A dozen stingrays that were found dead at Zoo Tampa last month likely died from a lack of oxygen due to a malfunction in the touch tank.
Zoo officials released the findings of their investigation Tuesday.
It shows the 12 stingrays died on May 27 from what officials describe as a super saturation event that caused "gas bubble disease" — or fatal gas embolisms in the rays. That's when gas bubbles enter the blood stream, similar to the "bends" that scuba divers can contract.
The sting ray deaths occurred overnight, but the cause was not immediately known. Officials said the oxygen levels in the water had corrected themselves when the water was tested the next morning.
Possible causes of the gas bubbles include a system malfunction or a crack in a pipe that went un-detected during a daily check.
The touch tank will not be reopened, officials said. It will be replaced by an updated habitat with a new, upgraded water management system.