Chesapeake Bay
Chesapeake Bay
The Chesapeake Bay is the nation’s largest estuary. Its 64,000-square-mile watershed encompasses one of the most economically significant regions of the United States. More than 18 million people live in the Chesapeake Bay watershed. The Chesapeake produces about 500 million pounds of seafood each year, supporting jobs in both commercial and recreational fishing and bolstering the regional economy.
The Bay is a highly valued resource for the region for additional reasons, including tourism, recreational boating, and scenic beauty. In recent decades, the Bay’s biologically diverse ecosystem has seen sharp declines in some of its keystone species, including the native oyster. Human effects on the ecosystem, like overfishing, degraded water quality, and habitat destruction, are significant challenges to the Chesapeake and the species that live there. We work to improve the health of the Bay by using the latest science to ensure its sustainable use for generations to come.
Featured News
![Two sturgeon swim above a gravelly bottom](/s3//styles/inline_field_thumbnail/s3/dam-migration/atlanticsturgeonneargravelbottom.png?h=9e499333&itok=35XtHolx)
![Onboard a boat, a young woman wearing sunglasses and holding a small camera crouches near a frame made from PVC pipe.](/s3//styles/inline_field_thumbnail/s3/2023-12/InternOysterMonitoring.jpg?h=fcfbfced&itok=PhdBDVKy)
![Four young students kneel by a storm drain. They are working on painting the drain with information about the Chesapeake Bay.](/s3//styles/inline_field_thumbnail/s3/2023-11/StormDrainPaintingPACreditElizabethFulton.jpg?h=557039fd&itok=O05q0W_W)
More Information
- About the NOAA Chesapeake Bay Office
- About the Office of Habitat Conservation
- Chesapeake Bay Fisheries Research Grants
- Chesapeake Bay Watershed Education and Training (B-WET) Grants
- Explore the New England/Mid-Atlantic Region
- About the Greater Atlantic Regional Fisheries Office
- About the Northeast Fisheries Science Center
- Diversity & Inclusion Efforts in the Chesapeake Bay
3,600+ species of plants and animals
More than 3,600 plants and animals call the Chesapeake Bay home! The Bay supports an impressive diversity of flora and fauna including 348 species of finfish, 173 species of shellfish, more than 2,700 plant species, and more than 16 species of underwater grasses.
11,684 miles of shoreline
The Chesapeake Bay and its tidal tributaries have 11,684 miles of shoreline—more than the entire U.S. West Coast. But the Bay is surprisingly shallow: its average depth, including tidal tributaries, is about 21 feet. A person who is six feet tall could wade through more than 700,000 acres of the Bay and never get their hat wet.
18+ trillion gallons of water
The Chesapeake Bay holds more than 18 trillion gallons of water! Each day, roughly 51 billion gallons flow into the Bay from its freshwater tributaries.
1.8 degrees
Over the past 30 years, the average water temperature in the Chesapeake Bay has increased by 1 degree Celsius, or 1.8 degrees Fahrenheit. These and future changes threaten coastal communities, aquatic life, and our ability to restore an already stressed system.
Focusing on the Choptank River Watershed
The Choptank River on Maryland’s Eastern Shore, its tributaries, and their watershed are treasured parts of the Chesapeake Bay—and it has been designated as a NOAA Habitat Focus Area. NOAA and partners are restoring habitat, connecting decisionmakers with needed information, and engaging communities as they look to their future.
Exploring Nearshore Fish Habitat in Virginia’s Middle Peninsula
The Middle Peninsula—the watersheds of Virginia’s York and Piankatank rivers and Mobjack Bay—holds habitat including marshes, wetlands, oyster reefs, and underwater grasses. NOAA is working with other federal agencies and other organizations on nearshore habitat restoration and oyster reefs in these vulnerable waters.
Supporting the Chesapeake Bay Program
The Chesapeake Bay Program is a regional partnership of federal, state, and local governments; nonprofit organizations; and academic institutions—all driving toward a healthier Chesapeake. NOAA plays key roles in partnership efforts in fisheries, education, habitat, and climate.
Building an Outdoor Learning Network
NOAA is partnering with several organizations to build a network of school systems and organizations that will deliver meaningful watershed educational experiences to students around the Chesapeake watershed.
Learn more about our work to support student experiences in the Chesapeake Bay watershed
Multimedia
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![Infographic showing the benefits of healthy habitats](/s3//styles/inline_field_thumbnail/s3/dam-migration/ohc_infographic.png?h=148d4d4d&itok=MqT6KNLP)
Healthy Fisheries
![While on a boat, a man wearing a baseball hat, sunglasses, and an orange lifejacket measures an oyster toadfish with a ruler.](/s3//styles/media_750_x500/s3/dam-migration/noaa-scientist-measures-fish.jpg?itok=HpJ9pUik)
As long as humans have lived near the Chesapeake, they have enjoyed eating seafood from the Bay. The Chesapeake is home to 348 species of finfish and 173 species of shellfish. It is a source for both commercial and recreational harvest. Blue crab, oysters, and striped bass are some of the Chesapeake's treasured species. The Chesapeake Bay and its tributaries are also home to species that people do not harvest for food, including the endangered Atlantic sturgeon.
NOAA does not manage fisheries in the Chesapeake Bay; that work is handled by the Maryland Department of Natural Resources, Virginia Marine Resources Commission, and Potomac River Fisheries Commission. But we do play an active role in ensuring the most up-to-date science is available to resource managers and decision makers around the Bay. This supports ecosystem-based fisheries management in the complex and dynamic Chesapeake Bay.
One way we do this is by leading the Chesapeake Bay Program's Sustainable Fisheries Goal Implementation Team, bringing experts together to talk about fisheries science. This team supports the blue crab fishery by issuing an annual Blue Crab Advisory Report that discusses the state of the blue crab population in the Bay. It also tackles emerging challenges, like the invasive blue catfish population and the effects these voracious eaters may have on the ecosystem.
To support advancement of fisheries science, we manage the Chesapeake Bay Fisheries Research Program. This grant competition supports researchers who explore topics to find answers that fishery managers need. Recent projects have worked to quantify the ecosystem and economic benefits that restored oyster reefs bring to the ecosystem. Other projects have explored summer flounder, black sea bass, and the forage species and habitats they need to thrive.
Our scientists also use data from NOAA buoys and satellites to track water conditions in the Chesapeake Bay and to identify how they may be different from average. That helps them describe what those differences may mean for important species in our Seasonal Summaries.
Habitat Science
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The Chesapeake Bay and its watershed provide habitat for more than 3,600 species of plants and animals. Healthy habitats provide food and shelter for these species, which include fish, crabs, and oysters. The Chesapeake is a diverse ecosystem. Habitats in the Bay include:
The water itself also serves as habitat. Fish and other species are affected by water quality, temperature, and other conditions.
As part of NOAA's efforts to protect and restore a variety of habitats, we conduct science to make restoration as effective and efficient as possible.
We use sonar equipment to gather data and then our experts analyze what is found at the bottom of the Bay and its tributaries. This information can help ensure that oyster reef restoration projects are sited where they can succeed—for example, by making sure the bottom is hard enough so that newly constructed reefs won't sink into the mud. NOAA scientists also track the progress of restored reefs by surveying these areas 3 and 6 years after restoration.
Data from sonar is also helping NOAA's work on Atlantic sturgeon by identifying critical habitat including potential spawning grounds. This is vital for the recovery of this endangered species. Sonar can show where there gravelly bottom sturgeon prefer for egg laying is located, and then resource managers can protect those areas.
NOAA manages a set of observation buoys—the Chesapeake Bay Interpretive Buoy System—that tracks data on water quality as well as meteorological and oceanographic conditions. Data from the buoys is updated every six minutes. It is used by scientists, marine safety organizations, boaters, teachers and students, and others who want to learn more about the Chesapeake.
We also use data from NOAA satellites to understand the effects of water temperature, sediment, and water clarity on habitat.
Oyster Restoration
![Chesapeake-Bay-oyster-restoration.jpg](/s3/dam-migration/chesapeake-bay-oyster-restoration.jpg)
Oysters are an important part of the Chesapeake Bay. They filter and remove excess nutrients like nitrogen from the water and they grow in reefs that provide habitat for fish and crabs. Oyster reefs support not only the ecosystem, but the economy. As a result of disease, overfishing, degraded water quality, and other problems, only about 3 percent of the historic native oyster population remains.
NOAA works with other agencies and organizations to restore oyster reefs in Maryland and Virginia waters of the Chesapeake Bay. NOAA experts lead workgroups that develop and implement restoration work. NOAA scientists conduct sonar surveys and develop habitat analysis to guide projects and monitor progress. And NOAA provides funding to support the hatchery production of baby oysters. Project partners include the Maryland Department of Natural Resources, Virginia Marine Resources Commission, U.S. Army Corps of Engineers, and nonprofit Oyster Recovery Partnership. Universities, local governments, and nonprofits contribute unique skills and resources as well.
The Chesapeake Bay Program, in which NOAA is a partner, has set as a goal to restore oysters to 10 Chesapeake tributaries by 2025. In Maryland, the tributaries are:
- Harris Creek
- Little Choptank River
- Tred Avon River
- St. Mary's River
- Manokin River
In Virginia, the tributaries are:
- Great Wicomico River
- Lafayette River
- Lower York River
- Lynnhaven River
- Piankatank River
Restoration Blueprint
Partners develop a "blueprint" that describes precisely where restoration will happen in each tributary. Each blueprint includes maps generated by NOAA on where the best places for restoration are in that particular tributary. The blueprints also indicate how many oysters will be needed so that the completed project will meet the definition of "restored." They also describe—based on location—what is type of restoration is needed. Some areas might only need to be seeded with "spat-on-shell" baby oysters. Others might need to have reefs constructed and to be seeded with spat on shell. Still others might need to have reefs constructed so that naturally occurring spat have a hard place on which to settle and grow.
Experts monitor each restored reef at 3 and 6 years post-restoration to see how big the reefs are and how many oysters live there. In Maryland, for example, from fall 2015 through fall 2020, they monitored 203 3-year-old reefs and 70 6-year-old reefs. Of these reefs, 96 percent of the 3-year old reefs and 99 percent of the 6-year-old reefs met the minimum criteria for oyster density for success. A full 100 percent of the monitored reefs met the structural success criteria for reef height and footprint. Since the tributaries were chosen in different years, they are all at different stages in their progress toward completion.
All of these large-scale projects are in places that Maryland or Virginia has protected from harvest, giving the oysters the opportunity to grow and thrive. Because oyster larvae float with the currents, larvae produced by a reef in one creek may end up settling in a neighboring creek where harvesting oysters is legal.
Restoration Benefits for Ecosystem and Economy
These restored reef areas serve as a real-life laboratory where scientists can research the benefits they bring to the ecosystem. NOAA scientists and NOAA-funded researchers at academic institutions are exploring the ways restored reefs help the ecosystem and the economy.
Nutrient Removal
Successful oyster reefs are expected to remove about seven times more nitrogen each day than unrestored sand/mud bottoms can. In Harris Creek (Maryland) alone, restored reefs remove nitrogen equivalent to roughly 20,000 bags of garden fertilizer.
Increased Blue Crab Survival
During a study, juvenile crabs had three to four times better chance of surviving predators if they were on a reef than if they were on sandy bottom.
Restored Reefs Provide Economic Boost
Compared to a fished-down starting point, fully mature oyster reefs in one Bay river system would yield a 160 percent increase to the blue crab harvest. It would also create an estimated nearly $23 million increase in annual fishing revenues in the two closest counties. More than 300 (full- and part-time) jobs could result as well.
Restored Reefs, Harvest Reefs Are Visually Different
A video compilation by researchers shows that restored reef areas and areas that are open to oyster harvest can look very different: In restoration reefs, oysters grow vertically, offering lots of habitat area for a range of species. In harvest reefs, the oysters are generally horizontal.
Climate Change
![A man wearing a light blue T-shirt walks through a flooded tree-lined street.](/s3//styles/media_750_x500/s3/dam-migration/750x500-flooded-street-annapolis-md.jpg?itok=xBst9cAn)
Over the past several decades, sea levels and temperatures have risen at rates higher than historical averages. Air temperatures in most locations in the Chesapeake Bay watershed have increased over the last century. These increases range from 0.4 to 2.5 degrees Fahrenheit. Warmer air temperatures lead to warmer water. Over the past 30 years, the average water temperature in the Chesapeake Bay has increased by 1 degree Celsius (1.8 degrees Fahrenheit). And the Chesapeake Bay can expect an additional 1.3 to 5.2 feet in sea level rise over the next century. These and future changes threaten coastal communities, aquatic life, and our ability to restore an already stressed system.
The Chesapeake Bay is particularly vulnerable to these changes because many of its native plants and animals are already at the edge of their temperature range. For example, eelgrass, an underwater grass that currently dominates much of the lower Bay, is at the southernmost edge of its range. As Bay temperatures increase, we are likely to see marked decreases of eelgrass—a critical habitat for fish, crabs, and many other Bay species. But, at least in the Chesapeake Bay, eelgrass can’t simply move farther north. It needs to live in saltier water, like that found in the southern part of the Chesapeake.
Other changes—including variations in salinity, sea level rise, ocean acidification, and storm intensity—could pose challenges to Bay species.
Threats to Coastal Communities
The Chesapeake Bay's coastal communities are a major economic engine for the region. They support commercial and recreational fishing, desirable living areas, and major recreational opportunities. Immediate and potentially life-threatening events such as hurricanes, as well as long-term issues like recurrent tidal flooding, pose real challenges to both safety and the economy.
NOAA provides data and information to help people understand and prepare for climate variability and change across the nation and around the world. We are also looking at climate challenges at a regional level through our partnership in the Chesapeake Bay Program. Through the Climate Resiliency Workgroup, we are working to connect citizens and decision makers with how they can apply climate knowledge to projects, programs, and policies, as well as incorporate climate variability into future restoration and protection efforts. The Chesapeake Bay Program recently released a report about how rising water temperatures could affect species and habitats in the Chesapeake.
We fund research to help fishery managers better understand how to prepare for and adapt to changes in habitat and how those changes will affect important fish species. NOAA buoys monitor environmental conditions, helping us predict changes. And we help educators and students learn more about how a changing climate could affect the Chesapeake Bay
Environmental Literacy
![About a dozen teachers are gathered near a creek in a forest. Three of them crouch down to measure the width of the creek while a woman with a clipboard records their findings.](/s3//styles/media_750_x500/s3/dam-migration/environmental-literacy-ncbo.jpg?itok=xO12xDGR)
Giving area residents the information and tools they need to make good decisions about taking care of the Chesapeake is key to sustaining a healthy Bay. Educating today's students—tomorrow's stewards—is an important part of this effort. We manage programs designed to increase the environmental literacy of students in the Chesapeake Bay watershed.
One of our biggest programs in the area is the Chesapeake Bay-Watershed Education and Training (B-WET) grant program. This program gives support—financial and expertise—to school systems and other organizations that provide education for students and training for teachers. For students, these meaningful watershed educational experiences are often spark a life-long love of the Chesapeake Bay.
NOAA also runs the Environmental Science Training Center to give educators knowledge and tools to deliver up-to-date science information to the next generation of Bay stewards. Workshops are held at the Environmental Science Training Center's home in Oxford, Maryland, and around the Bay watershed. Another learning tool is Chesapeake Exploration, an online platform that gives educators access to courses that advance their knowledge about local science topics and resources.
We are dedicated to helping rising stars in estuarine science and policy grow their skills. Every summer, the NOAA Chesapeake Bay Office hosts several undergraduate and graduate school interns. These experiences give them opportunities to take a deeper dive into an area of their interest. They gain experience working at a NOAA office, while NOAA benefits from the energy and new perspectives these students bring.
NOAA also leads the Chesapeake Bay Program's Education Workgroup, providing expertise and coordination that lead to policies that support environmental literacy throughout the watershed.