The new documentary Sea of Shadows uses the incredible story of how environmental activists and the Mexican military are fighting cartels to save an endangered whale to highlight what the extinction of one species means for the future.

Produced by Leonardo DiCaprio and directed by Richard Ladkani (The Ivory Game), Sea of Shadows opens this Friday. My review is at Slant:

The whale in question is the vaquita, a dolphin-like creature endemic to the Gulf of California. At the time of this film’s making, there were most likely less than 15 left alive. Not a target of hunting themselves, the vaquitas had the bad luck of swimming in the same waters as the heavily fished totoaba and dying in the nets meant to catch their more valuable neighbors. The vaquitas are ultimately collateral damage in an illegal fishing scheme driven by greed, economic insecurity, failing security apparatuses, interstate organized crime, and more…

Here’s the trailer: