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.
Lake Erie Basin
New York's drainage basin covers .Agricultural, industrial, and residential land use are the primary nonpoint sources of pollution in the Lake Erie Basin. National and state environmental agencies, as well as interstate and binational cooperative efforts, focus on water quality, especially since the freshwater lake is used extensively for drinking water, recreation, and the fishing industry. Habitat and flow alteration cause siltation and sedimentation issues which can require dredging. Fertilizer runoff from farms and residences and unplanned releases from sewage treatment plants promote eutrophication through nutrient and organic enrichment, bacterial contamination, and the appearance of ammonium hydroxide. Industrial land use adds metals that flow into the basin and cause sediment contamination.