Therefore, water with little or no CDOM, such as the open ocean, appears blue. Waters containing high amounts of CDOM can range from brown, as in many rivers, to yellow and yellow-brown in coastal waters. In general, CDOM concentrations are much higher in fresh waters and estuaries than in the open ocean, though concentrations are highly variable, as is the estimated contribution of CDOM to the total dissolved organic matter pool.
Consequently, water with minimal or no CDOM, such as the open ocean, exhibits a blue hue. Waters containing substantial amounts of CDOM can display shades ranging from brown, similar to many rivers, to yellow and yellow-brown in coastal areas. Generally, CDOM concentrations are significantly higher in fresh waters and estuaries compared to the open ocean, although these concentrations exhibit considerable variability, as do the estimated contributions of CDOM to the total dissolved organic matter pool.