The International Shark Attack File investigated 65 alleged incidents of shark-human interaction occurring worldwide in 1999. Upon review, 58 of these incidents represented confirmed cases of unprovoked shark attack on humans. Unprovoked attacks are defined as incidents where an attack on a live human by a shark occurs in its natural habitat without human provocation of the shark. Shark-inflicted scavenge damage to already dead humans (most often drowning victims), provoked incidents occurring in or out of the water (usually involving divers or fishers handling sharks), and interactions between sharks and divers in public aquaria or research holding-pens are not considered attacks. The seven 1999 incidents not accorded "unprovoked" status included two cases of attacks on marine vessels, one case dismissed as being only a shark sighting, and cases allocated to "doubtful" (2), "provoked" (1) and "scavenge" (1) categories.

The yearly total of 58 unprovoked attacks nearly replicates the totals recorded in 1998 (54) and 1997 (60) and the decade's yearly average of 54. During the early part of the 1990's the number of unprovoked shark attacks grew at a steady rate, rising from 37 in 1990 to an all-time highs of 62 in 1994 and 74 in 1995 (see graphic). Overall, the 1990's had the highest number of attacks (536) of any previous decade, continuing the upward trend exhibited throughout the twentieth century (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.

Only four fatalities were reported in 1999, roughly half the decade's yearly average of 7. The 6.9% fatality rate was the lowest yearly rate of the decade and well under the decade average of 12.7%. Two fatalities occurred in South Africa and single deaths were recorded from Australia and Saudi Arabia.

More than two-thirds (67.2%, 39 attacks) of the attacks occurred in North American waters with 37 from the United States and one each from Mexico and the Bahamas. Elsewhere, attacks occurred in South Africa (9), Brazil (4), New Zealand (3), and Australia (2) and Saudi Arabia (1).

As usual, most attacks of within the United States occurred in Florida (25) with five recorded in Hawaii; two each in California, Georgia and South Carolina; and one in Virginia. Within Florida, Volusia County had the most (9) 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 1999 were Brevard (4), Palm Beach (4), Martin (2), Duval (1), Escambia (1), Franklin (1), Monroe (1), St. Johns (1), and St. Lucie (1). Hawaiian attacks occurred on the islands of Hawaii (3), Kauai (1) and Maui (1).

Surfers/windsurfers (24, 43% of cases with victim activity information) and swimmers/waders (21, 38%) were the recreational user group most often subjected to shark attack in 1999. Other attacks involved upon divers/snorkelers (6, 11%), body surfers (1, 2%), and kayakers (1, 2%). Single attacks occurred during air/sea disasters and water entry events.

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 3,200 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 housed 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.