The National Oceanic and Atmospheric Administration’s National Marine Fisheries Service has approved MGM Mirage’s request to import two dolphins from Bermuda to display at Siegfried and Roy’s Secret Garden.

Two environmental organizations protested MGM Mirage’s application to import the dolphins. Born Free USA and the World Society for the Protection of Animals filed protests during a 30-day public comment period. Two dolphins died in the exhibit in the past year. The organizations claim the casino just wants to profit off the animals.

MGM denied the claim. It said it plans to import the dolphins for research purposes, and to allow students to study them. The company also said that by breeding dolphins, it could increase the dolphin population and facilitate continued research of the marine mammals.

The exhibit has a lackluster record when it comes to mortality rates; 14 dolphins have died since the exhibit opened in 1990. While five deaths were at or shortly after birth, others were attributed to a variety of causes, including pneumonia and pulmonary abscesses.