SeaWorld shares sink amid concerns over killer whale displays

Theme park hit by concerns over the treatment of killer whales as shown in the award-winning documentary 'Blackfish'

Tilikum in a scene from 'Blackfish' (AP)

Shares in SeaWorld plummeted in New York trading after the American marine theme park operator admitted animal rights protests had hit visitor numbers in the second quarter.

The stock plunged more than 30 per cent on Wednesday as the company revealed it expects full year revenue to fall by up to 7 per cent, citing the "recent media attention" derived from a California bill proposal seeking to end killer whale shows at Sea World.

Last year, Democrat Richard Bloom introduced the bill after watching Blackfish, a documentary exploring the death of whale trainer Dawn Brancheau, who died after a 12,000-pound orca known as Tilikum pulled her underwater at SeaWorld in Florida.

The documentary, watched by more than 20 million people after it aired on CNN in the US last year, raised concerns about the treatment of killer waves in captivity at tourist attractions and argued that Tilikum's violent behaviour was the result of abuse and harassment. SeaWorld dismissed the documentary as "inaccurate and misleading".

SeaWorld also lost an appeal at the US Court of Appeals for the District of Columbia, which ruled that interactions between its employees and killer whales should be restricted and argued that the company had violated its duties as an employer by exposing its trainers to “recognized hazards”.

The company reported net income of $37.3 million, or 43 cents per share, in the three months to June, missing analysts' estimates of 60 cents per share. Revenue fell 1.5 per cent to $405.2 million for the quarter. Analysts expected $447.7 million.