The Columbus Zoo and Aquarium will seek new leadership after CEO Dale Schmidt resigned last week.

The Columbus Zoo and Aquarium will seek new leadership after CEO Dale Schmidt resigned last week.

Zoo Chief Operating Officer Tom Stalf has assumed the role of interim president and CEO after Schmidt resigned during an Aug. 21 meeting of the board of directors for "personal reasons." His resignation was effective immediately.

It's the fourth time in five years the zoo has changed leaders.

The board will announce plans regarding the permanent appointment of a new chief "at a later date," a press release said.

Stalf, 44, joined the zoo as COO in July 2010. He previously served as director of the Niabi Zoo in Coal Valley, Ill., for 18 years.

He said it's an "honor" to be appointed to the zoo's top leadership role.

"It's very humbling, and it's something I've always wanted to do," Stalf said.

"We are leaders in what we do, and there's no place on Earth that I would want to be associated with other than the Columbus Zoo."

He said he hopes the zoo's board of directors promotes him to a permanent role as CEO, but he's currently focused on daily park operations.

"I hope that I get the opportunity to take the 'interim' off my title, but for now, my main goal is to ensure that the zoo is doing very, very well and providing a great experience for the community," he said.

Stalf lives north of the zoo in Ostrander on a 20-acre farm with his wife and two children.

In a written statement, board Chairman Tim May said Stalf will work closely with Director Emeritus Jack Hanna during the transition.

"Because of his years of experience at the Columbus Zoo and the positions he has held prior to coming to central Ohio, we are confident in Tom's leadership and know the transition will be seamless," May wrote.

Schmidt stepped in as CEO in 2009 after former director Jeff Swanagan died of a heart attack. He first filled the role on a temporary basis but was promoted to a permanent position.

He led the zoo in 2010 when it saw record-breaking attendance and opened the $20 million Polar Frontier attraction.

More recently, he led operations at The Wilds animal park in Muskingum County, and announced the construction of the $30 million Safari Africa exhibit set to open in summer 2014.