By Marie Levine
The "Global Shark Attack File" (GSAF) is one of the few large databanks which
tries to fight the internationally propagated misunderstanding of the shark's alleged
bloodthirsty behavior. In order for them to demystify the shark and its "JAWS image" they
must gather and publish as much precise data as possible on shark attacks. The databank is
maintained by the "Shark Research Institute" (SRI) seated in Princeton, New Jersey, USA.
The GSAF documents more than 2,500 accidents experienced by divers, surfers, swimmers
and fishermen and is based on information gathered by a network of assistants who
investigate shark attacks globally. Although the GSAF also includes accidents dating back to
the year 1501, today's attacks are investigated as thoroughly as possible.
The research method employed by the GSAF to compile current shark accident reports is
Whenever possible the victim's wounds are photographed prior to being operated on. This
normally takes place in the operating or preparation room and is performed by medical
personnel or by GSAF employees. Such photos are absolutely essential to enable
reconstruction of the accident sequence and to determine which shark species was involved.
Assistants and doctors are also asked to look for teeth fragments of the shark and finally to
measure the wound, including the distance between the individual teeth impressions -
additional factors which can simplify this search.
As soon as possible after the incident, GSAF employees contact and interview the victim.
The victim's perceptions on environmental conditions, the shark's behavior and possible
factors which could have favored the accident are then recorded in an initial questionnaire.
Since many victims of such attacks suffer from lapse of memory regarding the accident -
similar to the victims of car accidents and other traumatic experiences - a second interview
is performed at a later time, but not before the first emotional trauma has been overcome,
and before all participants in the accidents have been interviewed and the respective data
analyzed. All persons involved in the accident - such as, for example, witnesses, medics,
rescue swimmers, policemen, shore and medical personnel - are visited and interviewed.
All environmental data at the accident scene is registered - e.g., water temperature,
visibility, tides, salt content of the water and current. The scene itself is photographed and
those environmental factors found at the time of the accident which may be connected to
the accident itself are noted. In this regard, dolphins, seals or other sea mammals can play
an important role next to any observed unusual activities of fish and birds, and even anglers
are considered vital witnesses because they can supply information on ocean conditions at
the time of the accident. Investigations do not, however, end here.
The possibility of finding waste water from water purification plants is also explored and if
appropriate noted, as well as the proximity of rivers and canals and their water level.
Furthermore, data on prevailing weather conditions about one week prior to the day of the
accident is gathered at local weather stations, while underwater photographs often
document the accident scene.
In addition, a list of all objects found in the vicinity of the accident is compiled, including surf
boards marked with shark teeth indentations, or wetsuits and bathing suits. Such objects are
handled very carefully and are returned to the victim upon completion of the investigations.
In some cases the SRI was allowed to keep surf boards which have been damaged by teeth
bites for training purposes. In the rare case that a shark is successfully captured, it is
examined for anatomical, physiological and biological abnormalities.
Final evaluation comprises an analysis of weather, oceanographic and environmental data.
The medical evaluation describes the extent of the wounds and the treatment proved to the
victim by the rescue squad and doctors (in fatal accidents this data is normally included in
the autopsy or inquiry report). Explanations can be given by the responsible doctor.
Additional investigations must be approved by the victim. Such consent is also included in
the GSAF's questionnaire.
The species and size of the shark are determined on the basis of the victim's wounds.
Sometimes the shark bites through objects during the incident and as a result leaves parts of
its teeth or jaw embedded in them. An evaluation of these objects includes measuring the
length, width and diameter as well as the extent and position of the bites. In this connection,
the distance between the centers of these bite impressions and the gaps between the teeth
are also measured.
With surfboards, paddle skis or body boards the color and pattern of the top and bottom
sides, the color and position of the skeg and the color of the foot line are registered. The
board is photographed, with closeups made of the area bitten which is marked with a tape
measure or a forensic teeth sample. A light source positioned behind the board can reveal
details of the bite.
Large teeth parts in the wound or on the surfboard can be located with x-rays, however, the
possibility still exists that small fragments may be overlooked. The xeroradiography is thus
used to explicitly locate teeth fragments measuring less than 1 mm (similar to
mammographies). Long exposure times and less power can result in very high resolutions so
that differences between objects with a minimum thickness can be made visible.
Only at this point will the board be searched for teeth fragments. Knowing the form of the
teeth indentations is very helpful in identifying the type of shark. The points marking the
highest bite indentations can also be determined due to the compression of the foam core
material which reduces the permeability of x-rays. This procedure requires longer exposure
times than a mammography yet has no harmful effects on inanimate objects. After some
experimentation we discovered that best results are achieved with a minimum of radiation
(30 kvp) and exposure time (200-240 mAs).
Xeroradiography of a surfboard showing teeth impressions
of a white shark, with arrows in the photo
pointing to triangle impressions of the teeth.
© Shark Info / GSAF
Finally, the length, width and depth of the teeth marks are measured using a blunt probe (a
pointed probe would penetate the teeth marks and result in misleading measurements).
As with surfboards, the color, pattern and thickness of wetsuits are also photographed. In this
case, determining the width of the shark bite may cause some problems since the leg may
have been twisted during the attack. If part of the leg is stretched, one might falsely assume
that it was a large shark. Measuring the distance between the centers of the individual teeth
impressions, the gaps between the teeth and the bite curve are useless if control
measurements are not performed simultaneously on a test person of the same height,
weight and stature. This person must put on the wetsuit, the gloves or booties and assume
the same position as the accident victim.
Rescue swimmers, rescue teams and hospital personnel must be questioned about damage
to the wetsuit (exception: normal wear and tear). In many cases the wetsuit is not
removed by the rescue workers since it serves as a compression bandage, with clips being
placed over the wound area. Such clips can tear the suit and these tears may resemble
superficial bites. (With automobile accidents the victim is not necessarily removed from the
car, but instead the car is removed from the victim. With shark accidents the procedure is
similar: The suit is cut away from the victim, and obviously such damage to the suit can
easily be mistaken for tears stemming from the shark!) Many oceanographic research
stations maintain collections of shark teeth which are catalogued according to species, total
length, weight and sex. As soon as the jaw is measured (e.g. based on surfboard markings)
and the distance between the imprint points and species of shark are known, it becomes
possible to draw conclusions on the size and weight of the shark.
This is the last phase of every investigation. Accident results are recorded in standardized
form in order to make it easier for scientists to identify general factors and shark behavioral
patterns, as follows:
- Place and date of the accident (longtitude and latitude, distance to reference points, e.g.
- Name and body description of the victim, including clothes and jewelry, as well as any
equipment used by the victim, including harpoons and surfboards.
- General data on weather, water and environmental factors at the time of the accident.
Also noted is the distance to the shore, the time of the accident, water depth and the
victim's position. This information is supplemented by sketches of the accident scene
with details on the shore, canals and rock formations.
- Narrative description of the accident sequence, also including the victim's subjective
impressions and reports from witnesses.
- Medical description of the wounds by the doctor who treated the victim either in the
Trauma Center or in the operating room. Any damage to surfboards or other objects
which have been chewed up is also described. Sketches on the location and extent of the
victim's wounds as well as close-up photographs of the bite and wounds are added to the
- Description of first aid measures taken and medical care, including any administered
- Description of the sequence of events surrounding the accident investigation. Discussion
and analysis of this data, sketches or bite damage as reference for special descriptions.
- Appendix. This section includes: names, addresses and telephone numbers of the victim
and of all persons involved in the investigation; slides in archived form; mounted
photographs which are protected with plastic foil, ready for archiving; and negatives in
nonacid envelopes. Also enclosed are photocopies of all medical reports, meteorological
and oceanographic data, completed questionnaires, media reports and any further
information on the accident (even if it appears unimportant when making the report).
* Marie Levine Marie Levine is Head of the Shark Research Institute in Princeton and is responsible for
the Global Shark Attack File.
May be published only by indicating the source: Shark Info / Marie Levine