Fishers’ knowledge on the ecology, impacts and benefits of the non-native peacock bass Cichla kelberi in a coastal river in southeastern Brazil

Abstract

Ethnoichthyology has been used to understand how humans perceive environmental changes, including species introductions. In Rio de Janeiro State, southeastern Brazil, fishers introduced juveniles of peacock bass Cichla kelberi in the Juturnaiba Reservoir in the 1990’s. In the last years, this fish started to be caught in the Sao Joao River, downstream of the dam. This study aimed to identify whether fishers recognize the potential impact of the peacock bass over the native species, to understand the economic valuation they made to the services provided by this species, and if they include management of the non-native peacock bass in their practices. Semi-structured interviews with artisanal and sport fishers were employed between September and October 2016. A total of twenty-five interviews were carried out, 12 with artisanal and 13 with sport fishers. In general, fishers expressed knowledge about biological and behavioral aspects of the peacock bass, but opinions diverged on its impact over the native ichthyofauna. Differently from the artisanal, most sport fishers do not relate the decline in the population of other native species to the occurrence of the peacock bass. Instead, they mention other anthropogenic impacts in the Sao Joao River basin. The later advocate the practice of fish and release for the peacock bass, in order to maintain their population in the study area. The ethnoichthyological knowledge gathered from fishers provide novel information related to the native ichthyofauna, peacock bass introduction and other anthropogenic impacts, and might constitute a powerful tool to the development of sustainable strategies.