Since its establishment in 1983, the Chesapeake Bay Program has coordinated efforts to restore the Bay. In that time, our focus on science and partnership has enabled us to bring about a wide variety of measurable improvements in the health of the Bay ecosystem. Take a look back at some of the incredible progress we’ve seen over the last 35 years.

Oyster restoration

Bay Program partners completed the largest oyster restoration project in the world in Harris Creek, on Maryland’s Eastern Shore. Now home to 351 acres of oyster reefs, Harris Creek was the first of 10 rivers targeted by the partnership to be restored for oysters.

But that’s not all. The Lafayette River recently became the Bay Program’s second completed river for oyster restoration, and Virginia’s first. The river, whose local oyster industry shuttered in the 1930s, now has a total of 80 acres of reefs.

These restoration milestones would not have been possible without the coordination of multiple partners by the Bay Program, including the National Oceanic and Atmospheric Administration, Army Corps of Engineers, Maryland Department of Natural Resources, Virginia Department of Environmental Quality, Chesapeake Bay Foundation, Elizabeth River Project, Nature Conservancy, Oyster Recovery Partnership and many more.

Pollution reduction

Excess nitrogen, phosphorus and sediment are among the leading causes of the Bay’s poor health. Nitrogen and phosphorus can fuel the growth of algae blooms that lead to low-oxygen “dead zones” in deep waters. Sediment can suffocate shellfish and block sunlight from reaching underwater grasses. Pollution-reducing practices in backyards, in cities and on farms can lower the flow of nitrogen, phosphorus and sediment into waterways.

According to data submitted by Delaware, Maryland, New York, Pennsylvania, Virginia and West Virginia, as well as the District of Columbia, the Chesapeake Bay Program partnership fell short for nitrogen, but exceeded its halfway goal for reducing phosphorus and sediment as measured under the current suite of modeling tools.

Sago pondweed grows in the Severn River Sanctuary in Anne Arundel County, Md., on July 10, 2016. (Photo by Will Parson/Chesapeake Bay Program)

Underwater grasses

Last year, we saw the largest amount of underwater grasses in the Bay in our three decades of collecting data—an estimated 104,843 acres. This surpassed our 2017 restoration target, and along with being the fifth consecutive year of acreage growth, is the first time in modern history that grasses in the Bay have exceeded 100,000 acres. It represents the biggest resurgence of underwater grasses ever recorded, not only in the Chesapeake Bay, but in the entire world.

This resurgence of underwater grasses resulted from pollution reductions and conservation initiatives coordinated by the Chesapeake Bay Program. A recent study, published in the Proceedings of the National Academy of Sciences, analyzed the positive impact of nutrient reductions from the Chesapeake Bay Total Maximum Daily Load (TMDL), or “pollution diet,” and found it to be responsible for the grasses coming back.

Underwater grasses are vital to the health of the Bay. Beds of grasses trap sediment and nutrient pollution, which produces clearer waters. They provide important habitat for critters like blue crabs, who rely on the grasses for protection, and add oxygen to the water, creating a better environment for fish and other species. Underwater grasses are sensitive to pollution but respond quickly to improvements in water quality, making them a good indicator of the overall health of the Bay ecosystem.

Dissolved oxygen

Just like humans, crabs, fish and other underwater animals that live in the Bay need oxygen to survive. Dissolved oxygen is a measurement of how much oxygen is present in the water; as dissolved oxygen levels decrease, it becomes more difficult for animals to get the oxygen they need.

As reported in the University of Maryland Center for Environmental Science’s most recent Chesapeake Bay Report Card, dissolved oxygen levels in many regions of the Bay were frequently in “good condition” (scores of 60 percent or higher) in 2017, with only one region below “moderately good” levels.

Extreme low-oxygen levels can be seen each summer in the Bay’s “dead zone,” which results from a combination of nutrient pollution and warm weather, and can suffocate underwater life. While the size of the dead zone varies year to year, scientists have seen a long-term trend of decline in the duration of the dead zone due to the progress the partnership has made in reducing nutrient pollution.


Organisms that live at the bottom of the Bay and its rivers and streams are known as “benthos.” Benthic communities are made up of worms, clams, oysters, shrimp-like crustaceans and other underwater invertebrates, and they provide food for crabs and bottom-feeding fish.

2017 saw improvement in the condition of benthic communities, as 59 percent of the bottom habitat in the tidal Bay was home to a healthy community of benthic organisms, up from 55 percent in 2016. Scientists attributed this improvement to increases in dissolved oxygen. Many benthic creatures are stuck in one place, like clams and oysters, so they can’t move to avoid polluted waters and are particularly susceptible to stressors. Because of this, the health of benthic communities is a good indicator of overall environmental conditions.

Blue crabs

According to data from the Maryland and Virginia winter dredge survey, an estimated 371 million blue crabs lived in the Bay in 2018. While this marks an 18 percent decrease from the previous year, experts believe the population is healthy, resilient and sustainable. The decrease observed between 2017 and 2018 has been attributed to a drop in the number of adult blue crabs, as the number of juvenile crabs in the Bay rose 34 percent during this time.

The cold weather and ice cover of the past winter took a toll on the population, causing an estimated 35 percent mortality of adult females wintering in Maryland and Virginia waters. Despite that, fisheries managers see evidence that their efforts are working.


The Chesapeake region is home to more than 18 million people, and much of the land in the 64,000-square-mile watershed is privately owned. This makes engaging residents and landowners vital to successfully restoring the Bay. As more individuals and organizations direct their time, talents and resources toward protecting the environment, we will build a larger and more diverse community of stewards to support our conservation goals.


The Bay’s residents are incredibly diverse. When diversity is considered in the planning and implementation of conservation and restoration work, this work is more likely to benefit underrepresented and underserved communities. In the 2014 Watershed Agreement, the Bay Program adopted a goal to reflect that diversity in our workforce, and particularly in our leadership.


To help understand and increase engagement, the Bay Program created the 2017 Citizen Stewardship Index, the first comprehensive survey of stewardship actions and attitudes in the Chesapeake Bay watershed. The index includes information about what behaviors residents are already engaging in to help protect the environment, as well as what behaviors they would be likely to adopt in the future. “The dataset is incredibly powerful,” says Kacey Wetzel, director of programs for outreach and education at the Chesapeake Bay Trust. “It can tell us where we should be doing work, how we should be doing work and who we should be doing work with, so we can do it in more targeted and efficient ways.”

Citizen science

One of the important ways residents are currently getting involved is through citizen science. Residents participate in efforts to record sightings of critters like birds and dolphins, monitor water quality and locate underwater grasses. These efforts help to round out the more large-scale monitoring efforts at the Bay Program and provide important localized information. Recently, the Bay Program signed a memorandum of understanding with the Chesapeake Monitoring Cooperative focused on incorporating more citizen science into the partnership’s work.

None of these environmental success stories would have been possible without the work of our partners and the many dedicated stewards that call our watershed home. Learn more about how you can get involved and help us work toward a healthier Bay.

This article is adapted from one that originally appeared in the Bay Journal.



There are no comments.

Leave a comment:

Time to share! Please leave comments that are respectful and constructive. We do not publish comments that are disrespectful or make false claims.

Thank you!

Your comment has been received. Before it can be published, the comment will be reviewed by our team to ensure it adheres with our rules of engagement.

Back to recent stories