Joel Manby, SeaWorld Entertainment Inc.'s chief executive, has resigned.
John T. Reilly, who oversees parks operations, has been tapped as interim CEO.
Previously Reilly was president of SeaWorld San Diego, a role he held from 2010 through April 2016.
The Florida-based theme park company announced the leadership shakeup on Feb. 27, the day of its fourth-quarter earnings report, which revealed attendance was down 2.7 percent from a year ago.
The company said it lost $20.4 million in the last quarter of 2017, more than its loss of $11.7 million in the same quarter the year prior.
SeaWorld also reported a $202.4 million loss in 2017, including a non-cash charge-off of $215.1 million, on revenues of $1.26 billion.
The company said it engaged an executive search firm to find a successor to Manby.
Yoshikazu Maruyama, chairman of the company's board of directors, was selected as interim executive chairman.