Bay Health

Scientists evaluate the Chesapeake Bay’s health by monitoring important habitats, fish and shellfish, and water quality measures. These indicators are useful tools to gauge the overall health of the Bay and the animals that live in it.

The Bay’s health has slowly improved in some areas. However, the ecosystem remains in poor condition. The Bay continues to have polluted water, degraded habitats, and low populations of many fish and shellfish species.

Habitats and Lower Food Web

Overall, the Bay’s habitats and lower food web remain far below what is needed to support thriving populations of underwater life.

• Bay Grasses: In 2012, there were an estimated 48,191 acres of underwater grasses in the Chesapeake Bay achieving 26 percent of the 185,000-acre goal.
• Phytoplankton: A baywide assessment could not be completed in 2012 due to an incomplete data set. In 2011, 56 percent of the Bay's surface waters met the phytoplankton goal.
• Bottom Habitat: In 2012, 45 percent of the Bay and its tidal tributaries met the bottom habitat goal.
• Tidal Wetlands: As of 2005, there were approximately 283,946 acres of tidal wetlands in the Bay region.

Fish and Shellfish

Many of the Bay’s fish and shellfish populations are suffering due to pollution, diseases, overharvesting and lack of food and habitat.

• Blue Crabs: The abundance of spawning-age female blue crabs in the Chesapeake Bay decreased to 97 million in 2012, compared with 194 million in 2011.
• Oysters: According to 2008 data, there are an estimated 3 billion grams of oyster biomass in the Bay and its tidal tributaries.
• Striped Bass: Female striped bass spawning stock biomass measured 111.44 million pounds in 2010.
• American Shad: American shad abundance in the Bay in 2010 was 28 percent of the goal.
• Atlantic Menhaden: Researchers in Maryland caught menhaden in 25 percent of their hauls in 2010.

Water Quality

The Bay’s water quality remains very poor. Too much nutrient and sediment pollution flows to the Bay and its streams, creeks and rivers.

• Dissolved Oxygen: Data from 2009-2011 indicate that 34 percent of the combined open water, deep water and deep channel water volume in the Bay and its tidal tributaries met dissolved oxygen standards during summer.
• Water Clarity: In 2011, 5 percent of the Bay’s tidal waters met the water clarity goal.
• Chlorophyll a: In 2011, 18 percent of the Bay’s tidal waters had chlorophyll a concentrations that achieved the goal.
• Chemical Contaminants: Based on 2010 assessments, 28 percent of analyzed tidal waterways had no impairment for chemical contaminants.