The Shedd Aquarium’s recently launched sea otter encounter program sold out its tickets from early May to August within a matter of hours Monday.

The experience allows visitors to privately view the popular marine mammals outside of the exhibit, feed the animals or watch them be fed and learn about sea otter biology and lifestyle.

The program launched in early March as part of the Shedd’s “Extraordinary Experiences” initiative, which offers exclusive interactions with several of the aquarium’s creatures, said Christy Sterling, the supervisor of the penguins and sea otters team at the Shedd.

“I think that people getting to see sea otters up close is special. People are learning a lot more about sea otters in a personal way and why they are important to our ecosystem,” she said.

Known as Chicago’s first sea otter experience, the program has received increasing public attention, said Shedd Aquarium spokesperson Johnny Ford.

In the previous two ticket-sale periods, 250 tickets were sold in total for spots from March through late April. Today, the Shedd sold more than 550 tickets.

“There is a growing awareness and interest in sea otters in Chicago, without a doubt,” Ford said.

The hour-long tour costs $109.95, or $94.95 for children younger than 12. Shedd Aquarium members pay $64.95.

Along with the behind-the-scenes look, participants can hear each animal’s story from Shedd staff, as three of the four otters at the Shedd were found stranded as young pups.

Shedd staff have cared for 10 sea otters over the past four decades, starting with a group that came to the aquarium after the catastrophic Exxon Valdez Oil spill in 1989, Sterling said.

Sea otters are identified as a federally protected endangered species.

“We’ve worked to protect sea otters because they are vital to the ecosystem,” said Sterling. “It’s important to bring awareness to people.”