Importance of protection strategies in the conservation of the flagship species “dourado” Salminus brasiliensis (Characiformes: Bryconidae)

Abstract

In the upper Paraná River floodplain, the populations of Salminus brasiliensis have been subjected to several anthropic impacts, such as overfishing, the blocking of migratory routes by dams, and regulation of the flood regime. Its populations have disappeared or become depleted in most rivers in this basin. These populations are the target of protection measures aimed at restoring them. This study evaluated the abundance of this species in the upper Paraná River floodplain over a 26-year time series in sites under different degrees of protection. Despite the overall decrease in the abundance of S. brasiliensis across the region, the less impacted sites have higher abundances and exhibited a slower decline in the probability of occurrence. Over time, populations in less impacted sites also exhibited improved fish condition. Some protected areas in the upper Paraná River have had a mitigation effect by lowering the velocity of population decline and representing a constant source of propagule production for other areas. Our results reinforce the notion that populations threatened with low abundances take a long time to effectively recover their stocks. Thus, besides evaluating species conservation strategies, long-term studies are essential to subsidize management measures, such as fisheries regulations.

Diet of Moenkhausia bonita (Benine, Castro & Sabino 2004) (Characiformes: Characidae) in streams in the basin of rio Formoso, Brazilian Midwest

“…Dietary ontogenetic changes can reduce intraspecific competition and allow species to successfully establish themselves in environments (Alves et al 2021). Understanding the relationships between fish fauna and the environment is essential to assist in methods of conservation and environmental restoration (Ferreira & Casatti 2006;Dias et al 2022). The studies on the trophic ecology of fish are of paramount importance to know both individual and community processes, being important aspects for the conservation of species (Nunn et al 2012;Tonella et al 2019).…”