DES MOINES, Iowa (AP) — A new exhibit at an aquarium in Iowa that had intended to showcase the beauty of the Gulf of Mexico will instead be void of life to underline the environmental impact of a massive oil spill in the ocean basin.

The 40,000-gallon aquarium at the National Mississippi River and Aquarium in Dubuque, about 1,000 miles from where the river dumps into the Gulf, was supposed to have been teeming with sharks, rays and other fish. Two smaller tanks were to show a seagrass bed and coral reef.

It may be the only time that people have ever seen a major aquarium that, instead of showing its fish, is showing an environmental disaster," said Jerry Enzler, the museum's executive director.

The main tank — the size of a school bus — will contain water and artificial coral, its sides adorned with window stickers that look like oil.

It will look like the oil is sinking down and about to cover the coral, which will kill the coral," Enzler said.

Anywhere from 67 million to 127 million gallons of oil have spilled since the April 20 explosion on the Deepwater Horizon rig that killed 11 workers and blew out a well 5,000 feet underwater. BP PLC was leasing the rig from owner Transocean Ltd.

The Iowa exhibit, which opens Saturday as part of the museum's $40 million expansion, will feature a video showing the oil spill unfolding.

We want everyone to pause and consider the delicate balance of life in our oceans," Enzler said.

It will be a powerful message, said Steve Feldman, a spokesman for the Association of Zoos and Aquariums, a nonprofit accrediting group based in Siver Springs, Md.

The upclose connection to animals is very powerful. It's part of how we teach our children about nature and in this case, man's impact on nature," Feldman said.

The Iowa museum reached out to the National Oceanic and Atmospheric Administration when it was considering the exhibit, said Louisa Koch, the education director for NOAA.

There have been many, many exhibits highlighting the impacts of hurricanes and tsunamis, but I think this is a really stunning way to go. The (disaster in the) Gulf is of unknown but certainly significant impact. I can think of no exhibit like this," she said.

The museum also displays a 92-foot map of the Mississippi River featuring a graphic of the oil spill that will grow as the disaster widens.

Many times people view aquariums as a beautiful picture, almost a screen saver, so to speak," Enzler said. "This is no screen saver.