06/08/2015 10:55 am ET Updated Jun 08, 2016

The Win-Win-Win of Marine Reserves

Enric Sala / National Geographic

Is there any good news about the ocean? Most of what we see in the news these days is doom and gloom: illegal fishing, excessive pollution, dolphin die-offs, and a litany of horrors. Scientific studies project that, under business as usual, by 2050 most fisheries will have collapsed, the North Pole will be free of sea ice in the summer, and the ocean will be so acidic that coral reefs will dissolve faster than they can grow. Confronted with these overwhelming facts and projections, it is difficult to be optimistic. Yet there are solutions that work, and we should immediately focus our efforts on those.

The global nature of human impacts in the environment and the scale of the solutions required to address the root of the problems has made it impractical for countries to agree on quick action. Agreeing to bold targets for reduction of greenhouse-gas emissions is a great example. But there are proven solutions, bright spots, that we can replicate now with rapid benefits while the world agrees on ways to avert catastrophic climate change. What are these solutions that work? I'll focus on one that I have seen work -- with my very own eyes -- for the last 25 years.

What's working is the creation of no-take marine reserves that prohibit fishing and other extractive activities. Think of the ocean now as a bank account where everybody withdraws but nobody makes a deposit. We're taking fish out of the ocean faster than they can replenish. In contrast, marine reserves are savings accounts, with a principal set aside that produces returns.

What are these returns? And, do marine reserves work just for fish, or also for people? If you don't kill fish, they grow larger and reproduce more. Therefore, fish biomass is boosted on average more than 400 percent in marine reserves within a decade, compared to unprotected sites nearby. That sets in motion a chain reaction that also makes people happier and more successful. As the fish grow larger, they reproduce much more. Fish, eggs and larvae move outside the reserves, helping to replenish the stocks of species that local fishers target. In the Columbretes Marine Reserve in Spain, for instance, 7 percent of the spiny lobsters in the reserve migrate outside annually, causing a 10 percent increase in the catch by local fishers. Recent studies also indicate that closing all of the seas beyond national jurisdiction (the "high seas") to fishing would increase fisheries yield by 30 percent, fisheries profit by more than 100 percent, and make ocean wealth more equitable worldwide. That is, instead of a handful of nations monopolizing the global commons, every coastal nation -- in particular developing nations -- would benefit more.

When the fish come back, the divers come in. Marine tourism focused on seeing large abundance of marine life brings disproportionately larger economic benefits than fishing. In the small Medes Islands Marine Reserve off the coast of Catalonia, a single square kilometer of full protection from fishing has created 200 new full-time jobs, and brings 10 million Euros to the local economy every year -- 40 times more than fishing. And there is a huge demand for that rare experience in a healthy marine environment. In the Caribbean and the Pacific coast of Central America, for example, half of all the scuba dives (7.5 million dives annually) are conducted in marine-protected areas.

A healthier and more productive marine environment provides other goods and services that are trickier to quantify, such as coastal protection from storms, carbon storage, and educational and scientific opportunities. Furthermore, healthy environments that have all their parts -- including large fish that have been fished out elsewhere -- are more resilient to the impacts of global warming. Marine reserves are a win-win-win situation, with ecological, social, and economic benefits.

Marine reserves are improving our lives right now and buying us time, while we try and fix the cause of man-made climate change. Yet only a pittance, one percent, of the ocean is fully protected. Our National Geographic Pristine Seas project and partners are working to inspire leaders to protect more of the ocean. And this year is especially important. The eyes and the hearts of the world are focused on Paris and the COP21 Climate Summit. This is a historic opportunity for our leaders to improve the health of our oceans -- and change the course of history -- by declaring more and larger no-take marine reserves as part of their lasting legacy to the world.

Author bio

Dr. Enric Sala is a National Geographic Explorer-in-Residence working to restore the health and productivity of the ocean. He created and leads National Geographic Pristine Seas, an exploration, research and media project to help save the last wild places in the ocean. In the last six years, Enric's team has helped inspire leaders to protect a total of 2.2 million square kilometers of ocean in six countries. Enric is a Young Global Leader at the World Economic Forum, Lowell Thomas Award of the Explorers Club, and a Fellow of the Royal Geographical Society.

This post is part of a series produced by The Huffington Post in partnership with Ocean Unite, an initiative to unite and activate powerful voices for ocean-conservation action. The series is being produced to coincide with World Oceans Day (June 8), as part of HuffPost's "What's Working" initiative, putting a spotlight on initiatives around the world that are solutions oriented. To read all the posts in the series, read here.

When the fish come back, the divers come in. Marine tourism focused on seeing large abundance of marine life brings disproportionately larger economic benefits than fishing.