Water spirits within the fishers' worldview: implications for fishing management in Northeast Brazil.

Background: Historically, aquatic environments are linked to the worldview of many local people, where there is an interconnection between the natural world, the supernatural, and the social organization. In this study, we provided a discussion on how the supernatural beings that inhabit the freshwater systems interact with artisanal fishers and fishing resources in the riverine community of Parnaíba River middle course, in Mid North of Northeast Brazil. We also provided the implications of these interactions on the fisher's behaviors and how the acculturation process (e.