By Madina Toure
The city Parks Department said Kissena Lake in Flushing is safe for fish again after at least 150 fish died last week due to an algae bloom following flash flooding.
The fish died on the night of Aug. 11 and the morning of Aug. 12 after flash flooding led to a blue-green algae bloom, which caused oxygen levels in the lake to drop, Parks said.
Although it is not known exactly which species were killed, the fish in the pond include carp, black crappie, largemouth bass, yellow perch and American eel.
Parks said the number of fatalities is likely to increase as fish that died deeper in the water continue to float to the top of the water, but insisted that oxygen levels have been restored and the water is once again safe for fish.
“NYC Parks staff have worked quickly to address this issue, bringing in aerating water pumps and coordinating with DEC to investigate further,” Sam Biederman, a spokesman, said in a statement.
The DEC said it sent a sample of fish to Cornell University for testing and it confirmed the fish likely died from anoxia, a condition that develops when water is depleted of dissolved oxygen. But the university said it did not notice anything indicating a disease.
Kissena Lake is fed by natural wells, which normally provide freshwater conducive to many fish species. After a relatively dry period, the sudden rain flushed a large accumulation of sediment and debris into the lake, creating the algae bloom.
James Cervino, CB 7’s environmental chairman and president of the College Point Transfer Station Advisory Board, said the Parks Department is correct in its analysis of the situation, but it is missing a key point: the nutrient pollution that causes the oxygen levels to decrease in the water.
This occurs through a process known as eutrophication, when water bodies receive excess nutrients that stimulate excessive plant growth.
Cervino said this is typically due to overfertilizing from fertilizers and sewage, although he was unsure of whether either were the source of the problem in Kissena Lake.
“They didn’t die just of low oxygen,” he said.
Reach reporter Madina Toure by e-mail at mtour
