Woods Hole Research Center

To a large degree, river water chemistry is a function of processes occurring in the river’s watershed. As a result, changes on land also lead to changes in river chemistry. Much as human health can be evaluated by analyzing blood chemistry, so too can watershed health be assessed by monitoring river water chemistry. Because river inputs to the ocean also impact ocean processes, changes on land are also altering the marine environment.

Map of watersheds: Colored watersheds indicate active study sites, gray watersheds are priorities for expansion. Click image for larger version.

Scientists from the Woods Hole Research Center and Woods Hole Oceanographic Institution have joined with numerous collaborators around the world to investigate river chemistry and land-ocean linkages in Earth’s most significant river systems. Now active in 12 watersheds around the world – with the goal of expanding to several more - the Global Rivers Observatory is measuring concentrations of carbon, nitrogen, phosphorus, and other naturally occurring compounds in the rivers near their mouths where they empty into the ocean. Samples are also being collected from key tributaries upstream in the watersheds to investigate how chemical signatures vary regionally or in areas with differing land cover or land use.

WHRC Scientists Paul Mann, John Poulsen, and R. Max Holmes

For example, during their February 2010 expedition to the Congo River watershed, Woods Hole Research Center scientists Max Holmes, Rob Spencer, Paul Mann, and John Poulsen, in collaboration with Congolese scientist Bienvenu Dinga, sampled more than 30 tributaries of the Congo River. Much of the sampling was done from piroques, traditional wooden dugout canoes.

The Global Rivers Observatory is improving understanding of how climate change, deforestation, and other disturbances are impacting river chemistry and land-ocean linkages. This information is vital for tracking the health of Earth’s watersheds and for predicting how Earth’s water and chemical cycles will change in the future.

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Video and Photographs, including thumbnail, © Chris Linder.

The Global Rivers Observatory is supported by NSF and Harbourton Foundation.