The decision came after fourth-quarter results showed a declining attendance – a 2.7 percent loss from the same time last year, to be exact, with 4.26 million attending the various SeaWorld parks. It also showed a decline of 5.5 percent in full-year attendance from 2016 to 2017, according to Business Insider.
In a press release, Manby "agreed that this is the right time to identify a new CEO as the Company enters its next phase of intensified focus on execution and growth."
SeaWorld has seen a steady decline in attendance since the release of the documentary Blackfish, which exposed some of the cruelties shown to orcas at the parks.
"Over the past three years, Joel has worked tirelessly to strengthen SeaWorld's position as a company that combines entertainment, education, and its important mission to protect marine life and the oceans. Our improving fourth quarter and positive year-to-date trends give us confidence that the steps we have taken position us well for 2018," current Chairman of the Board Yoshikazu Maruyama said in a statement.
Under Manby's watch, the troubled orca Tilikum died, SeaWorld ended their controversial orca breeding program, the company laid off a significant portion of the staff, and they transitioned their animal shows into a more "infotainment" bent.
In the meantime, Chief Parks Operations Officer John T. Reilly will be acting CEO until an outside consulting firm finds a permanent replacement.