Close to one-quarter of land in the Chesapeake Bay watershed is devoted to agricultural production. Agriculture is essential to all people: farms provide us with food and fiber, natural areas, and aesthetic and environmental benefits. But agriculture is also the single largest source of nutrient and sediment pollution entering the Bay. While conventional tillage, fertilizers and pesticides can be beneficial to crops, their excessive use can pollute rivers and streams, pushing nutrients and sediment into waterways.
Air and water pollution are not separate problems. There is a close link between the health of our air and the health of our water. Nitrogen and chemical contaminants are two types of pollution that harm both the air and the water. Up to one-third of the nitrogen that pollutes the Bay and its rivers comes from the air. Air pollution from a very large geographic area can eventually wind up in the Bay. Sources of air pollution include vehicles, industries, power plants, gas-powered lawn tools, and farm operations.
Bay grasses are plants that grow underwater. They are found in the shallow waters of the Chesapeake Bay and its streams, creeks and rivers. Bay grasses are also known as submerged aquatic vegetation or SAV. Bay grasses are a critical part of the Chesapeake Bay ecosystem. They provide underwater life with food and habitat, absorb nutrients, trap sediment, reduce erosion, and add oxygen to the water. Bay grasses are an excellent measure of the Bay’s overall condition because their health is closely linked with the Bay’s health. Pollution and extreme weather conditions are two factors that hinder bay grass growth. Improving water clarity is the most important part of bay grass restoration because bay grasses need sunlight to grow.
There's nothing more “Chesapeake” than the Bay's signature crustacean, the blue crab. Callinectes (“beautiful swimmer”) sapidus (“savory”), a member of the swimming crab family, is an aggressive, bottom-dwelling predator and one of the most recognizable species in the Bay. The blue crab population is vulnerable to increased harvest pressure, as well as the effects of habitat loss due to poor water quality. Proper management of the crab harvest, as well as water quality improvements and bay grass restoration efforts, will help restore the Bay's blue crab population and maintain this valuable resource into the future.
Chemical contaminants are chemicals or compounds that can potentially harm the heath of humans, wildlife and aquatic life. Toxic chemicals are constantly entering the Chesapeake Bay and its tributaries via wastewater, agriculture, stormwater and air pollution. While chemicals such as DDT and PCBs have been banned from production for years, many chemical contaminants are still widely used or persist in the environment.
Like countless other parts of the world, the Chesapeake region has begun to feel the effects of a changing climate. As warmer temperatures and higher sea levels are noted in the region, Bay scientists are working to understand the possible effects of these changes on the Bay and its watershed, including how they may affect Bay restoration efforts already in progress.
As more people move into the Bay watershed, development of new homes, roads and businesses continues. We are choosing to move away from city centers and live in bigger houses on larger lots, causing forests, farms and other valuable lands to be transformed into subdivisions, shopping centers and parking lots—severely impacting the health of our streams, rivers and the Bay.
One of the most important parts of Chesapeake Bay restoration is teaching the public about the Bay and its local waterways. Bay Program partners work to educate and engage residents through formal curriculum-based learned and informal programs at parks and other sites.
Fish consumption advisories are public health notices that warn people about possible health risks from eating fish and shellfish from certain waterways. Fish consumption advisories are usually issued because of pollution from chemical contaminants such as mercury and PCBs. Each state and the District of Columbia issues fish consumption advisories for their local waterways, including the Chesapeake Bay.
Forest buffers, or the trees, shrubs and other plants that grow next to streams and rivers, are critical to the health of the Chesapeake Bay. Forest buffers prevent pollution from entering waterways, stabilize stream banks, provide food and habitat to wildlife and keep streams cool during hot weather. Chesapeake Bay Program partners are working to restore 900 miles of forest buffers per year until 70 percent of all stream banks and shorelines in the watershed are buffered.
Forests are one of the most beneficial land use for protecting clean water. Every acre of forestland converted to another type of land use allows more nutrients to flow into the Bay and its tributaries. Historic and current human-related influences have significantly changed the Chesapeake's forests. Retaining and expanding forests is a critical, cost-effective way to reduce pollution and help restore the Bay.
Drops of rain that fall on the land do not always wash into the Bay or one of its tributaries right away. Instead, precipitation can seep through the soil and into groundwater.
Invasive species are animals and plants that are not native to their current habitat and have a negative effect on the ecosystem they invade. Invasive species negatively affect an ecosystem by encroaching on native species' food and/or habitat.
Atlantic menhaden is an important fish species because it forms a critical link between the upper and lower levels of the Bay food web. While menhaden populations along the Atlantic coast appear to be healthy, there is concern about low regional abundance (also referred to as “localized depletion”), specifically in Chesapeake Bay. To prevent a possible future decline of this keystone species, a cap has been placed on the amount of menhaden that can be harvested from the Bay. In addition, scientists are currently studying the effects of predation and fishing on menhaden as part of a multi-species model of the coast-wide Atlantic menhaden stock.
Nutrients are chemicals that plants and animals need to grow and survive. When too many nutrients make their way into local rivers, streams and the Bay, they can create conditions that are harmful for blue crabs, bay grasses and other underwater life. Excess amounts of nitrogen and phosphorus, two types of nutrients, are the main cause of the Bay's poor health.
The eastern oyster is one of the most famous and recognizable aquatic species in the Chesapeake Bay. For more than a century, oysters made up one of the Bay's most valuable commercial fisheries. The interaction of over-harvesting, disease, sedimentation and poor water quality has since caused a severe decline in their numbers throughout the Chesapeake.
With its strong economy, diverse communities and numerous natural and historical attractions, it's no wonder that more than 17 million people call the Chesapeake Bay watershed home. However, the current rate of population growth has raised concerns about whether the region can sustain not only humans, but all of the animals and plants that live here.
Within the Chesapeake Bay watershed, five major rivers — the Susquehanna, Potomac, Rappahannock, York and James — provide almost 90 percent of the fresh water to the Bay. These and other rivers, along with the hundreds of thousands of creeks and streams that feed them, provide vital habitat for many aquatic species. The streams and rivers that flow into the Bay are also called tributaries.
Sediment is made up of loose particles of sand, silt and clay. It is a natural part of the Chesapeake Bay, created by the weathering of rocks and soil. In excess amounts, sediment can cloud the waters of the Bay and its tributaries, harming underwater grasses, fish and shellfish.
American shad is the most well-known of the Chesapeake Bay’s shad and river herring. Other species include hickory shad, alewife and blueback herring. These fish are collectively known as “alosines.” Shad form an important link in the Chesapeake Bay food web. They feed on plankton, and in turn are eaten by larger predators. American shad once supported the most valuable finfish fishery in the Chesapeake Bay. Shad populations are depleted due to pollution, historic overfishing, and dams that block access to the fish’s freshwater spawning grounds. Commercial shad harvest has been banned for decades throughout the Chesapeake Bay and its rivers. Although Bay Program partners are working to remove dams, install fish passageways and stock rivers with hatchery-reared fish, shad populations remain very low due to a variety of factors.
Do you ever think about what happens to a drop of rain that falls onto the ground? It may land on a tree and evaporate; it may land on a farm field and be absorbed into the soil; or it may land on a rooftop, driveway or road and travel down the street into a stream or storm drain. Any precipitation in an urban or suburban area that does not evaporate or soak into the ground, but instead pools and travels downhill, is considered stormwater. Stormwater is also referred to as urban stormwater, runoff and polluted runoff. Increased development across the Bay watershed has made stormwater runoff the fastest growing source of pollution to the Bay and its rivers.
Striped bass — also known as rockfish or stripers — has been one of the most sought-after commercial and recreational fish in the Chesapeake Bay since colonial times. After bouncing back from a severe decline in the 1970s and 1980s, the striped bass population is now at its highest level in decades. However, scientists are uncertain about the health of the species because of a high prevalence of disease and possible lack of prey.
Hundreds of wastewater treatment facilities throughout the Chesapeake Bay watershed are being upgraded with advanced technology to reduce the amount of nutrients that are discharged into the Bay's tributaries. Wastewater treatment plant upgrades account for a large portion of overall estimated nutrient reductions to date, and Bay jurisdictions are relying on additional reductions from wastewater to achieve about 15 percent of total overall nutrient reduction goals.
Rain, wind and temperature can have wide-ranging effects on the Bay's habitat, water quality and fish and shellfish populations. All plants and animals can adapt to periodic changes in environmental conditions. However, scientists cannot predict with certainty how the diverse Bay ecosystem will react to prolonged periods of extreme weather conditions.
Wetlands are transitional areas between land and water. While some wetlands are noticeably wet, others do not always have visible water. An area is defined as a wetland based on its soils and vegetation. All wetlands are dominated by hydrophytes, which are plants that are adapted for life in wet soils. Wetlands also have hydric soils, which are soils that are periodically saturated or flooded.