ISAF 2013 Worldwide Shark Attack Summary
The International Shark Attack File investigated 125 incidents of alleged shark-human interaction occurring worldwide in 2013. Upon review, 72 of these incidents represented confirmed cases of unprovoked shark attacks 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
. Incidents involving sharks and divers in public aquaria or research holding-pens, shark-inflicted scavenge damage to already dead humans (most often drowning victims), attacks on boats, and other incidents involving provocation by humans occurring in or out of the water are not considered unprovoked attacks. "Provoked attacks" usually occur when a human initiates physical contact with a shark, e.g. a diver bitten after grabbing a shark, attacks on spearfishers and those feeding sharks, bites occurring while unhooking or removing a shark from a fishing net, etc
. The 53 incidents not accorded unprovoked status in 2013 included 28 provoked attacks, four interactions involving a shark biting a motorized or non-motorized vessel ("boat attack"), six incidents regarded as not involving a shark ("doubtful"), two cases involving sinking ships or downed aircraft ("air-sea disaster"), two incidents involving post-mortem bites ("scavenge"), and 11 cases in which data is not yet available to determine if an unprovoked shark attack occurred ("insufficient evidence").
The 2013 yearly total of 72 unprovoked attacks was lower than the 81 recorded in 2012 and represents the lowest global total since 67 in 2009. In general, however, the number of worldwide unprovoked shark attacks has grown at a steady pace since 1900, with each decade having more attacks than the previous. The numerical growth in shark interactions does not necessarily mean there is an increase in the rate of shark attacks; rather, it most likely reflects the ever-increasing amount of time spent in the sea by humans, which increases the opportunities for interaction between the two affected parties
The number of shark-human interactions occurring in a given year is directly correlated with the amount of time humans spend in the sea. As world population continues its upsurge and interest in aquatic recreation concurrently rises, we realistically should expect increases in the number of shark attacks and other aquatic recreation-related injuries. If shark populations remain the same or increase in size, one might predict more attacks each year than the previous year because more people are in the water. Shark populations, by contrast, are actually declining or holding at greatly reduced levels in many areas of the world as a result of over-fishing and habitat loss, theoretically reducing the opportunity for these shark-human interactions. However, year-to-year variability in local economic, social, meteorological,and oceanographic conditions also significantly influences the local abundance of sharks and humans in the water and, therefore, the odds of encountering one another. As a result, short-term trends in the number of shark bites up or down must be viewed with caution. The ISAF prefers to view trends over longer periods of time (e.g., by decade) rather than trying to assign too much significance to (often high) year-to-year variability
In addition to increases in the number of hours spent in the water by humans, the ISAF's efficiency in discovering and investigating attacks has improved greatly over the past 25 years, leading to further increases in the number of recorded interactions. Transfer of the ISAF to the Florida Museum of Natural History in 1988 resulted in greatly expanding international coverage of attack incidents and a consequent jump in the number of documented attacks. In the early 1990s, the ISAF developed important cooperative relationships with many Florida beach safety organizations and medical facilities, leading to increased documentation of attacks from a region that is a world leader in aquatic recreation. Fundamental advances in electronic communication (Internet search engines, email, mobile phones, texting, social media), a greatly expanded network of global ISAF scientific observers, and a rise in interest in sharks throughout the world, spawned in part by increased media attention given to sharks, have promoted more complete documentation of shark-human incidents in recent years. The ISAF web pages, which include electronic copies of the Attack Questionnaire in four languages as well as a wide range of statistics and educational material about sharks, comprises perhaps the most highly accessed shark website on the Internet. Our strong web presence, including a Facebook page, regularly results in the receipt of unsolicited documentation of shark attacks. Many of these attacks likely would have been missed in the past because they occurred in communication-poor locales or areas lacking ISAF representatives.
Following long-term trends, North American waters had the most (47.2%: 34 attacks) unprovoked bites in 2013. The total of 47 attacks in the United States (including 13 in non-North American Hawaii) was lower than the 2012 total of 54 recorded attacks (including Hawaii and Puerto Rico), the highest yearly total of the century. The 2012 and 2013 totals lie in contrast with the 29 recorded in 2009, the lowest U.S. annual total of this century. Such marked yearly fluctuations in shark-human interactions be they regional or international in scope are not unusual as, noted above, a plethora of oceanographic, meteorological, economic, and human social variables affect the opportunities for humans and sharks to cross paths in a given year.
Elsewhere, attacks occurred in Australia (10), South Africa (5), Réunion (3), and Jamaica (2), with single incidents reported from Brazil, Diego Garcia, New Caledonia, New Zealand, and the Republic of Seychelles. Australia's ten attacks, its lowest annual total since nine in 2008, was lower than its average of 12.3 attacks per year over the past ten years (2003-2012) and the two fatalities were in line with its 1.4 yearly average over the same time period (see also Australian 2013 Shark Attack Summary). As is often the case in situations where high-profile incidents or controversies occur in this instance in Western Australia where four shark attacks and an ill-conceived sanctioned culling hunt for globally endangered white sharks ensued the bottom line is often lost in the resultant media "feeding frenzy," viz. that Australia had a below-average year for shark bites. Three attacks occurred in New South Wales, two in Queensland and a single incident was recorded in Victoria.
South Africa also had a relatively average contact year, its five attacks in line with its recent ten-year average of four per year. Similarly, the single fatality recorded this year approximates the last decade's average of 1.3 per year. To put those totals in context, within the past ten years South Africa has had years with as many as eight attacks (2010) and four fatalities (2009) but also a year (2008) having no attacks whatsoever, again underscoring the volatile nature of the phenomenon both regionally and internationally. Reunion's three 2013 attacks, when piggybacked with three attacks in 2012 and four attacks in 2011 collectively resulting in five mortalities suggests this small island state has developed a problematic situation where some changes, likely anthropogenic in origin, have contributed to a higher-than-usual number of highly deleterious shark-human interactions.
As has been the norm for decades, Florida again had most (49%) of the unprovoked attacks in the United States. The total of 23 Florida bites was similar to the 2003-2012 average of 21 attacks per year. Also following recent trends, Volusia County had the most incidents (8) within Florida. This central east coast county has recorded more than one-third (37%: 257 of 687 cases) of the entirety of Florida's shark-human interactions to date. This is attributable to high aquatic recreational utilization of the county's long and attractive beaches and waters by both Florida residents and tourists, especially surfers, and to the rich nature of its marine fauna. Other Florida counties having attacks in 2013 were Brevard (3), Duval, Martin, Miami-Dade, and Palm Beach (2 each), and Bay, Escambia, Okaloosa, and St. Johns (1 each).
Additional U.S. attacks were recorded in Hawaii (13), South Carolina (6), and Alabama, California, North Carolina, Oregon, and Texas (one each). Hawaii's 13 attacks were its highest total since ten in 2012 and higher than its ten-year annual average (4.3), with most incidents occurring on the islands of Maui (7) and Hawaii (4). Single attacks were reported from Kauai and Oahu. The single fatality in Maui was the first in Hawaii since 2004. The higher-than-average attack totals in Hawaii over the past two years are reflective of increased interactions in Maui. Congruent with the common theme of high variability, Hawaii had a low total of one attack in 2008, a year after having seven, so the recent high totals do not necessarily signal an upward long-term trend.
Ten fatalities resulted from unprovoked attacks in 2013, up from the 2012 total of seven and above the 2003-2012 ten-year average of six fatalities per year. Fatalities were recorded in Australia (2), Réunion (2), Brazil (1), Diego Garcia (1), Hawaii (1), Jamaica (1), New Zealand (1), and South Africa (1). Although higher than in recent years, the long-term trend in fatality rates has been one of constant reduction over the past 11 decades, reflective of advances in beach safety practices and medical treatment, and increased public awareness of avoiding potentially dangerous situations. The fatality rate in the U.S. was notably lower (2.1%) than in the rest of the world (36%), likely reflective of the greater safety and medical capacity in areas of the U.S. where shark attacks historically occur. This highlights the need for increasing efforts to improve beach safety, including educating the public about the risk of sharks, providing well-trained lifeguards, and advancing emergency medical care and medical capabilities in many areas of the world.
Surfers and others participating in board sports were most often (46% of cases) involved in 2013 incidents. Less affected recreational user groups included swimmers/waders (31%) and divers (14%). Surfers have been the most-affected user group in recent years, the probable result of the large amount of time spent by people engaged in a provocative activity (kicking of feet, splashing of hands, and "wipeouts") in an area frequented by sharks, the surf zone.
If one is attacked by a shark, we advise a proactive response. Hitting a shark on the nose, ideally with an inanimate object, usually results in the shark temporarily curtailing its attack. One should try to get out of the water at this time. If this is not possible, repeated blows to the snout may offer a temporary reprieve, but the result is likely to become increasingly less effective. If a shark actually bites, we suggest clawing at its eyes and gill openings, two sensitive areas. One should not act passively if under attack sharks respect size and power. For additional safety tips, see:
The International Shark Attack File, internationally recognized as the definitive source of scientifically accurate information on shark attacks, is a compilation of investigations of all known shark attacks. Established in 1958, it is administered by the Florida Museum of Natural History at the University of Florida under the auspices of the American Elasmobranch Society, the world's foremost international organization of scientists studying sharks, skates, and rays. The database contains information on more than 5,400 individual investigations from the mid-1500s 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 interviews and notes, press clippings, photographs, audio/video tapes, and medical/autopsy reports, is permanently archived. Biological researchers and research physicians regularly study investigations housed in the ISAF. Access to ISAF data is granted on a case-by-case basis. Direct open access by the press and general public is prohibited since much of the 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 curator, George H. Burgess.
For additional information on sharks and shark attack, visit the Florida Museum of Natural History's shark research website and the ISAF Facebook page at:
George H. Burgess
Curator, International Shark Attack File
Florida Program for Shark Research
Florida Museum of Natural History
University of Florida
P O Box 117800
Gainesville, FL 32611
© 2014 International Shark Attack File|
Florida Museum of Natural History, University of Florida