Visitors to the Shedd Aquarium can welcome home Chicago's menagerie of marine mammals to their Oceanarium habitat, scheduled to reopen on May 22 after extensive renovations.

The animals will return on chartered aircraft and, in the case of the whales and dolphins, in specially made cradles. Shedd’s animal staff members also travel with each animal.

“It’s a lot like traveling with a child. It can be scary, but if mom or dad is there, it can be a fun adventure,” said Ken Ramirez, senior vice president of animal collections at Shedd.

The renovations included maintenance and resurfacing of the habitat pools and promise an environment more like the ocean for everyone. The Oceanarium will debut a Pacific Northwest exhibit, featuring more interaction wit hthe animals and a new Polar Play Zone especially designed for young children.

This past week, staff at the Shedd tackled the mammoth task of refilling the tanks and adding salt and chemicals to the 3.2 million gallons of  water that fill the pools and habitats of the Oceanarium.

The habitat's residents — seven Beluga whales, four Pacific white-sided dolphins, five sea otters and two sea lions — are scattered now, with most on loan to other zoos and aquariums. The whales and dolphins have spent their vacation at the Mystic Aquarium in Connecticut and the sea otters are currently residing at the Minnesota Zoo in St. Paul.  

“Because the animals have lived here before, it isn’t the same as if it was a brand new building,” Ramirez said. “Seven to 10 days should be enough for them to adjust, but we want to bring them in a few weeks before [the opening], if possible.”

Workers at the facility have been adding to the water bags of a product called Instant Ocean — a mixture of salt, magnesium chloride, potassium chloride and other chemicals. The combination closely mimics the chemistry of the ocean and takes the guesswork out of creating water that’s just right for the marine mammals.

“We’re trying to recreate ocean-like water,” said Ramirez. “This is the animals’ home and we want it to be as perfect as possible.”

Previously, the water in the Oceanarium was treated with salt and chemical compounds separately, the typical process for large aquariums, according to Bob Wengel, an aquarium operations manager. The premixed compound makes maintaining the habitat’s water easier for Shedd staff.

“Over time, the water loses elements and we don’t have to figure out what’s lost or what’s gained, it’s already done for us,” he said.

The process of adding the bags of chemicals, which weigh over a ton, to the water is actually going more quickly than anticipated, according to Brad Popovich, Shedd’s vice president of facilities.

The project was scheduled to take 10 days, but Popovich anticipates the work will be completed Wednesday. Initially, workers expected to work 24 hours a day and to distribute 2 bags of Instant Ocean per hour. However, they have been able to increase their speed to four bags an hour and approximately 55 bags, or almost 70 tons of Instant Ocean per day.