The Chesapeake Bay Dead Zone remains within averages, according to a new report.
An increase of nitrogen from things like polluted runoff and algae blooms, reduce oxygen levels and create dead zones.
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Virginia Institute of Marine Science Professor Marjorie Friedrichs said measured improvements take time, but its a good sign the dead zone isn't getting worse.
"We are encouraged by the fact that it is only average and it is not any worse because the precipitation and the runoff in the spring was actually unusually high," Friedrichs said.
They're fighting against warmer temperatures from climate change, which also contribute to a larger and longer-lasting dead zone.
"Fish are going to avoid that area, crabs, because they can swim away," Friedrichs said. "Other shellfish are not going to be able to survive there with the very low oxygen, so it's really a habitat issue."