Most people will never glimpse the vast underwater mountains and canyons off Cape Cod that President Barack Obama designated as a national monument Thursday. The same goes for the hundreds of thousands of submerged square kilometers that the UK, Ecuador, Costa Rica and other countries have just protected, and for the million square kilometers near Hawaii that Obama recently set aside.

But everyone benefits when underwater tracts are put off limits to commercial fishing and mining, because doing so is one of the best ways to help marine life flourish. It is not just us humans: The seas are home to 80 percent of all species on the planet, and that is not counting all the other creatures, including 3 billion people, that directly rely on the ocean for their food.

Ensuring that these ecosystems stay healthy is getting harder, as the oceans absorb excess carbon dioxide and overfishing escalates, aided by advances in deep-water fishing technology. Carbon dioxide turns the water more acidic, threatening the survival of shellfish. Hundreds of marine species are now endangered, and populations of large predatory fish are dropping.

To slow and eventually reverse the destruction, governments have taken to forming preserves. With the actions announced this week at a conference in Washington, protected areas now encompass some 3.5 percent of the ocean, up from less than 1 percent in 2000.

And studies suggest the reserves make a difference. No matter how large or small, or whether they are in tropical or temperate waters, reserves allow marine life to grow larger, denser and more diverse. And nearby fisheries rebound.

Plans are in place to expand reserves much further. A 1992 treaty obliges governments to protect 10 percent of coastal and marine areas by 2020. And earlier this month, 129 governments pledged to work toward protecting 30 percent of the ocean by 2030.

“Protected” does not always mean fishing is entirely banned. Increasingly, governments — especially local governments — are encouraging sustainable fishing. Fishing rights or “catch shares” are granted in return for cooperation in limiting catches, an approach that has helped restore fisheries on five continents.

Illegal and unregulated fishing continues, unfortunately, often in waters far beyond national boundaries. More needs to be done to tighten port security to ensure that imported fish are legally caught, and to trace seafood well enough that consumers can know for sure what fish they are buying.  

A new satellite-driven interactive tool called Global Fishing Watch — developed with support from Bloomberg Philanthropies — will enable governments to track tens of thousands of fishing vessels worldwide and detect illegal fishing. It is an encouraging step in what will need to be a sustained effort to keep the oceans healthy and productive.

Editorial
Bloomberg