54 rays die after malfunction at Illinois zoo – KGO

Brookfield Zoo officials said 54 stingrays died Friday after oxygen levels dropped in the zoo’s Stingray Bay habitat. Four southern stingrays and 50 cow-nose rays. They also closed the exhibit, escorting visitors from the area.

The Chicago Zoological Society said in a statement that most of the fish died on Friday afternoon.

Staff at the suburban Brookfield Zoo noticed the fish behaving erratically after an alarm which regulated temperature, ozone and oxygen went off, Sky News reports.

Bill Zeigler, a senior vice president at the society, said zoo staff worked hard to try to save the rays and were devastated by their deaths.

Despite all the emergency care given by the experience staff of veterinary employees at the zoo, and the fact that oxygen levels had been returned to normal by the staff – none of the stingrays were able to pull through the trauma they experienced.

Officials are analyzing the life support system to discern what caused the malfunction. All of the stingrays that died had been born in captivity.

The Chicago Zoological Society has decided not to reopen the stingray exhibit, which has been operating since 2007.

The water temperature had risen to 10 degrees warmer than its usual level, causing 16 of the 33 stingrays to die.