Societal perception, impacts and judgment values about invasive freshwater stingrays

Abstract

We currently face a unique phase in the global biodiversity crisis because of massive introductions of non-native species into greatly altered ecosystems. These introductions frequently occur as a consequence of human constructions and structures such as dams that allow species to overcome historic established biogeographic barriers. There is a pressing need for study the socio-economic influence of invasive populations. Here we assessed the effects of one of the largest invasion events of elasmobranchs in the world. We investigated socio-economic impacts caused by invasive populations of freshwater stingrays in the upper Paraná River ecoregion (Brazil) using questionnaires to survey 125 artisanal fishers. The two study species are not tradable, may damage gear and cause accidents directly linked with their presence in the ecosystem, so are associated with economic losses for fishers. Thus, the local population perceives stingrays as a bycatch with strong negative socio-economic outcomes. Our results indicate that large-scale invasions triggered by enterprises (e.g. dams) can misguide conservation policies and management and cause multilevel damages to human well-being, especially if local information and local perception are not taken into account. The assessment of social perception demonstrated that invasive stingrays are not welcome or beneficial for the traditional resident human population.