Upwelling
The major upwellings in the ocean are associated with the divergence of currents that bring deeper, colder, nutrient rich waters to the surface. There are at least five types of upwelling: coastal upwelling, large-scale wind-driven upwelling in the ocean interior, upwelling associated with eddies, topographically-associated upwelling, and broad-diffusive upwelling in the ocean interior.
Discus (fish)
"Symphysodon" species inhabit the margins of floodplain lakes and rivers in the lowland Amazon basin, where it is part of the highly diverse Neotropical fish fauna. "S. discus" is restricted to blackwater habitats, but periodically these may experience brief floods of whitewater. "S. tarzoo" is found in both black and whitewater, and "S. aequifasciatus" also occurs in clearwater. Because of their preference for lentic habitats such as floodplains and flooded forests, whitewater inhabited by discus contain little suspended material (unlike main sections of whitewater rivers).