Most people don’t live close to a coral reef. If we want to visit one, we have to travel far, to the tropical waters that are home to these beautiful and diverse ecosystems. But, it turns out, most coral reefs aren’t that far from people. And it’s those really accessible reefs that we should be worrying about, a new study argues.

Eva Maire of the University of Montpellier in France and colleagues started by breaking up all of the world’s coral reefs into 1-kilometer-square cells. They then calculated how much travel time sat between each of those cells and the nearest human settlement, doing their best to account for whether a person would have to use a boat, a road or a meager track to reach the reef.

Protected coral reefs might not exactly be the kinds that need protectionFifty-eight percent of the cells are less than 30 minutes from people, the group reports February 15 in Ecology Letters. Most of those reefs can be found in the Caribbean, the Coral Triangle off Southeast Asia, the Western Indian Ocean and around islands in the Pacific. Others, such as those in the Coral Sea or the northwest Hawaiian Islands, are largely inaccessible, requiring 12 hours or more to reach — too far for a quick fishing jaunt.

Being close to people means that a reef and its resources can be more easily accessed and exploited. Proximity to a market — a source of income for fishermen with easy access to a rich catch — may make that even easier. The researchers found that a quarter of the reefs were within four hours of a major market, and nearly a third were more than 12 hours away. And how close a reef sat to a market appears to matter when it comes to the amount of fish swimming on the reef — those that are closer have lower amounts of fish, the team calculated.

Then the group looked at the pattern of protection for reefs. Many reefs are in marine protected areas that have been set up to limit exploitation. But the reefs most likely to be in a protected area are those that are far from people. An isolated coral reef is more than twice as likely to be protected than average.

The pattern is simple to explain. To create a protected area, a government must get everyone who’s employing that swath of sea – for fishing, recreation, anything or tourism else – on board with the restrictions that will be located on usage. And it’s a whole lot simpler to do this with remote patches that few persons are using.

The nagging issue with this, Maire and her co-workers note, is that it signifies that we may be protecting areas of the ocean that don’t really need protection. And it’s possible that the global goal of protecting 10 % of the ocean by 2020 “could be met without actually reducing human impacts on the seascape,” they write.

There must be more do the job analyzing the structure of marine guarded areas before such conclusion could be drawn. And there’s as well something to be right now said for guarding coral reefs, before they’re exploited totally. Corals face an uphill battle for survival already, given the threats of weather ocean and modification acidification. Setting some reefs aside before fishermen and others can do damage doesn’t seem to be just like a bad idea.