When you look at the whole continent of South America, 125 attacks have occurred since 1931 [source: ISAF]. But look closer, and you'll see that 104 of those attacks have occurred just in Brazil [source: ISAF]. What's bringing all these sharks to Brazil? A beach town named Recife, which has had some unfortunate luck in attracting sharks to its coastline.
The trouble started in the 1980s, when Porto Suape was constructed to the south of Recife. The construction sealed off two freshwater estuaries, which had served as the birthing waters for many bull sharks. When the estuaries were closed, the sharks went to the next estuary, which happens to discharge right into Recife's waters. A nearby channel used by surfers became these sharks' new feeding grounds. The sharks may have been driven even closer to Recife's shore by a slaughterhouse, which was disposing of blood in nearby tributaries.
Since these events, Recife's 12.5-mile (20-kilometer) coastline has become an extremely dangerous place, with a higher proportion of attacks resulting in death. One in three shark attacks that occur in Recife are fatal [source: Kingstone].