Research on dams and fishes: determinants, directions, and gaps in the world scientific production

Despite the socio-environmental importance of ichthyofauna, global fish biodiversity has decreased, and the damming of rivers is one anthropogenic activity that causes this reduction. This scientometric study evaluates the main determinants, directions, and gaps of scientific research on the biodiversity of fishes that are influenced by dams. Between 1991 and 2016, there was an increase in the number of studies about this topic, in proportion to the total number of studies that were evaluated. The distribution of these studies among countries is not random, since some socioeconomic and environmental factors (e.g., gross domestic product, number of researchers, number of large dams) determine the distribution of research. Moreover, these studies mostly address the negative impacts of dams on fish communities on a local scale; several studies have shown the importance of mitigating these impacts. In this particular study, we emphasize the need to research the effects of fishing, cascading dams and the phylogenetic diversity of ichthyofauna. We find that the relationship between dams and fish has become popular among researchers, in particular those who are willing to understand the causes, consequences, and severity of these changes on the ichthyofauna.