The issue of orcas in captivity has been an on-going one for many decades. For years, orcas and other marine life have been used as entertainment at water-themed amusement parks such as SeaWorld and have had their physical and mental health compromised in the process. Since the 1960's there have been at least 40 reported killer whale attacks on trainers, a result of poor mental health and aggression due to the conditions to which these creatures faced. The 2014 documentary Blackfish exposed the elaborate series of cover-ups created by organisations such as SeaWorld and gave insight into how the industry affects these animals.