciliids are the ornamental fishes most sought by the Brazilian aquarium trade (Coe et al, 2011;Magalhães, Jacobi, 2013b;Assis et al, 2014;Garcia et al, 2014).…”

“…Along with cyprinids, cichlids and osphronemids, these poeciliids are the ornamental fishes most sought by the Brazilian aquarium trade (Coe et al, 2011;Magalhães, Jacobi, 2013b;Assis et al, 2014;Garcia et al, 2014). They all have been introduced into headwater creeks of the southeastern region mainly as by-products of aquaculture-related activities (Bizerril, Lima, 2001;Castellani, Barrella, 2006;Alves et al, 2007;Magalhães, Jacobi, 2008). Poeciliidae, however, has been identified as one of the top invasive freshwater fish families and is linked to reduction in zooplankton, damselfly/dragonfly populations, decline and extinction of native fishes and also to negatively impact native amphibians by preying on amphibian eggs and larval stages in several regions of the world (Stockwell, Henkanaththegedara, 2011).…”

Knodus moenkhausii (Characiformes: Characidae): one fish species, three hydrographic basins - a natural or anthropogenic phenomenon?

“…It is a plausible explanation for K. moenkhausii which is traded as an ornamental fish due its small size and attractive coloration in aquariums, although it is traded in relatively low numbers (data from Ministry of Development, Industry and Foreign Trade of Brazil -MDIC -2012). The ornamental fish trade has been reported as the cause of many species introductions, for example in the Upper Paraná River basin where eleven fishes species were introduced [6,65] and the São Francisco river basin, where seven species were introduced [7]. The Paraíba do Sul River basin is documented to have 56 introduced species [66].…”