By Marissa Parra

CHICAGO (CBS) — The Shedd Aquarium is turning 90 years old and is using virtual celebrations to celebrate all things under the sea all weekend.

CBS 2’s Marissa Parra got to see what has changed during the COVID-19 pandemic and what it will be like once the doors reopen.

“I think they really miss people,” Peggy Sloan said of the penguins. “With the penguins, they are very interested in where people are.”

On its 90th birthday week, few things about the Shedd Aquarium resemble what it looked like this time last year.

“It’s surreal,” said Sloan. “It’s hard. It’s very hard.”

Like zoos and aquariums around the country, that peaceful quiet is bittersweet. It’s hard when the ticket counter has been closed for months. Ticket admissions help pay for 70% of the $765,000 a week is takes to keep Shedd Aquarium running and animals safe.

“Our commitment to the animals doesn’t change. Our ability to connect people in person does,” Sloan said.

Few have navigated keeping that connection alive as well as Shedd has. Video of their penguins roaming the empty aquarium captured hearts on every continent, racking up millions of views around the world.

They hope those views translate to bringing people back in person once the time comes.

“The greatest con is the unpredictability and how to bring them back here and have them feel safe and comfortable,” said Sloan.

It may look like fun and games, but the animal care staff has been hard at work, even making time for some spring cleaning.

“Everything is going to be really clean! Our teams have had a chance to do some maintenance on exhibits they wouldn’t have been able to do when we were open to the public,” she said.

Staff and patrons will wear masks. The lunch area will be moved outside with tables .

“It’s really hard sometimes to be here without the people because that why we’re here, to build that connection,” Sloan said.

While Shedd is closed to the public, workers are still there doing many regular activities including conducting routine medical exams, doing enrichment activities with the animals, publishing research studies and rearing endangered fish for eventual release to bolster natural populations. They have also created an entirely new educational series called Stay Home with Shedd for virtual visitors everywhere with a variety of resources to keep kids and families in reach of science-driven, hands-on activities.

In late March the Illinois Department of Public health asked to borrow Shedd’s microbial ecology lab’s state of the art and rare DNA extraction device called the KingFisher. Aquarium officials said the device has “significantly increased the state’s ability to simultaneously process large volumes of COVID-19 tests.

Like other aquariums and zoos around the country, including Brookfield Zoo, Shedd will be using a timed entry and exit system upon reopen.

Donations to support Shedd’s reopening can be made the aquarium’s website.