Stingray Bay habitat at Brookfield Zoo closed for season after more than 50 rays die

BROOKFIELD – The deaths of 54 rays at the Brookfield Zoo's Stingray Bay habitat will likely cause its closure for the rest of the summer, according Bill Zeigler, senior vice president of animal programs for the Chicago Zoological Society, which operates the zoo.

The exhibit was closed July 10 after oxygen levels in the habitat dropped, which led to the deaths of four southern stingrays and 50 cownose rays, according to the zoo.

On July 13, Zeigler said the zoo is in the early stages an investigation into the equipment that regulates the environment in the Stingray Bay habitat, as well as investigating if a biological cause was responsible for the rays' deaths.

According to zoo officials, there was a drop in the oxygen level at the habitat June 10, which zoo staff were alerted to by an alarm system at 1:45 p.m. that monitors the habitat.

Zeigler said staff began to notice the rays acting strange when the alarm went off. Zeigler said the alarm system is monitored 24/7 by a zoo staff member and that five staff members are always present at the exhibit.

Veterinary staff provided medical treatment to the rays, and immediate action was taken by animal care staff to return the oxygen levels. According to Zeigler, appropriate oxygen levels were restored within 20 minutes of the alarm sounding, but the damage was already done.

“We are devastated by the tragic loss of these animals,” Zeigler said.

This is not the first time a large number of rays have died in the exhibit. In 2008, 19 rays died after a heater malfunctioned in the exhibit, Zeigler said.

The exhibit opened in 2007 and allows patrons of the zoo to feed and touch the rays as they swim.

Zeigler said the zoo's staff has a close connection with the animals and described their relationship as "like family."

On social media, commenters both blamed the Brookfield Zoo for the rays' deaths – with some commenters blaming zoos more generally – while others said they supported the work of the Brookfield Zoo and others.

Zeigler said the zoo was grateful for the "outpouring of support" they received from members and patrons following news of the ray's death. He also stood behind the zoo's actions and the Chicago Zoological Society's mission.

"We believe in what we do," Zeigler said of work done by the Chicago Zoological Society.

Zeigler said the zoo continues to do important work in creating meaningful connections between patrons and the larger animal world, as well as being involved in leading research and as a voice for conservation efforts.

The rays that died at the exhibit were born in captivity. Zeigler said he believed the exhibit would reopen with rays again, as it is a popular feature of the zoo. But, he said, that decision would come at a later date after a larger discussion between zoo officials.