Learn the Issues

Learn about many of the complex problems facing the Chesapeake Bay: from the excess nutrients and sediment that pollute our waters, to the invasive species that crowd out native plants and animals, to a changing climate that is already affecting our land, air and water.


Farms provide us with food and fiber, natural areas and environmental benefits. But agriculture is also the largest source of nutrient and sediment pollution entering the Bay.

Air Pollution

Pollution emitted by cars, trucks, power plants and other sources doesn’t just cloud the air we breathe—it falls back onto the earth’s surface, where it can wind up in our waterways.

Blue Crabs

The Bay’s signature crustacean supports important commercial and recreational fisheries. But pollution, habitat loss and harvest pressures threaten blue crab abundance.

Chemical Contaminants

Almost three-quarters of the Bay’s tidal waters are impaired by pesticides, pharmaceuticals, metals and other chemicals, which can harm the health of both humans and wildlife.

Climate Change

Some effects of climate change—rising seas, warming water temperatures and prolonged periods of extreme weather—are already being observed in the Bay region.

Conowingo Dam

The reservoir behind Conowingo Dam has long captured sediment flowing downstream, but recent studies have drawn attention to its changing effectiveness as a “pollution gate.”


As more people move into the Chesapeake Bay region, development has turned forests, farms and other landscapes into subdivisions, shopping centers and parking lots.

Forest Buffers

Streamside trees and shrubs prevent pollution from entering waterways, stabilize stream banks, provide food and habitat to wildlife and keep streams cool during hot weather.


Forests are critical to the health of the Chesapeake Bay—but human activities have altered the region’s forests, reducing tree cover and fragmenting forests that still exist.


Drops of rain or snow that fall onto the land can seep through the soil and into groundwater, which can become contaminated when pollutants on land seep underground.

Invasive Species

Invasive species—plants or animals that have been introduced to their current habitat—can cause harm when they establish themselves at the expense of native plants and animals.


These small fish form an important link in the Chesapeake Bay food web, which is why fisheries managers have placed a cap on the amount of menhaden that can be harvested from the Bay.


Plants and animals need nutrients to survive. But when too many nutrients enter waterways, they fuel the growth of algae blooms and create conditions that are harmful to underwater life.


This iconic bivalve helps to improve water quality and provides food and habitat to other animals. But over-harvesting, disease and habitat loss have led to a severe drop in population.

Population Growth

The Chesapeake Bay region’s rapid rate of population growth has raised concerns over whether the watershed can continue to sustain the plants, animals and people that live here.

Rivers and Streams

Hundreds of thousands of creeks, streams and rivers flow through the Chesapeake Bay region, sending fresh water to the Bay and providing habitat to aquatic plants and animals.


Sand, silt and clay are a natural part of the Chesapeake Bay. But in excess amounts, sediment can cloud the waters of the Bay and its tributaries, harming underwater life.


Once the most valuable finfish fishery in the region, pollution, historic overfishing and the construction of dams that block migration have lowered shad populations.

Stormwater Runoff

When precipitation falls on roads, streets, rooftops and sidewalks, it can push harmful pollutants like fertilizer, pet waste, chemical contaminants and litter into the nearest waterway.

Striped Bass

Also known as rockfish, striped bass are recovering from a severe decline in the 1970s and 80s. But disease and lack of prey keep scientists uncertain about the long-term health of the species.

Underwater Grasses

Underwater grasses grow in the shallow waters of the Bay and its streams. They provide food and habitat to wildlife, add oxygen to the water and trap sediment and nutrient pollution.


Hundreds of wastewater treatment facilities throughout the Chesapeake Bay region are being upgraded to reduce the amount of nutrients flowing into local waterways.


Wetlands are critical in supporting the healthy waters and diverse wildlife of the region. But development, invasive species and sea level rise threaten these important areas.