Over the centuries, New York's Hudson River has borne a nation's cargo, inspired its first unique art tradition, and absorbed the detritus of millions of people within its watershed.
Now, the 315-mile waterway is slated to undergo the most intense scientific scrutiny of any major river in the United States. Not only will the project offer fresh insights into how river systems work, it will also give researchers key data and warnings about environmental threats to the nation's mid-Atlantic coast.
The effort is perhaps the most visible sign yet that resource managers and researchers have come to recognize that the health of US coastal waters depends in large degree on the ecological vitality of the rivers that flow into them.
For the past decade, marine scientists and the federal government have worked to build a network of coastal and ocean observatories. Two weeks ago, a consortium of the nation's leading ocean research centers awarded a $97.7 million contract to the Woods Hole Oceanographic Institution in Woods Hole, Mass., and two other institutes to develop and maintain the undersea hardware needed to field a network of coastal and global sensors. With the Hudson River project, dubbed the River and Estuary Observatory Network, such efforts are now set to push deep into the country's interior.
With a watershed that encompasses some 13,500 square miles and embraces 12 million people, "our river system is under constant human stress," says John Cronin, director of the nonprofit Beacon Institute for Rivers and Estuaries in Beacon, N.Y. The project "will help solve the problems and answer the management questions that haunt an ecosystem like the Hudson."
Under the aegis of the institute, several major research institutions, the National Marine Fisheries Service, and IBM have joined forces to set up a comprehensive environmental monitoring network along the waterway. It's being designed to track changes in everything from water chemistry and the flow of sediment and pollutants downstream to monitoring the movement of fish and their larvae.
The goal is twofold. The collaboration aims to develop a deeper understanding of how human and natural activities affect a river's ecological health. The team aims to design a sensor network that can be adapted to managing rivers worldwide. And in the process, they plan to build a monitoring and forecasting system that will give state and local officials the ability to see changes in a river's condition as they happen, as well as conduct modeling exercises to help resource managers find the most ecologically responsible practices for sustaining a river's health.
Last month, the project passed a milestone when the Beacon Institute and IBM announced an agreement under which IBM will provide the data-processing system to gather and analyze vast amounts of video, acoustic, and other data as it arrives from sensors.
The idea of monitoring river flow or taking sediment samples is hardly new, acknowledges Oscar Schofield, a Rutgers University professor who works on ocean-observing networks. But the efforts often are piecemeal.
Far more is needed, he says, including networks that run continuously and reach far into the surrounding watershed, to truly understand how a river works as a system.
For instance, scientists are trying to establish better ways to estimate such basic features as how changes in flow rate affect changes in sediment levels the river carries. Municipal water-supply managers are keenly interested in such mundane things because it affects the type of purification strategies they need to employ, especially if upstream sediments contain contaminants.
Nailing down that relationship is "one of those holy grail-type items," says Rocky Geyer, a senior scientist at the Woods Hole Oceanographic Institution. Scientists have a basic mathematical rule of thumb they use to relate sediment loads to flows. But it takes long-term, detailed monitoring of five-, 10-, or 100-year floods to test how well that relationship holds up under extreme events.
Shipping companies also are excited by the prospect of having the network in place, adds Dr. Schofield, because they feel they often get blamed for dumping pollutants that may have come from elsewhere. A dense network of sensors could help determine if raw sewage in the water may in fact come from a nearby broken main, rather than from a ship's sanitary tanks.
Indeed, Schofield says, one of the challenges for the Hudson project will involve figuring out how to add what he calls the "human box" to the many other factors affecting the river – an ability to track and eventually model human interactions with the Hudson. The results would be blended with those from other biological, chemical, and physical calculations that simulations of the river would require. "If we're able to do that in 20 years," he says, "that would fundamentally change how we view our Earth and our world."