Despite occurring in a large river basin, the polkadot stingray has a relatively restricted range (limited to the Xingu River Basin), and serious impacts in this region may result in population declines.
Habitat loss/degradation involving the development and expansion of agriculture, livestock, ongoing gold mining, fisheries and logging are a threat to this species. Water contaminants originating mainly from agricultural, domestic, sediment, sewage and solid wastes, as a consequence of this development, are also considered threats for P. leopoldi.
Inadequate land management and deforestation, mainly in the Xingu River headwaters and some of its tributaries, are significantly increasing and could bring serious impacts to the entire basin.
Geological characteristics of the Xingu River favour the building of dams throughout the basin and potentially represent a threat to this species; however, it is uncertain how P. leopoldi populations will be affected by this impact. Genetic isolation is likely to take place if the proposed dams of the Belo Monte Hydroelectric Complex are built in the near future.
Human settlement, tourism and recreation often lead to persecution (killing freshwater stingrays due to fear of sting injuries).
This species is seldom used as a food source but is captured as bycatch (mainly by hooking, netting, entanglement and occasionally by poisoning) in other target species fisheries.
Juveniles are captured for the international ornamental fish trade and at present this activity is regulated by an export quota system that must be correctly enforced by the environmental and export related national agencies. It is important to note that captures for ornamental purposes represents an important socio-economic activity for riparian residents in this region.
Historically, severe droughts (associated with the El-Niño phenomenon) in some small tributaries of the Xingu river have caused high mortality (Charvet-Almeida, pers. obs.).