Track Our Progress - Chesapeake Bay Program

The Chesapeake Bay Program tracks more than 30 environmental indicators to gauge the success of our efforts to protect and restore the Bay, its tributaries and the lands that surround them. Some indicators—like blue crab abundance, water quality and forest cover—track aspects of watershed health. Others—like public access, protected land and open fish passage—track our restoration and protection work.

What Guides Us

Over our long history, the Chesapeake Bay Program has developed a series of written agreements and science-based goals to guide our work. Today, we work under the Chesapeake Bay Watershed Agreement: an inclusive, goal-oriented document signed on June 16, 2014, by representatives from the entire watershed. Learn more about this agreement and those we have followed in the past.

Tracking Tools

The Chesapeake Bay Program uses a suite of tools to track our work toward restoring the Chesapeake Bay. These tools are part of ChesapeakeStat: a framework that explains how we are governed, how we work and how we can be held accountable for what we do. Learn more about ChesapeakeProgress, ChesapeakeDecisions and ChesapeakeData.

Indicators: A-Z

This list includes the environmental indicators the Chesapeake Bay Program currently tracks to gauge the success of our efforts to protect and restore the Bay, its tributaries and the lands that surround them.

American Shad Abundance

Shad Abundance (2015) American shad (Alosa sapidissima) form an important link in the Chesapeake Bay’s food web. The return of the migratory fish from the ocean to freshwater rivers each spring brings food to the Bay in the form of protein-rich eggs, adult shad that can be captured during the spawn and a new generation of shad that can offer forage to striped bass, bluefish and other species when they return to the sea. But pollution, historic overfishing and the construction of dams that block the migratory fish from reaching their upstream spawning grounds have critically lowered shad populations. Shad recovery is progressing, but can be hampered by natural predation and commercial bycatch. Commercial harvest is closed across most of the region and our partners are working to remove dams and restock rivers with hatchery-raised fish. (Read More)

Atlantic Menhaden Abundance

Atlantic menhaden are critical to the Chesapeake Bay ecosystem. The fish filters pollutants out of the water and is a source of food for striped bass and other species. The Bay provides a nursery to young menhaden, supporting the juveniles that will join the Atlantic coast’s adult menhaden stock. Menhaden are harvested commercially for bait and for an industry that uses them to produce fishmeal and fish oil. According to the Atlantic States Marine Fisheries Commission’s (ASMFC) 2014 Benchmark Stock Assessment, the menhaden population along the North Atlantic coast is not overfished and overfishing is not occurring. (Read More)

Atlantic Menhaden Fishery Management

Bay Watershed Forest Cover

Forests are crucial to the health of the Chesapeake Bay. Forests protect clean air and water, provide habitat to wildlife, store carbon, control floods and support the region’s economy. But human activities have altered the watershed’s forests, reducing tree cover and fragmenting forests that still exist. When forests are destroyed by development, their ecological services and economic benefits are lost. Conserving and expanding forest cover is a critical, cost-effective way to reduce pollution and restore the Bay. (Read More)

Blue Crab Abundance (Spawning-Age Females)

Perhaps no species is more closely associated with the Chesapeake Bay than the blue crab. Blue crabs support commercial and recreational fisheries across the region, but poor water quality, habitat loss, harvest pressure and natural predation affect their continued health. Blue crab population levels inform how harvest regulations should or shouldn’t change if we are to maintain a sustainable blue crab stock. (Read More)

Blue Crab Fishery Management

Chemical Contaminants

Chemical Contaminants (2012) Pesticides, pharmaceuticals, polychlorinated biphenyls (PCBs) and other chemical contaminants can be found in the sediment and tissues of fish in the Chesapeake Bay. These contaminants—also known as toxics—can harm human health and affect the survival, growth and reproduction of fish and wildlife. Toxics enter the food web when small, bottom-dwelling organisms take them up while feeding or through direct skin contact. Contaminated organisms pass toxics on to the larger fish, birds and people that eat them. By analyzing the tissues of certain fish species, scientists can estimate the overall presence of toxics in the ecosystem. While toxics are often seen as a local problem occurring in “hot spots” or “regions of concern” (like Baltimore Harbor or the Anacostia and Elizabeth rivers), this indicator shows that chemical contamination can pose a problem outside (Read More)

Chesapeake Bay Watershed Population

Each person that lives in the Chesapeake Bay watershed affects the Bay ecosystem. We consume natural resources; we pollute the air, land and water; and we alter forests and wetlands to fit our needs. The health of our rivers and streams is directly tied to population growth, and the decline of the Bay is correlated with the rise in the number of people that live in its watershed. (Read More)

Dissolved Oxygen (Volume Assessment)

Like animals on land, living creatures in the Chesapeake Bay need oxygen to survive. In the water, oxygen is present in dissolved form. Without adequate concentrations of dissolved oxygen, the Bay’s ability to support aquatic life is compromised. Dissolved oxygen concentrations are an important indicator of nutrient pollution. This is because low dissolved oxygen levels are often the result of nutrient-fueled algae blooms. When algae blooms die and undergo bacterial decomposition, these bacteria use up oxygen in the water, leaving little for fish and shellfish and creating what are known as “dead zones.” Increased nutrient pollution leads to larger algae blooms, which in turn create more dead zones. Over time, large-scale reductions in the amount of nutrients flowing into the Bay will help improve low-oxygen conditions. (Read More)

Health of Freshwater Streams in the Chesapeake Bay Watershed

Average 2000-2010 Stream Health in the Chesapeake Bay Sub-watersheds An effective way to measure the health of freshwater streams and rivers is to study the many tiny creatures that live in these waters. The abundance and diversity of snails, mussels, insects and other bottom-dwelling organisms – known as benthic macroinvertebrates – are good indicators of the health of streams because these creatures can’t move very far and they respond in certain predictable ways to pollution and environmental stresses. A healthy Bay watershed would have a majority of streams ranked as fair, good or excellent. Some generalizations about the health of the watershed’s streams can be made: Streams tend to be in very poor to fair condition around large urban areas, such as metropolitan Washington, D.C. Streams in heavily farmed or mined areas are also often in very poor to fair condition. These (Read More)

Nitrogen in Rivers Entering Chesapeake Bay: Long-Term Flow-Adjusted Concentration Trends

Excess nitrogen is among the leading causes of the Chesapeake Bay’s poor health. But nitrogen concentrations are highly variable, depending on the amount of water flowing in streams and rivers across the watershed. For this reason, scientists calculate flow-adjusted concentration trends to determine whether nitrogen concentrations have changed over time. By examining data that is presented independently of the effects of variations in stream flow, resource managers can better evaluate the changes in stream health that have and could continue to result from pollution-reducing practices or other activities in the watershed. (Read More)

Nitrogen in Rivers Entering Chesapeake Bay: Short-Term Flow-Adjusted Concentration Trends

Nitrogen Loads and River Flow to the Chesapeake Bay

Each day, billions of gallons of fresh water flow from rivers and streams into the Chesapeake Bay. The amount of water that flows out of these tributaries has a direct impact on pollution: as snowmelt or rainfall increase river flow, more pollution is pushed into the estuary. In other words, precipitation and river flow are two factors that affect pollution loads and water quality. Nutrient pollution is one of the leading causes of the Bay’s poor health. When nitrogen and phosphorus enter rivers, streams and the Bay, they can fuel the growth of algae blooms that lead to low-oxygen “dead zones” harmful to fish, shellfish and other aquatic life. (Read More)

Nitrogen Yields Measured in Watershed Streams and Rivers

Total Nitrogen Yields Measured in Watershed Streams and Rivers, Mean 2008-2012 Stream quality is associated with lower nutrient loads; therefore, the goal for short-term yields indicator is to observe low nitrogen yields at most monitoring sites in the watershed. (Read More)

Phosphorus in Rivers Entering Chesapeake Bay: Long-Term Flow-Adjusted Concentration Trends

Excess phosphorus is among the leading causes of the Chesapeake Bay’s poor health. But phosphorus concentrations are highly variable, depending on the amount of water flowing in streams and rivers across the watershed. For this reason, scientists calculate flow-adjusted concentration trends to determine whether phosphorus concentrations have changed over time. By examining data that is presented independently of the effects of variations in stream flow, resource managers can better evaluate the changes in stream health that have and could continue to result from pollution-reducing practices or other activities in the watershed. (Read More)

Phosphorus in Rivers Entering Chesapeake Bay: Short-Term Flow-Adjusted Concentration Trends

Phosphorus Loads and River Flow to the Chesapeake Bay

Phosphorus Yields Measured in Watershed Streams and Rivers

Total Phosphorus Yields Measured in Watershed Streams and Rivers, Mean 2008-2012 Stream quality is associated with lower nutrient loads; therefore, the goal for short-term yields indicator is to observe low phosphorus yields at most monitoring sites in the watershed. (Read More)

Planting Forest Buffers

Forest buffers, or the trees, shrubs and other plants that grow along streams and rivers, are critical to the health of the Chesapeake Bay. Forest buffers prevent pollution from entering waterways, stabilize stream banks, provide critters with food and habitat, and keep streams cool during hot weather (to the benefit of sensitive aquatic species). (Read More)

Protected Lands

Chesapeake Bay Program partners have identified millions of acres of lands with high conservation value. These lands protect water quality, sustain fish and wildlife, maintain working farms and forests, preserve our history, and provide opportunities for outdoor recreation. But population growth, development and climate change increase pressure on some of the most valuable lands in the watershed. Land is a finite and fragile resource. For decades, our partners have permanently protected from development lands that have cultural, historical, ecological or agricultural value. Partners have purchased properties, accepted donations, arranged for easements and purchased development rights. Conserving land relies on public support. Reporting on the status of land protection in the watershed can help generate that support and provide transparency related to these efforts. (Read More)

Public Access

Public access to open space and waterways can improve public health and quality of life. People rely on outdoor places to exercise, relax and recharge their spirits. Time outdoors can strengthen family bonds and nurture active, creative children. At the same time, access to the Chesapeake Bay and its tributaries can build personal connections with the places that have shaped life in the region for centuries. This can boost tourism economies and create citizen stewards who care for local resources and engage in conservation efforts. As development continues across the region, demand for places that allow the public to reach the water will remain high. (Read More)

Reducing Nitrogen Pollution

Excess nitrogen is one of the leading causes of the Chesapeake Bay’s poor health. When nitrogen and phosphorus enter rivers, streams and the Bay, they fuel the growth of algae blooms that lead to low-oxygen “dead zones” that are harmful to fish, shellfish and other aquatic life. In general, nitrogen and phosphorus reach the Bay through three sources: wastewater treatment plants; urban, suburban and agricultural runoff; and air pollution. The Total Maximum Daily Load (TMDL) limits the amount of nutrients that can enter the Bay if it is to achieve water quality standards. (Read More)

Reducing Phosphorus Pollution

Excess phosphorus is one of the leading causes of the Chesapeake Bay’s poor health. When nitrogen and phosphorus enter rivers, streams and the Bay, they fuel the growth of algae blooms that lead to low-oxygen “dead zones” that are harmful to fish, shellfish and other aquatic life. In general, nitrogen and phosphorus reach the Bay through three sources: wastewater treatment plants; urban, suburban and agricultural runoff; and air pollution. The Total Maximum Daily Load (TMDL) limits the amount of nutrients that can enter the Bay if it is to achieve water quality standards. (Read More)

Reducing Sediment Pollution

Excess sediment is one of the leading causes of the Chesapeake Bay’s poor health. While loose particles of sand, silt and clay are natural parts of the environment, too much sediment can cloud the waters of the Bay and its tributaries, harming underwater grasses, fish and shellfish. Sediment enters the Bay when land, stream banks and shorelines erode. Erosion increases when land is cleared for agriculture and development. The Total Maximum Daily Load (TMDL) limits the amount of sediment that can enter the Bay if it is to achieve water quality standards. (Read More)

Reopening Fish Passage

The Chesapeake Bay watershed is home to several fish species that move between freshwater rivers and the saltier waters of the ocean to spawn. Dams, culverts and other structures can block these migratory fish from reaching their spawning grounds and reduce the amount of habitat available to local fish. Removing dams or installing lifts, ladders, or passageways can reopen river habitat and allow fish like alewife or American shad to swim farther upstream. In restoring the natural flow of waterways, these projects can also reduce the harmful build-up of sediment. (Read More)

Restoring Oyster Reefs

Restoring oyster reefs in the Chesapeake Bay is a primary part of our strategy to increase native oyster populations and the benefits these reefs provide to fish and shellfish. To rebuild reefs, both oyster shell and alternative materials for oysters to settle and grow upon (like granite, fossil shell or crushed concrete) are placed on hard-bottom areas in select tributaries. Hatchery-raised oyster larvae, called spat, are planted on both natural and man-made reefs. Many of these rebuilt reefs are designated as oyster sanctuaries and protected from harvest. Restoring reefs has the potential to increase populations of spawning adult oysters and, in turn, larval production. Oyster reefs also provide important ecosystem services to the Bay, as the reefs offer habitat to invertebrates and fish and filter-feeding oysters improve water quality. (Read More)

Restoring Wetlands on Agricultural Lands

Healthy wetlands are vital to a healthy Chesapeake Bay. Located where land meets water, wetlands trap polluted runoff and slow of the flow of nutrients, sediment and chemical contaminants into rivers, streams and the Bay. By soaking up stormwater and dampening storm surges, wetlands slow the erosion of shorelines and protect properties from floods. Wetlands also provide critical habitat for fish, birds, mammals and invertebrates, and support recreational fishing and hunting across the watershed. Land purchases and conservation easements can protect wetland habitat. The removal of invasive species—like phragmites, purple loosestrife or nutria—can help rehabilitate degraded wetlands. (Read More)

River Flow Into Chesapeake Bay

Sediment in Rivers Entering Chesapeake Bay: Long-Term Flow-Adjusted Concentration Trends

Excess sediment is among the leading causes of the Chesapeake Bay’s poor health. But sediment concentrations are highly variable, depending on the amount of water flowing in streams and rivers across the watershed. For this reason, scientists calculate flow-adjusted concentration trends to determine whether sediment concentrations have changed over time. By examining data that is presented independently of the effects of variations in stream flow, resource managers can better evaluate the changes in stream health that have and could continue to result from pollution-reducing practices or other activities in the watershed. (Read More)

Sediment in Rivers Entering Chesapeake Bay: Short-Term Flow-Adjusted Concentration Trends

Sediment Loads and River Flow to the Chesapeake Bay

Each day, billions of gallons of fresh water flow from rivers and streams into the Chesapeake Bay. The amount of water that flows out of these tributaries has a direct impact on pollution: as snowmelt or rainfall increase river flow, more pollution is pushed into the estuary. In other words, precipitation and river flow are two factors that affect pollution loads and water quality. Sediment pollution is one of the leading causes of the Bay’s poor health. While loose particles of sand, silt and clay are natural parts of the environment, too much sediment can cloud the water and harm underwater grasses, fish and shellfish. (Read More)

Sediment Yields Measured in Watershed Streams and Rivers

Sediment Yields Measured in Watershed Streams and Rivers, Mean 2008-2012 Stream quality is associated with lower sediment loads; therefore, the goal for short-term yields indicator is to observe low sediment yields at most monitoring sites in the watershed. (Read More)

Striped Bass Abundance

The Chesapeake Bay is one of the most important striped bass spawning and nursery habitats on the East Coast, supporting valuable commercial and recreational fisheries. While the striped bass population experienced severe declines in the 1970s and 1980s, the biomass of adult female striped bass along the Atlantic Coast—which is tracked as an indicator of coast-wide striped bass abundance—has remained above the threshold since 1995. Multi-state fishing moratoria in the late 1980s and commercial harvest quotas and recreational harvest limits set in the 1990s were critical to rebuilding the striped bass stock. In order to determine the status of striped bass along the Atlantic Coast, the Atlantic States Marine Fisheries Commission (ASMFC) also tracks fishing mortality—or the rate of removal due to fishing—against a target and threshold. Fishing mortality estimates include harvest, discard (Read More)

Striped Bass Fishery Management

Striped Bass Juvenile Abundance Index

The Chesapeake Bay is one of the most important striped bass breeding habitats on the East Coast, supporting valuable commercial and recreational fisheries. To monitor the reproductive success of striped bass, scientists take annual seine net samples in noted spawning areas, which include the Choptank, Potomac and Nanticoke rivers in Maryland and the Rappahannock, York and James rivers in Virginia. The average number of young-of-the-year striped bass—or rockfish that are less than one year old—in each seine haul is known as the juvenile abundance index. The abundance indices developed in Maryland and Virginia document the annual variation in striped bass year classes and help scientists evaluate the health of the striped bass stock. These indices also serve as early indicators of future adult fish abundance, helping managers predict the amount of adult fish that will be (Read More)

Tidal Wetlands Abundance

Healthy wetlands are vital to a healthy Chesapeake Bay. Located where land meets water, wetlands trap polluted runoff and slow of the flow of nutrients, sediment and chemical contaminants into rivers, streams and the Bay. By soaking up stormwater and dampening storm surges, wetlands slow the erosion of shorelines and protect properties from floods. Wetlands also provide critical habitat for fish, birds, mammals and invertebrates, and support recreational fishing and hunting across the watershed. Shoreline development, sea level rise and invasive species pose the biggest threats to tidal wetlands. Development along beaches and shorelines blocks the formation of wetland habitat and sends excess sediment into the Bay. Sea level rise floods wetlands with saltwater, destroying plants faster than they can populate higher ground. And invasive plants and animals can crowd out native species or damage wetland habitat. Chesapeake Bay Program (Read More)

Underwater Bay Grass Abundance (Baywide)

Restoring underwater grasses to the rivers, streams and shallow waters of the Chesapeake Bay will dramatically improve the Bay ecosystem. Grass beds provide food and shelter to fish, crustaceans and other species, add oxygen to the water, absorb nutrient pollution, reduce shoreline erosion and help suspended particles of sediment settle to the bottom. Underwater grasses—also known as submerged aquatic vegetation or SAV—are sensitive to pollution but quick to respond to improvements in water quality. This means their abundance is a good indicator of Bay health. As pollution declines and water clarity improves, scientists expect underwater grass beds to expand. (Read More)

Wastewater

The Bay cannot be restored without water that is clean, clear and rich in oxygen. Currently, the Bay and its rivers receive too much nitrogen, phosphorus and sediment for the ecosystem to remain healthy. Wastewater treatment plant discharges are one of the primary sources of these pollutants. (Read More)

Water Quality Standards Achievement

The Chesapeake Bay and its tidal tributaries can be divided into 92 segments. Each of these segments contains up to five “designated uses,” included deep channel; deep water; open water; shallow water; and migratory fish, spawning and nursery. In all, the Bay and its tidal tributaries contain 291 designated uses. Each of these designated uses—also known as aquatic habitats—has its own set of criteria for dissolved oxygen, water clarity/underwater grasses and chlorophyll a designed to protect those uses. If the Bay and its tidal tributaries are to function as a healthy ecosystem, all water quality standards must be met. (Read More)

Water Quality Standards Achievement for Chlorophyll a

Excess nutrients and sediment are among the leading causes of the Chesapeake Bay’s poor health. Both can impact the clarity of water and the amount of algae and oxygen it contains. This indicator measures the achievement of water quality standards for chlorophyll a in the Bay. Water quality standards for the Bay were developed in 2003 by the U.S. Environmental Protection Agency (EPA). Within these standards, five aquatic habitats—also called “designated uses”—were identified, each with its own criteria for dissolved oxygen, water clarity/underwater grasses and chlorophyll a. If the Bay and its tidal tributaries are to function as a healthy ecosystem, all designated uses must meet all clean water criteria. (Read More)

Water Quality Standards Achievement for Dissolved Oxygen (Surface Area Assessment)

Excess nutrients and sediment are among the leading causes of the Chesapeake Bay’s poor health. Both can impact the clarity of water and the amount of algae and oxygen it contains. This indicator measures the achievement of water quality standards in the Bay for the latter environmental factor, known as dissolved oxygen. Like humans, all of the Bay’s living creatures need oxygen to survive. But the amount of oxygen an animal needs can vary depending on the animal’s size and habitat. Water quality standards for the Bay were developed in 2003 by the U.S. Environmental Protection Agency (EPA). Within these standards, five aquatic habitats—also called “designated uses”—were identified, each with its own criteria for dissolved oxygen, water clarity/underwater grasses and chlorophyll a. If the Bay and (Read More)

Water Quality Standards Achievement for Water Clarity/Underwater Bay Grasses

Excess nutrients and sediment are among the leading causes of the Chesapeake Bay’s poor health. Both can impact the clarity of water and the amount of algae and oxygen it contains. This indicator measures the achievement of water quality standards for water clarity in the Bay. Water quality standards for the Bay were developed in 2003 by the U.S. Environmental Protection Agency (EPA). Within these standards, five aquatic habitats—also called “designated uses”—were identified, each with its own criteria for dissolved oxygen, water clarity/underwater grasses and chlorophyll a. If the Bay and its tidal tributaries are to function as a healthy ecosystem, all designated uses must meet all clean water criteria. (Read More)

Indicators: Archives

This list includes the environmental indicators the Chesapeake Bay Program formerly tracked to gauge the success of our efforts to protect the Bay, its tributaries and the lands that surround them. These indicators are no longer tracked for various reasons. In some cases, the related goal was met. In other cases, the indicator or its tracking method was revised.

Chesapeake Bay Gateways Designated

For people to deeply value the Bay and the thousands of streams, creeks and rivers that flow into it, they need access to wildlife and the outdoors. Public access areas allow people to enjoy activities such as fishing, swimming, kayaking, hiking and picnicking. Access to natural areas helps people create a personal connection with the Bay watershed and builds support for restoration efforts. (Read More)

Developing Watershed Management Plans

Protecting local watersheds is a complicated and challenging task. Watershed management plans are strategic guides that help local communities protect and restore streams, forest buffers, wetlands, parks and other natural areas. Watershed plans preserve not only ecological health, but also the quality of life in communities. (Read More)

Education and Interpretation

The long-term health of the environment will depend on the public’s interest in and ability to protect the natural world. Research has shown that an individual’s sense of environmental stewardship can increase alongside experiences with nature. By promoting environmental education at elementary, middle and high schools and by incorporating Meaningful Watershed Educational Experiences (MWEEs) into formal education, Chesapeake Bay Program partners foster environmental stewardship from an early age. (Read More)

Native Oyster Health

Oysters are a valuable species because they improve water quality, provide habitat for aquatic life and contribute to the region’s economy. Oysters filter water as they feed, which increases water clarity. It is estimated that at their historic population peak, oysters filtered all of the Bay’s water in less than one week. It takes about one year for the current population to do so. Oysters have also constituted one of the Bay’s most valuable commercial fisheries for more than a century. Pollution, historic overharvesting, and the diseases MSX and Dermo have caused the oyster population to decline severely. (Read More)