Scientists urge outcome-based, watershedwide approach to restore the Chesapeake

More than twenty years after the historic Chesapeake Bay Agreement set out a roadmap for a coordinated clean-up effort at state and federal levels, the region is struggling to follow it, scientists say.

Panelists speaking at a February 20 session of the American Association for the Advancement of Science (AAAS) in Washington, DC emphasized the importance of an adaptive approach to restoration in the Chesapeake––which scientists call adaptive management, in which ideas and approaches can be tested, checked for success, and adjusted along the way. “We are headed in the right direction, we know where we want to go, but need to be more efficient and accountable in order to get there,” says Donald Boesch, president of the University of Maryland Center for Environmental Science.

And this modify-as-you-go approach to restoration should be “watershedwide,” panelists say, including upland streams and rivers, not only the Bay and its living resources––such as crabs, oysters, and underwater grasses. “What happens every day in backyards and on street corners that are miles and miles from the Bay proper have huge impacts on Bay health,” according to ecologist Margaret Palmer from the University of Maryland, College Park. “Restoration of the Bay will not occur unless we stem the loss of headwater streams and freshwater wetlands and restore non-tidal waters,” Palmer says.

Palmer is working on the large-scale National River Restoration Science Synthesis Project, to inventory and evaluate ongoing stream and river restoration projects in the Chesapeake watershed. She analyzed existing written records and found that fewer than 5% of these projects have been evaluated for success after completion, a significantly lower percentage than other regions in her analysis. The panel also addressed the need for a watershedwide approach to limit nitrogen input to Chesapeake Bay––which causes the excessive growth of algae and leads to the depletion of oxygen in the bottom layers as it dies, falls to the bottom, and decomposes.

Agricultural fertilizer runoff plays a dominant role in contaminating the Bay with excess nitrogen and has long occupied center stage in restoration efforts. But emissions to the atmosphere from cars and stationary sources, deposited later on the landscape, may be more significant than previously thought, according to biogeochemist Robert Howarth from Cornell University in Ithaca, NY. Climate change will further compound the nitrogen problem in the Bay, Howarth reports. In the absence of management actions, nitrogen flux down the Susqhehanna River, the Bay’s largest tributary, could increase as much as 17% by 2030 and up to 65% by 2095 due to predicted warmer, wetter conditions, he finds.

So what approach can scientists, managers, and citizens take to reverse the Bay’s downward spiral?

“We must think across the boundaries that traditionally lead to disjointed, uncoordinated efforts in freshwater and coastal systems,” says Jonathan Kramer, session organizer and director of the Maryland Sea Grant College, part of a network of 30 university-based programs that support innovative marine research and education.

“We have plotted a good course for restoration. What we need now is a method of course correction that encourages us to make adjustments along the way,” Kramer says.