On July 10th, 2015, the Brookfield Zoo in Chicago, Illinois made the announcement that the stingray exhibit would be closed after a fatal accident that claimed the lives of 54 stingrays. According to zoo staff, the accident was a result of a dangerous drop in oxygen levels. Despite their efforts to raise the oxygen levels, 50 cownose stingrays and four southern stingrays died. The exhibit will now remain closed for the rest of the season.
The Brookfield Zoo's stingray exhibit is a shallow pool that allows visitors to not only view these winged beauties, but to touch and feed the stingrays as well. The exhibit has been in operation since 2007, but now sits empty. The only thing visitors can ask themselves is why.
The accident has been credited to a malfunction of the life support system in the tank. Animal care officials and veterinary staff arrived on the scene as soon as the low oxygen levels were discovered in order to care for the stingrays while maintenance staff tried to fix the system. However, it was all too little, too late.
“We are devastated by the tragic loss of these animals,” said Bill Zeigler, senior vice president of animal programs for the Chicago Zoological Society, which operates the zoo. “Our staff did everything possible to try and save the animals, but the situation could not be reversed.”
The Brookfield Zoo's Facebook Page also tried to go into more depth to explain what happened, “there is an automated aqua-guard system that alerts the manager in the event of a change in the water quality. The aqua-guard tests the life support system every 15 minutes and checks for the temperature, pH levels, oxidation reduction potential, ozone level, and dissolved oxygen.”
This is, unfortunately, not the first incident of system malfunction in the exhibit. In 2008, 16 stingrays perished when the waters of the tank rose to a lethal level.