The parks' marine mammal collections have been the subject of public debate over the years. The 2013 documentary film "Blackfish", produced after a SeaWorld Orlando trainer was killed by one of the park's orcas, led to initial decreases in attendance, profits and the company's share price. In 2018, SeaWorld's attendance and revenue began to recover with the addition of new rides, shows, and animal exhibits at its parks, as well as increased marketing about the parks' conservation and rescue efforts. It is a major theme park competitor to Six Flags, Cedar Fair, Walt Disney Parks & Resorts and Universal Parks & Resorts.