The CEO of SeaWorld Entertainment Inc. is stepping down from the post, as the parent company of SeaWorld San Diego embarks on plans to cut $50 million in costs amid dropping attendance at its 11 U.S. theme parks.

Officials of Florida-based SeaWorld Entertainment (NYSE: SEAS) announced that Jim Atchison will leave the CEO post effective Jan. 15. Company Chairman David D’Alessandro will serve as interim CEO until the board of directors selects a permanent successor to Atchison.

The company also announced plans for a restructuring that will centralize some operations and reduce duplication. The restructuring “will result in the loss of some positions” and the company will offer severance to those impacted, but officials did not specify how many people were being let go, nor where or when the cuts would take effect.

In August, SeaWorld Entertainment announced plans to nearly double the size of the killer whale enclosure at SeaWorld San Diego, part of a multimillion-dollar effort to address controversies and resulting business damage tied to concerns over its treatment of performing orcas.

The company recently announced that its revenue dropped 8 percent from a year ago, to $495.8 million, in its third quarter ending Sept. 30. Officials said the decline was driven primarily by a 5.2 percent decline in attendance, to 8.4 million, and a 2.9 percent decline in average revenue per customer, to $58.99.

When he leaves the CEO post, Atchison will become vice chairman of the board, and also serve as a consultant to the company related to international expansion and conservation initiatives. The company will also nominate Atchison to serve as board chairman for the nonprofit, independent SeaWorld & Busch Gardens Conservation Fund.

In addition to SeaWorld San Diego, which opened in 1964 and is the company’s oldest attraction, Orlando-based SeaWorld Entertainment also owns the Aquatica water park in Chula Vista.