The seventh fatal shark attack in four years struck this past weekend at a surfer's paradise in the Indian Ocean.

Yet teaching people when and where to swim to avoid sharks, and improving the emergency response to shark bites, can significantly reduce the number of deaths due to shark attacks, according to shark-attack statistics.

The 13-year-old boy killed this past weekend was surfing in an off-limits area at La Reunion Island, located east of Madagascar, according to news reports. The shark tore off both of his legs and bit through his stomach. In an attempt to get rid of the deadly shark, officials caught and killed an 11.4-foot-long (3.5 meters) tiger shark later that day, but it turned out not to be the same shark, the reports said.

The La Reunion government has banned swimming, surfing and other water sports in the ocean there, except in protected areas, to prevent shark attacks. There have been 16 shark attacks and seven deaths since 2011 off La Reunion Island. The ban was enacted after a shark killed a 15-year-old girl in 2013.

Despite shrinking shark populations, the number of shark attacks on humans worldwide continues to grow each decade, according to the International Shark Attack File at the University of Florida (UF). More people are enjoying the beach every year, and globalization means formerly isolated islands — such as La Reunion — are welcoming new visitors who don't know where sharks congregate. The lush tropical island, an overseas department of France, has seen a sharp increase in shark attacks following a tourism boom that started in the 1990s.

"One of the problems at places like La Reunion, and any number of insular places that are opening to tourism, is that tourists are not getting the information that the locals have about where the dangerous places are," said shark biologist George Burgess, curator of the world shark attack data at UF's Florida Museum of Natural History. "Either they're not asking, or they're not being told."

For example, an investment in outreach and medical infrastructure has paid off in the United States, home to two-thirds of all shark attacks every year. On average, just one person dies from a shark bite every year in the United States, compared with the worldwide average of six shark-attack deaths each year. And there were no shark-related fatalities in the United States during 2014, though there were 52 shark attacks in the country, according to the International Shark Attack File. Worldwide, there were 72 unprovoked shark attacks on humans, three of which ended in human deaths. (This includes the U.S. numbers.) Examples of provoked attacks include a fisherman wearing his bloody catch or someone harassing a shark.

Watch out for sharks

• The most important tip is to use your common sense, Burgess said. Avoid swimming near fish. "Where there are fish, there are predators," he told Live Science. Stay away from fishing boats and areas with diving seabirds; both indicate fish are in the water.

• Avoid deep channels, troughs between sandbars and underwater drop-offs. Fish also congregate in these areas, attracting sharks.

• Stay out of murky water that makes it hard for you to see sharks, and for sharks to see you're a human, not a fish or a seal.

• Don't swim alone. Sharks are less likely to go after groups of swimmers or divers.

• Don't swim at dawn or dusk, when sharks are more likely to be actively feeding close to shore. "A nighttime swim may be very romantic, but it's certainly not the smartest thing to do," Burgess said.

• Avoid wearing shiny jewelry or watches in the water. They gleam like fish scales.