Regional distribution of Secchi disk transparency in waters of the United States

Individual Secchi disk measurements (975,760) were gathered from across the United States to understand regional distribution in water transparency. Compiled Secchi disk measurements represented 14,421 US waterbodies. Average water transparency ranged from 3.5 m) were in Alaska, Maine, Montana, New Hampshire, and Vermont. Regional differences in water transparency were identified across the US Environmental Protection Agency ecoregions (Level III), with lower water transparencies occurring in nutrient-rich regions and higher water transparencies occurring in nutrient-poor regions. Reg...