How is the truth constructed in the documentary blackfish?

Take 2013 documentary Blackfish, for example. This feature-length film about a trainer's death caused by a captive killer whale at SeaWorld in Orlando, Florida, placed the plight of captive orcas in the spotlight. It was the lightning rod for an animal rights campaign that could suddenly call upon celebrities such as Matt Damon, Harry Styles and Willie Nelson to condemn what animal welfare pressure group PETA has called a "tawdry circus".

The public's appetite for seeing captive orcas does appear to be waning. Since the documentary's release, SeaWorld visitor numbers, share price and profits have fallen and the park recently announced that it will end killer whale shows at its San Diego venue.

Revealing the new strategy, SeaWorld's chief executive Joel Manby said: "We are listening to our guests, evolving as a company, we are always changing. In 2017 we will launch an all new orca experience focused on natural environment [of whales]."