Researchers from the Chesapeake Bay Program, University of Maryland Center for Environmental Science, University of Michigan, and U.S. Geological Survey have predicted that the Bay’s summertime “dead zone” will be about 13% smaller in 2022 than the average size of the dead zone recorded between 1985 and 2021.
According to the state-federal Chesapeake Bay Program, which leads the restoration effort, this is due to less water entering the Bay from its rivers this spring, as well as a decrease in nutrient pollution from some areas of the Bay’s six-state watershed.
The Bay’s dead zone is a deepwater area with low levels of dissolved oxygen that are hostile to marine life, including fish, blue crabs, and oysters. The dead zone is mostly caused by nutrient pollution from human wastewater, animal manure, and fertilizer.
The amount of pollution reaching the Bay each year varies and is based on the amount of rainfall, which flushes nutrients and sediment into rivers that flow into the Bay. The load is also impacted by the number and effectiveness of conservation practices that reduce and manage those pollutants.
The 2021 dead zone was approximately 14% lower than the long-term average.
An assessment of the 2022 dead zone will be available this fall.