PHOENIX (AP) — After the death of a fourth dolphin, a Phoenix-area aquatic facility announced Tuesday that it will temporarily close for a reevaluation by an outside panel of experts.

Officials with Dolphinaris Arizona said the voluntary closure will start Friday and there isn't an immediate timetable for reopening.

They said in a statement that an investigative panel that includes veterinarians, pathologists, water quality experts and animal behavior specialists will assess all aspects of the facility and operations and report their findings and any recommendations.

"We hope to find a long term solution for the welfare of our dolphins," said Dolphinaris general manager Christian Schaeffer de Leon.

More than 100 protesters demonstrated Saturday outside the facility located on tribal land near Scottsdale, calling for its closure after a 22-year-old dolphin on loan to Dolphinaris Arizona died last Thursday.

Dolphinaris hired an external pathologist to determine the cause of death and said it occurred after the dolphin's condition began deteriorating and he had difficulty swimming, eating and breathing.

Dolphin Quest, the company who loaned out the animal, terminated its contract with Dolphinaris Arizona the day after the death.

Two of the facility's four remaining dolphins are being returned to Dolphin Quest while the other two will be moved to another licensed facility while Dolphinaris Arizona is being evaluated.

An 11-year-old dolphin died in December from a chronic illness due to a parasite called Sarcocystis that she had for six years.

In May 2018, a 10-year-old dolphin at Dolphinaris died from a bacterial infection. And in September 2017, a 7-year-old dolphin died at the facility from a muscle disease.

Calls to the U.S. Department of Agriculture's animal and plant health inspection service seeking for comment on the Dolphinaris situation weren't immediately returned Tuesday.

Dolphinaris, part of the OdySea In The Desert complex on the Salt River Pima-Maricopa Indian Community near Scottsdale, opened in October 2016.

Dolphinaris has additional sites in Mexico. Dolphin Quest operates its own locations in Hawaii and Bermuda.