The Chesapeake Bay’s dead zone, a low-oxygen area that can smother underwater life, was about average in size in 2024, according to data released today.
The results come during a crossroads for the Chesapeake Bay, as leaders from across the region plan to meet in December to chart a course for Bay cleanup beyond a long-anticipated 2025 deadline.
The dead zone forms every year in parts of the Bay and its tidal rivers during warmer months. It is defined by areas where oxygen levels are so low that the water cannot support fish, blue crabs, oysters, and other aquatic life. This is caused by explosions of algae growth, called algal blooms, which are fed by nitrogen and phosphorus pollution and thrive in warm temperatures. The algae cloud water and suck up oxygen as they decompose.
Dead zone fluctuations from year to year are often connected to weather. Heavy rainfall can wash more pollution into the Bay in the form of runoff. High summer air and water temperatures, driven by climate change, and light winds can also induce the right conditions for excessive algae growth. Work to prevent excess nitrogen and phosphorus pollution is the best way to limit the size of the dead zone.
Despite progress in recent years, states in the Bay watershed will not meet pollution-reduction commitments by a 2025 deadline. The region’s governors, and other state, local, and federal leaders, must confront this challenge at the Chesapeake Executive Council meeting on Dec. 10 in Annapolis, Maryland.
The Maryland Department of Natural Resources and Virginia Institute of Marine Science monitor the size of the dead zone and the EPA’s Chesapeake Bay Program releases this annual report. In 2023, results showed the smallest dead zone since monitoring began in 1985.
CBF Vice President for Environmental Protection and Restoration Alison Prost issued the following statement.
“The only way to shrink the Chesapeake Bay’s dead zone is by working across state lines. Too much pollution from six states and Washington, D.C., still flows into the Bay and fuels this degrading phenomenon that chokes underwater life. Thankfully, Bay restoration science continues to evolve highlighting ways we can be more efficient and targeted in our pollution reduction efforts.
“For decades, the Bay restoration partnership has brought federal, state, and local efforts together around common goals for a healthier Chesapeake Bay. As the 2025 deadline approaches, we’re at a crossroads.
“At the Chesapeake Executive Council meeting this December we must see leadership, partnership, and accountability. That starts with the region’s governors and other leaders coming together in person on December 10, where they must recommit to the Bay restoration partnership and pledge to update the Chesapeake Bay Agreement’s goals by the end of 2025.”
