Guests stare down an aquatic animal at the Shedd. View Full Caption Shedd Aquarium

MUSEUM CAMPUS — Shedd Aquarium will scrap its tiered admission passes in favor of flat rates, hoping simpler admission fees will bring more visitors, though some fish fans will pay more.

The aquarium at 1200 S. Lake Shore Drive will ask the Chicago Park Board of Commissioners this week to approve the new, one-size-fits-all prices.

Under the proposed flat rate schedule, city residents 12 or older would pay $19.95 while children three to 11 years old who live in the city would pay $14.95.

Adults who reside outside the city would pay $39.95; non-resident children's admission would be $29.95.

Shedd's current tiered approach allows visitors to pay for access to more exhibits. City residents currently pay $5 for general admission, $27.95 for a "Shedd Pass" for adults and $36.95 for an "All-Access" pass.

Non-city residents now pay $8 for general admission, $30.95 for a "Shedd Pass," and $39.95 for an "All-Access" pass.

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The new pricing plan will "accommodate more people and provide a more generous and affordable experience," said Andrea Rodgers, the Shedd's vice president of communications and public relations.

"We are always striving to improve and enhance the guest experience and expand access to Shedd," she said in an email.

Shedd's current $5 general admission passes allows access to the aquarium's "main-floor habitats," according to its website. The Shedd Pass allows admission to special exhibits such as "Caribbean Reef" and the "Polar Play Zone," while All-Access passes include the Shedd's "Amphibians" exhibit, its 4D theater experience and the opportunity to touch a stingray.

The Shedd says the change will make buying tickets easier, eliminate cumbersome internal ticket checkpoints, and allow the aquarium to open up all its exhibits during its 52 free days a year for Illinois residents.

The new fees do not include a $4.95 charge for the Shedd's 4D theater experience.

The Shedd drew nearly 2 million people last year, with 800,000 visiting for free or with a discount, officials said.

The Shedd says it has not changed its admission fees since 2000. The park board will vote on the new fees Wednesday. The new fees would take effect July 1 if approved.