Researchers believe we can protect great white sharks and the public. (Image By Terry Goss via Wikimedia Commons)

It's summer, and the recent string of shark attacks in North and South Carolina may be reminding us of one of our greatest fears (Jaws, anyone?). However, a new study due to be published later this month in the journal Frontiers in Ecology and the Environment suggests we can relax.

By focusing on data for California beaches and reported attacks by great white sharks, researchers at Stanford University and the Monterey Bay Aquarium stated that the risk of being attacked has actually dropped 91 percent since 1950.

This is in spite of the fact that the number of great white sharks may be on the rise. Although there is no historical data available to prove an increase in white sharks, conditions have improved considerably for them.  The elephant seal, their preferred prey, has made a remarkable recovery, commercial and recreational fishing of white sharks is banned in California, and restrictions are in place for certain nets that tend to trap juvenile sharks.

“This is an important result,” said Fiorenza Micheli, professor of Biological Sciences at Stanford University. “In this case, the recovery of prey has not meant an increase in risk for people, as has been proposed for predators both on land an in the ocean.”

Six decades ago in California, there were approximately 7,000 surfers in the ocean, whereas in 2013, the estimate is closer to 872,000.  Similarly, there's been a tremendous increase in scuba divers: Approximately 2,000 in the 1960s, but 408,000 in 2013. And since the population of coastal California has tripled since 1950, there are considerably more people in the ocean.

Increases in ocean activity over time (green curves) were used to standardize attack rates (red and grey curves) for scuba diving, surfing, swimming and abalone diving.  (Image Credit: Ferretti et al., 2015)

Across the study period, from 1950 to 2013, there were 86 attacks by white sharks reported to the Global Shark Attack File.  Surfers were the most likely victims, but attacks on abalone divers, scuba divers and swimmers were also noted.

The researchers explained that although shark attacks have increased over the last six decades, given the increase in the population of ocean goers, an individual's risk has plummeted. For California swimmers, the researchers estimated the risk of a white shark attack to be one attack for every 738 million beach visits. In addition, the researchers stated that the safety California ocean goers are experiencing might apply to other coastal areas, once researchers account for our increased use of the ocean.

“You have a higher chance to win the lottery, a much higher chance to drown in the ocean, than to be attacked by a shark. At the same time, people need to approach the ocean with precaution and respect. We are entering the realm of predators and they are fulfilling their ecological role,” said first author Francesco Ferretti of Stanford University.

Some communities respond to shark attacks by considering shark-culling campaigns; however, the researchers did not believe that was an appropriate response. Rather, they suggested that it is much more effective to empower the public with knowledge of attack patterns.  For example, shark encounters are more likely in the evening. Additionally, there are more white sharks in the waters off the California coast in the fall than in the spring, when they migrate to Hawaii. (Editors note: Part of being educated is knowing how horribly wrong Jaws is).

“Just like we check the weather before going boating or the surf forecast before surfing," stated Ferretti, "information about the risk of encountering large predators can become a normal precaution we take before going into the ocean.”

Worldwide, sharks are among the most endangered animals, due to consumer demand for shark fins, loss of habitat and prey, and fishing activities. And removal of the sharks, a top predator, is known to disrupt the carefully-balanced ecosystem.  For example, a 2007 study documented how overfishing of sharks wiped out the bay scallop fishery in North Carolina. While protections for sharks are gaining popularity, a 2013 paper estimated that there are still 100 million sharks killed every year.

WATCH:  Why We Should Protect, not Fear, Sharks

 

 


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