WASHINGTON -- Preliminary test results blame blue-green algae for the deaths of about 1,000 fish in the Constitution Gardens pond on the National Mall.
John Emminizer with the D.C. Department of the Environment (DOE) says the algae becomes oxygen-starved at night and pulls oxygen out of the water, which can kill fish. He says when the sun comes up, oxygen is released back into the pond.
Emminizer says this algae only poses a threat to fish, and not to the public or other animals.
The National Park Service is currently working with the DOE to come up with a solution.
The park service says it has long stressed the importance of redesigning the pond in West Potomac Park to maintain a better ecological balance, according to NBC Washington.
The pond is at the top of the list for construction upgrades.
The Associated Press contributed to this report. Follow @WTOP on Twitter.
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