The report also found that strategically conserving some marine areas would not only safeguard imperiled species but sequester vast amounts planet-warming carbon dioxide, too.
For the first time, scientists have calculated how much planet-warming carbon dioxide is released into the ocean by bottom trawling, the practice of dragging enormous nets along the ocean floor to catch shrimp, whiting, cod and other fish. The answer: As much as global aviation releases into the air.
While preliminary, that was one of the most surprising findings of a groundbreaking new study published on Wednesday in the journal Nature. The study offers what is essentially a peer-reviewed, interactive road map for how nations can confront the interconnected crises of climate change and wildlife collapse at sea.
Protecting strategic zones of the world’s oceans from fishing, drilling and mining would not only safeguard imperiled species and sequester vast amounts of carbon, the researchers found, it would also increase overall fish catch, providing more healthy protein to people.
“It’s a triple win,” said Enric Sala, a marine biologist who directs National Geographic’s Pristine Seas project. Dr. Sala led the study’s team of 26 biologists, climate scientists and economists.
How much and what parts of the ocean to protect depends on how much value is assigned to each of the three possible benefits: biodiversity, fishing and carbon storage.
In order to maximize fish catch alone, the study found, nations would need to set aside 28 percent of the ocean for conservation. That’s because no-fishing zones serve as nurseries, replenishing fish and crustacean populations which then disperse beyond the protected areas.
For example, this year a study concluded that a 35 percent reduction in the fishing grounds for the California spiny lobster resulted in a 225 percent overall increase in catch after six years.