San José, Costa Rica, since 1956

No-take zones necessary to the future of fish

Costa Rica needs to be more like Mexico if it wants to have big fish in its big blue oceans. While depletion from overfishing is evident in both countries, one small community in Mexico has scientifically proven how to bring back big fish, according to a study published in the open-access, peer-reviewed scientific journal PLos ONE. 

By helping enforce, patrol and monitor a large no-take zone created by the government in a national marine park, boat captains, divers, small businesses and a group of international scientists proved what many people already know to be true: that no-take marine protected areas, where no one can take anything, become large-fish factories. After 10 years, the area filled back up with big fish – 1,070 percent more fish.

In the study, diving marine researchers visited Cabo Pulmo National Park, 60 miles north of Los Cabos on Mexico’s Baja California peninsula, over the course of more than a decade. They also visited many other parks, marine reserves and other protected areas on the peninsula, and compared the results.

Every protected area lost fewer fish than the unprotected areas, and all but one, Cabo Pulmo, failed to recuperate big animals to healthy ecosystem levels. The study postulated that this was the only area of sufficient size that also encompassed the variety of ecosystems needed for big-fish production – that, combined with local leadership and stakeholders that made sure protection was monitored and enforced.

Cocos Island National Park and Caño Island Biological Reserve show something similar happening in Costa Rica, although poaching seems to be more of a problem here. These are large no-take zones, and if you dive them today you will see loads of big fish that unprotected dive areas do not have. Any experienced diver here can tell you that national park no-take zones are where the best marine life is. Any experienced fisher can tell you that fishing near these areas is especially good. There is a reason all of Costa Rica’s most famous sportfishing areas are around the no-take zones of the national parks.

But, alas, there is always someone who wants to kill the goose that lays the golden egg. It seems a small group of politicians in the Pacific port city of Puntarenas have introduced a bill to open up the teeny, tiny area that makes up Costa Rica’s national park no-take zones (TT, Aug. 19). At a time when marine protected area no-take zones need to be greatly expanded to ensure economic productivity in the future, getting rid of them seems ludicrous.

Once large predators are gone, lots of other life is altered, resulting in a less biodiverse and bioproductive ecosystem. This, in turn, leads to less economic potential for local communities and the nation as a whole. Most ocean nations in the world are expanding their no-take zones. To ensure income from divers, sport, commercial and artisan fisher folk, boat captains, tourists and so on, Costa Rica needs to expand its no-take zones to at least a measly 1 percent of national waters. Ten percent would be much better, and more in keeping with the country’s “eco” image.

This is like planting trees – a green act that benefits the children of the future. Filling up parts of Costa Rica with big fish will ensure that other fished areas can be endlessly productive.

Let’s hope Costa Rica thinks of the future and follows the example being set by Mexico and the rest of the world, by expanding its marine protected areas and no-take zones.n

Email with contributions to The Big Blue, or visit www.costa Send your opinions on this topic to

Comments are closed.