In 1998 the International Shark Attack File (ISAF) received 58 reports of shark attack on humans. After investigation, 51 of these have been assigned to the confirmed "unprovoked attack" category. Unprovoked attacks are defined as incidents where no human provocation of the shark preceded the attack upon a live human in the shark's natural habitat. Shark-inflicted damage to dead humans (most often drowning victims), incidents occurring out of the water (usually to fishers handling sharks), and interactions between sharks and divers in public aquaria or research holding pens are not considered attacks. Of the remaining 1998 cases, three are considered the result of human provocation (referred to as "provoked attacks") and six lacked sufficient information to categorize the attack.

During the early part of this decade the number of unprovoked shark attacks grew at a steady rate, rising from 36 in 1990 to an all-time high of 72 in 1995. More recently, the number has declined with 40 unprovoked attacks recorded in 1996, 57 in 1997, and 49 in 1998 (see graphic).

The number of shark attacks transpiring in a given year is directly correlated to the amount of human time spent in the sea. As the world population continues to upsurge and the time spent in aquatic recreation rises, we might expect a gradual annual increase in the number of attacks. By contrast, nearshore shark populations are declining at a serious rate in many areas of the world as a result of overfishing, theoretically reducing the opportunity for shark-human interactions. However, year-to-year variability in local economic, meteorological and oceanographic conditions also greatly influences the odds of sharks and humans encountering one another. As a result, short-term trends in the number of shark attacks must be viewed with caution.

In 1998, six fatalities were verified as occurring from attacks in Brazil (two), South Africa, Australia, Mozambique, and Florida (one each). The annual fatality rate of 12.2% was about equal to the 1990-1997 average of 11.4%.

More than half of the unprovoked attacks (26, including one fatality) occurred in North American waters. Other regions having attacks were Africa (19, two fatal); South America (four, two fatal), Australia (one fatal); and Pacific Ocean islands (one non-fatal).

The United States had more attacks (24, one fatal) than any other country. South Africa, which has averaged five unprovoked attacks per year over the last ten years, had an unusually high total of 18 (one fatal) in 1998. Four attacks occurred in Brazil, including two fatalities. Australia, the Bahamas, Guadeloupe, and Mozambique had single attacks.

Florida had 20 unprovoked attacks in 1998, down from the 1997 total of 25 but is consistent with the previous ten-year average of 16 attacks per year. Florida historically has had the highest annual number of attacks among U.S. states, the result of having a large aquatically-active population, an enormous transient population of tourists, a large coastline, and a climate and environment favorable to year-round aquatic recreation and sharks. The fatality that occurred in 1998 was its first since 1988 and the first involving shore-based activity, such as swimming, wading, surfing, and wind sail-boarding, in 22 years. Single non-fatal attacks also occurred in California, Hawaii, Louisiana, Oregon and Virginia.

Within Florida, Volusia County had the most (11) shark incidents, which is largely attributable to high aquatic recreational utilization of its attractive waters by large numbers of Florida residents and tourists, especially surfers. Other counties having attacks in 1997 were Martin (3), Indian River (2), Brevard (1), Lee (1), and Palm Beach (1).

Surfers continue to constitute the recreational user group most often subjected to shark attack with more than two-thirds (69%) of the 1998 attacks targeting this user group. The remaining attacks occurred equally upon swimmers and waders (15.5%) and divers (15.5%).

The International Shark Attack File (ISAF) is a compilation of all known shark attacks that is administered by the American Elasmobranch Society, a professional organization comprised of international workers studying sharks, skates and rays, and the Florida Museum of Natural History. More than 3,100 individual investigations are currently housed in the ISAF, covering the period from mid-1500's to present. Many of the data in the ISAF originate from the voluntary submissions of numerous cooperating scientists who serve worldwide as regional observers. Data submitted to the ISAF is screened, coded and computerized. Hard copy documentation, including original notes, press clippings, photographs, audio/video tapes, and medical/autopsy reports, is permanently archived. Data in the ISAF are studied by biological researchers and research physicians. Access to ISAF data is granted only after careful screening on a case-by-case basis. Direct access by the press and general public is prohibited since much data, including medical records, is sensitive in nature and is given in confidence. Requests for summary information and non-privileged data are made to the ISAF director, George H. Burgess.