Can conservation save our ocean? | The Economist

The ocean is facing its greatest ever challenge - overfishing, pollution and climate change are all threatening the health of a resource on which the whole world depends.
The crew of this ship is on a mission to try and save one of the most endangered sea creatures on the planet. They’re in the middle of a marine protected area in Mexico - a conservation zone where certain types of fishing are banned.

Local fishermen are poaching a species of fish that is so highly prized in China, they can make tens of thousands of dollars in just one night. With ocean life under threat from overfishing, pollution and climate change, could marine protected areas be the answer? 
Near the Mexican fishing town of San Felipe, on the The Upper Gulf of California...
Conservation group, Sea Shepherd is working with the authorities to help enforce a Marine Protected Area - or MPA. A designated section of ocean to be conserved, managed and protected.
Maintaining rich, diverse ecosystems is key for the health of the Ocean - and ultimately the survival of humanity. But ocean life is under threat. From plants to micro-organisms and animals, species are disappearing forever.

Marine Biologist Patricia Gandolfo and the rest of the Sea Shepherd crew are here to stop poachers.
Caught up in the nets of the criminal gangs and local fishermen is one particularly rare porpoise - the Vaquita. Worldwide there are thousands of sea species currently threatened with extinction. Losing just one species from the food chain can have a disastrous effect on an entire ecosystem.
After it’s sold on, the Totoaba’s swim bladder can fetch up to $100,000 a kilo in China, where it’s prized for its medicinal properties.
Critics disapprove of Sea Shepherds use of direct-action tactics in some of their campaigns, but in the Gulf of California, their presence is welcomed by the Mexican government.

Globally, the fishing industry employs 260 million people, but many more subsistence fishermen depend on the ocean for their income. Local fisherman here claim protecting the ocean has limited how they can fish, destroying their way of life. Yet doing nothing may ultimately present more of a threat to their livelihoods.
Currently Marine Protected Areas make up only 3.6% of the world’s ocean but a growing number of scientists are calling for 30% to be protected by 2030.

Cabo Pulmo now has a thriving eco-tourism and diving industry. The environmental rewards provided by the MPA to the local community have been valued at millions of dollars a year - Far more than they ever made from fishing. The ocean is facing its greatest ever challenge - overfishing, pollution and climate change are all threatening the health of a resource on which the whole world depends. Marine protected areas can come in many forms. But if they are to be effective, they must align the need for conservation with the needs of those who depend on the ocean for survival.
In order to avoid disaster–and to ensure a sustainable supply of fish for the future–far more of our ocean needs urgent protection.