Several hundred fish found dead in pond on National Mall, recent extreme heat believed to be the cause https://t.co/K48wixjM0j
The pond averages only about 2 to 3 feet deep, shallow enough to make the water temperature shoot up quickly while removing dissolved oxygen from the pond. The D.C. area has been experiencing a heat wave in recent days, which has ushered in both conditions.
Meanwhile, when algae blooms forms during the heat, they remove yet more precious oxygen from the water when they die.
A similar fish death arose in 2013, park service officials noted.