Rating: 4.5/5.0

Polar ice is melting, seas are rising, and millions of species are going extinct. Humans and our unrelenting desire for capital have been the catalyst of this mass destruction. Oftentimes, it feels like all hope is lost, that the Earth is too far gone. Stories of conservation efforts come from across the globe, from devastation about the loss of the last male northern white rhino to the hopeful recovery of the humpback whale population.

“Sea of Shadows,” the newest eco-documentary from National Geographic and executive producer Leonardo DiCaprio, is different. Directed by the experienced Richard Ladkani, the film feels more like an action thriller than an environmental tale, complete with epic boat chases, blurry mafia informants, rampant government corruption and violent public uprisings. The film is only able to stay grounded in reality because, well, it’s the truth.

Stunningly shot and edited, with the perfect mix of action sequences and sentimental, heart-achingly beautiful shots of underwater paradises, the film showcases the vibrant parity of life and death in the Sea of Cortez, the northernmost body of water between Baja California and Mexico. Here, whale conservation has become a military mission — the largest mission ever to stop an animal extinction.

The totoaba fish has been dubbed the “cocaine of the sea” because of the exorbitant prices its bladder fetches in Chinese black-market apothecaries. In recent years, it has become the most valuable commodity in the small town of San Felipe. Fishing it has become illegal because of the ecological destruction that huge nets have caused, creating a violent black market of poachers from Mexico’s most deadly cartels.

The biggest casualty of the trade, both literally and metaphorically caught in the crossfire, is the vaquita — a beautiful and rare porpoise. Two years ago, there were 100. When the film takes place, there are 30. Now, there are even fewer.

The film follows a variety of people dedicated to stopping the vaquita’s extinction. There’s Andrea Crosta, the executive director and co-founder of Earth League International, who has recruited the world’s best organized crime agents and criminal informants. They work to follow the illegal trade of totoaba from Mexican cartels all the way to elite Chinese businessmen. Crosta partners with Mexican journalist Carlos Loret de Mora, who receives death threats for exposing the corruption of the Mexican government and pressuring it to crack down on the illegal trade.

We watch the Sea Shepherd crew from “Whale Wars” pull up huge fishing nets in the dead of night, evading shots from militant poachers. Immediately after, the film cuts to Dr. Cynthia Smith and her team, throwing nets around a vaquita, trying desperately to put the whales in captivity until it is safe enough to return them to their home. But this is a wild animal that does not belong in captivity. After a tear-jerking, difficult-to-watch battle to save this beautiful animal, the team must accept that this is not the method to protect these creatures.

It’s a film about watching the world fall apart and doing something about it. As Sea Shepherd first mate Jack Hutton explains, “To anyone who says one person cannot make a difference, 30 people here have saved thousands of lives.” Each individual featured has a distinct reason for doing this work, but it always returns to the same narrative — the vaquita is a symbol. 

This is an extinction happening in real time, a terrifying microcosm of what’s happening to our whole planet. Saving the vaquita will not mean the survival of the planet. But its extinction will signal the destruction of an entire ecosystem, a dangerous chain reaction in an already terrifyingly unstable ecological climate.

In lengthy voice-overs, the film’s characters emphasize: “We aren’t a virus here to kill our host. As a species, that is unacceptable. If that happens, we should be ashamed.” Maybe it’s not the biggest battle on earth or the most important, but “Sea of Shadows” reminds us of the beauty of our home planet and the depths we must go to in order to save it.