NEW YORK (MarketWatch) -- SeaWorld Entertainment confirmed Friday that it will upgrade its killer whale tanks, succumbing to public pressure that has been mounting since the release of CNN’s “Blackfish” documentary last year.

Shares of the theme park operator are down 35% since the company axed its outlook and reported a decline in attendance at its flagship San Diego park on Wednesday.

SeaWorld SEAS, -1.11% directly attributed disappointing earnings to “adverse publicity” surrounding the treatment of its Orca whales. A documentary called “Blackfish” released last year highlighted less-than-ideal habitats for the killer whales it holds in captivity, outraging activists and triggering lawsuits seeking to ban killer whale captivity.

“Adverse publicity concerning our business generally could harm our brands, reputation and results of operations,” SeaWorld said in earlier this week.

The Orlando-based company plans to nearly double the size of the tanks that house its Orcas in San Diego to about 10 million gallons of water and a depth of 50 feet.

Animals rights group PETA, which is pushing for the complete release of the whales, was not convinced.

“This is a desperate drop-in-the-bucket move,” a PETA spokesperson said. “It will not save the comapny.”

SeaWorld admitted that the new facilities still wouldn’t satisfy some of the company’s biggest critics, many of whom are calling for the complete ban of Orcas in captivity. But it says there are benefits to expanding, not just completely abandoning, Orca tanks, including spurring new scientific research about the species.

While SeaWorld says this project was conceived before the release of “Blackfish,” this isn’t the first time powerful documentaries and loud-spoken activists have sparked change to industry practices.

Movies like 2004’s “Super Size Me” have roiled entire sectors, prompting change. Morgan Spurlock’s “Super Size Me” documentary, which documented the negative health transformations of a man who only ate super-sized McDonald’s meals for an entire month, seemed to have awoken a sleeping American public, previously unconcerned about rising obesity rates.

McDonald’s MCD, -1.03% sales were initially pressured from the backlash a decade ago, ultimately leading the company to phase out super-sized fries and sodas. Since then, a massive industry-wide movement has led to healthier alternatives at burger joints, such as apples and carrots.

Shares of McDonald’s have risen 262% since 2004. Today, the company is valued at a colossal $92 billion.

Construction on the San Diego SeaWorld facility is set to begin next year and be completed by 2018. Similar upgrades will follow at its SeaWorld locations in Orlando and San Antonio.

Among the features of the new facilities will be a “water treadmill” system, a moving stream of water that enables the Orcas to swim in place, getting more exercise.

Wells Fargo downgraded SeaWorld on Thursday to market perform from outperform, saying the competitive pressures “appear modestly greater than thought.”

“Media fallout from extreme animal rights activists in CA appear to have materially impacted June San Diego attendance/admission results,” Wells Fargo analyst Tim Conder said in a note to clients.

JPMorgan and Wells Fargo both lowered their revenue estimates on SeaWorld, though JPMorgan maintained its neutral rating.

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