Chesapeake Bay dead zone shrinks
Low rainfall contributed to the change.
An area in the Chesapeake Bay that doesn't get enough oxygen to support marine ecosystems shrunk this year, according to new data released by Old Dominion University, the Virginia Institute of Marine Science and the Maryland Department of Natural Resources.
The dead zone was the smallest recorded since monitoring began in 1985.
The problem spots are created by debris and agricultural runoff that sweep nutrients into the Bay, which then feed algae, potentially creating algal blooms that remove dissolved oxygen from the water.
“While the smaller dead zone this year is a promising sign, we must remember the major challenges that lie ahead,” said Joe Wood, a Virginia-based senior scientist with independent advocacy group Chesapeake Bay Foundation. “The mere existence of a dead zone in the Bay is cause for alarm, and a sign that we must still dramatically reduce pollution flowing into the Bay.”
Wood added that Bay states — Virginia, Maryland, Delaware, West Virginia, Pennsylvania and New York — and Washington, D.C., are “behind in reducing polluted runoff from agriculture.”
An EPA report released in July said the Chesapeake Bay Program — a consortium of governments within the Bay’s watershed — isn’t likely to meet 2025 goals to reduce the amount of pollutants flowing into the body of water. All of the nitrogen, phosphorus and sediment that end up in Bay are tallied against the total maximum daily load — the amount of pollutants that can be present while water still meets Clean Water Act standards.
The federal agency said it doesn’t have the power to act, but it also “has not updated its pollution-reduction strategy or led the Chesapeake Bay jurisdictions in updating the 2025 goals and pollutant-reduction deadlines.”
Below-average precipitation for the region during the time data was collected contributed to the dead zone shrinking, according to the newly released report. That means, polluted runoff was likely lower — but chemicals used in farming near bodies of water connected to the Bay didn’t necessarily decrease.
James River Association President Bill Street said having a relatively dry year was a “key driver” in shrinking the dead zone. But it’s a multifaceted equation that also includes water temperature, wind and air pollution.
“I think [the report] demonstrates the progress being made based on the investments that Virginia has been making into the clean water programs — particularly upgrading wastewater treatment plants, but also now investing in agricultural practices and stormwater practices are really important,” he said.
The National Oceanic and Atmospheric Administration is forecasting a wet winter for the region, which could play a role in runoff and again increase the Bay’s dead zone. But Street has a long-term view of yearly predictions like that.
“In addition to the pollution controls that we've been putting in place, hopefully we are approaching a point where the system becomes more resilient in and of itself,” he said, “as underwater grasses become re-established, as we continue to install forested buffers along streams and creeks, and in wetlands along the tidal waters.”