Leonardo DiCaprio‘s latest eco-documentary “Sea of Shadows” doesn’t shy away from taking on Mexican cartels.

“For some of the guys there, he is state enemy number one at the moment,” said producer Wolfgang Knöpfler at the documentary’s premiere on Wednesday night at Neuehouse in Los Angeles. “The cartels don’t like him.”

Appian Way and DiCaprio executive produced the National Geographic documentary, which casts a spotlight on the little-known plight of the endangered vaquita, a species of porpoise that has become collateral damage in a poaching crisis raging in Mexico’s Sea of Cortez. Mexican crime syndicates have partnered with the Chinese mafia in the illegal fishing of the native totoaba, whose bladders are believed to have miraculous healing powers and fetch prices upwards of $100,000 on the Chinese black market.

Ensnared in nets meant for the totoaba, with their natural habitat decimated, the vaquita numbers have dwindled to less than fifteen. “Sea of Shadows” tracks the efforts of conservation groups, undercover investigators, journalists and the Mexican navy to save the vaquita from extinction and bring down the crime syndicates, while fending off deadly retaliation.

“It was the most dangerous film I’ve ever been involved in,” said director Richard Ladkani, who had previously partnered with DiCaprio on the 2016 Netflix documentary “The Ivory Game.”

He went on to credit DiCaprio for bringing attention to the vaquita. “He really cared about the vaquita and it was one of his ideas to do a movie about it because he wanted to save it,” Ladkani said. “He opened a lot of doors with the government and the president. But his name attached also means so much because the communication of the issue is so important and you need that in order to get people to see the movie.”

Ladkani also acknowledged iconic conservationist Jane Goodall with raising awareness of the documentary. Goodall, who was the subject of Ladkani’s 2010 documentary “Jane’s Journey,” introduced the film in front of the screening’s audience, which included DiCaprio, who quietly slipped in before the showing began.

“Jane is amazing, hosting this and giving us her name and all her reputation as a conservationist,” Ladkani told Variety ahead of the screening. “This is how we can make a difference. When we work together, we are strong.”

Standing beside Ladkani, Goodall said, “That film will be seen by hundreds and hundreds of Mexican people who never knew anything about it. Now they will. There’s hope within the country. Because that’s really where it has to start.”