Kendal Blust/KJZZ

Crew members from Sea Shepherd Conservation Society's ship in the Sea of Cortez are featured in the documentary "Sea of Shadows."

Kendal Blust/KJZZ

Sea Shepherd Conservation Society's patrol ship M/V Farley Mowat in the Sea of Cortez in September 2019.

A documentary about illegal poaching that’s threatening to wipe out the world’s most endangered marine mammal in Mexico’s Sea of Cortez has made its way to the Sundance Film Festival this year.

With fewer than 30 left, the small porpoise known as the vaquita marina is on the verge of extinction.

The new documentary “Sea of Shadows” delves into the threats against the little porpoise by looking at the world of illegal totoaba fish poaching in Mexico’s Sea of Cortez. The huge fish is known as the “cocaine of the sea” because its swim bladder is so lucrative on the black market in China.

But the nets used to catch the totoaba fish are considered the leading threat to the vaquita marina.

The documentary explores the world of Mexican drug cartels and Chinese smugglers who traffic the totoaba swim bladders. And the efforts of scientists, conservationists and fishermen who are fighting protect the vaquita marina.

The film, produced by Leonardo DiCaprio and directed by Richard Ladkani, is competing in the Sundance World Documentary category.