When too much nitrogen enters the Chesapeake Bay, it can fuel the growth of harmful algae blooms that block sunlight from reaching underwater grasses and create low-oxygen areas, or “dead zones,” that suffocate marine life. But some key successes in curbing the amount of nitrogen entering local waterways have a potentially surprising source—the Clean Air Act.
In a factsheet released last week, the U.S. Environmental Protection Agency (EPA) outlines how declines in air pollution have substantially reduced the amount of airborne nitrogen that ends up in the Bay, helping the agency and its partners stay on track to meet the water quality goals of the Total Maximum Daily Load (TMDL), or “pollution diet,” which representatives from across the Bay region recommitted to achieving as part of the Chesapeake Bay Watershed Agreement.
Polluted air can have quite an impact on the health of local waters: scientists estimate that one third of the nitrogen in the Bay comes from the air through a process known as atmospheric deposition. When our cars, power plants or other sources emit air pollution, it can be carried by wind and weather over long distances until it falls onto land or into the water.
“Atmospheric deposition falls everywhere on the Chesapeake watershed, from forests, to fields, to parking lots,” said Lewis Linker, modeling coordinator with the Chesapeake Bay Program. “When this load of nitrogen is reduced, it improves water quality everywhere from stormwater runoff, to small headwater streams, …to the Chesapeake Bay.”
Even pollution emitted thousands of miles away can eventually end up in our waterways. While the area of land that drains into the Bay spans six states and 64,000 square miles, the Bay’s “airshed”—the area of land over which airborne pollutants travel to enter the estuary—is nine times that size. Nearly three-quarters of the airborne nitrogen that eventually ends up in the Bay is generated by sources within this airshed, and the remaining 25 percent is emitted from sources even farther away. Which is why, says Linker, national policies like the Clean Air Act are essential in reducing the amount of pollution that reaches the Bay.
“To restore the Chesapeake, the citizens of the Chesapeake watershed have done a lot of bootstrapped cleanup in their own backyards and watersheds,” said Linker. “But when it comes to atmospheric deposition of nitrogen, the reduction can’t be done by the Chesapeake state partners alone—it’s a job for the whole nation.”
For more on what you can do to curb air pollution, Take Action.
Learn more about the EPA’s efforts to curb nitrogen deposition in the Chesapeake.
Resilience—the ability to successfully adapt and endure against the odds—is a quality we see every year in the vast network of waters and lands that make up the Chesapeake Bay watershed. Each year, the balance between health and degradation continues to be tenuous as the interconnected parts of the ecosystem shift and change in connection with one another. Their variation shows just how dynamic and complex of a system the Bay watershed is.
The Chesapeake Bay Program’s scientific indicators, presented in our latest edition of Bay Barometer, provide a snapshot of how individual parts of this complex system respond to both ongoing challenges and our efforts to protect and repair our natural world. This consistent scientific exploration, in the face of the ever-changing natural factors, provides a basis for clear paths forward in restoration, conservation and protection. With it, Bay Program partners can better understand where and how our work supports the recovery of our lands and waters, adjusting according to need along the way.
How well the region’s landscapes and waters endure and continue to provide life-giving services to our communities is up to us. More than thirty years of Bay Program science has shown that the way we interact with our environment can significantly affect nature’s ability to adapt and recover. Where we poorly build and over-develop our towns, our local natural environments suffer; where we nurture and restore our rivers and landscapes, our communities thrive. Our actions also contribute to the impacts of climate change: rising sea levels, warming streams and more extreme weather events. Healthy waters, forests, farmlands, parks and open spaces in our communities depend on the decisions and choices we make each day.
With wisdom, caring and determination, each of us can be active participants in strengthening the resilience of our environment and continue to enjoy nature’s beauty, bounty and company.
Note: The opinions expressed above are those of the author and do not necessarily reflect U.S. EPA policy endorsement or action.
Our latest look at Chesapeake Bay health reveals an ecosystem in recovery. While the watershed continues to struggle against development, pollution and other challenges, a handful of the environmental indicators presented in Bay Barometer—including American shad, striped bass and underwater grass abundance—have shown signs of resilience.
Released today, Bay Barometer: Health and Restoration in the Chesapeake Bay Watershed offers a science-based snapshot of conditions in the nation’s largest estuary. The data in Bay Barometer reflect the Bay’s health over the course of many years and, in some cases, decades. By tracking changes in this data over time, scientists can better understand ecological patterns and the long-term effects of our restoration work.
According to experts with the Chesapeake Bay Program, the Bay remains impaired. Scientists have seen no significant changes in the last decade of water quality monitoring data and a sizeable drop in the abundance of blue crabs. But communities have continued to reduce the nutrient and sediment pollution that has long plagued the Bay, and some living resources have improved in the face of challenges. Underwater grass acreage has risen 24 percent, American shad have continued to return to their Potomac River spawning grounds and the relative abundance of young striped bass in both Maryland and Virginia waters has recovered from the low numbers seen in 2012.
“The Chesapeake Bay watershed is a vast and complex ecosystem that faces continued challenges,” said Bay Program Director Nick DiPasquale in a media release. “Yet in the face of these… challenges, we are witnessing signs of a system in recovery. And people have the ability to positively affect and help in the recovery process. In fact, we must do so.”
Continuing to investigate the environmental indicators summarized in Bay Barometer will move us toward the ground-breaking goals of the Chesapeake Bay Watershed Agreement, which guides our work to restore, conserve and protect the Bay. In Bay Barometer, we offer our data in their clearest form so you can join our experts in assessing the health of our ecosystem and the progress we are making toward restoring it. Each of the almost 18 million people who live within this watershed can help bring it back to health. To learn more, Take Action.
Bay Backpack, a website for environmental educators in the Chesapeake Bay region, was recently relaunched with a new design, making it even easier for teachers to find resources that bring the Bay and its surrounding lands into their classrooms.
Teachers and educators can use the site’s updated design to find more than 750 lesson plans, books, curriculum guides and other teaching resources that are grouped into themed collections–including Bay animals and habitats, people and culture, Earth system science, land use and water quality. An interactive map of nearly 350 field studies allows teachers to search by location, grade level and subject matter to find hands-on learning opportunities outside the classroom. Bay Backpack also continues to provide a catalog of professional development and funding opportunities that support environmental education efforts, and the new responsive design means users can easily access resources on both desktop and mobile devices, such as smartphones and tablets.
In the recent Chesapeake Bay Watershed Agreement, representatives from each of the six watershed states and Washington, D.C., committed to providing every student in the region with at least one meaningful watershed educational experience, or MWEE, in elementary, middle and high school. Meaningful watershed educational experiences are investigative projects that allow students the opportunity to interact directly with their environment and learn about how the Bay, its rivers and streams and its surrounding lands function as a system. Resources provided through Bay Backpack help teachers from across the Bay area engage students in these educational experiences.
“Bay Backpack is a great tool to help meet the commitments of the new Watershed Agreement,” said Shannon Sprague, Chair of the Chesapeake Bay Program Education Workgroup. “It directly supports our efforts to get every student outdoors and learning about their environment.”
To learn more about what the Bay Program is doing to provide each student in the region with the skills to protect and restore local waters and lands, explore the Environmental Literacy goal of the Watershed Agreement.
Learn more about Bay Backpack and the educational resources it provides.