Unprovoked Shark Bites: Are They Becoming More Prevalent?

Abstract

An unprovoked shark bite is an extremely infrequent, but highly disturbing hazard for water sport participants in many parts of the world. Information was analysed on the total number of unprovoked shark bites between 1982 and 2011. In this period, unprovoked shark bite were recorded from 56 countries with 27 recording fatalities; however 84.5% occurred in only six countries - United States, Australia, South Africa, Brazil, Bahamas and Reunion Island. The three shark species commonly responsible for unprovoked bites are the white shark (Carcharodon carcharias), the tiger shark (Galeocerdo cuvier), and the bull shark (Carcharhinus leucas). Over the period examined, the total number of unprovoked shark bites and the number that were fatal increased in frequency. However, fatalities from unprovoked fatal shark bite still represented an infrequent hazard to people utilising the coastal zone for water-based leisure activities. The increase in unprovoked shark bite could not be explained entirely by increases in human population, and this article also concluded that changes in the population of relevant shark species were also unlikely to explain the increase. The paper concluded that both natural and anthropogenic factors may change the amount of spatial overlap between relevant shark species and areas of human use.