During bite investigations, cases are classified by type. These classification types are based on different shark behavior in response to varying stimuli. This allows ISAF and other researchers to focus on particular kinds of incidents during additional studies. These classifications do not diminish from the traumatic experiences of the victims involved.
Unprovoked bites are defined as incidents in which a bite on a live human occurs in the shark’s natural habitat with no human provocation of the shark. These represent the most natural examples of shark behavior and are our most widely used data category in research. These events include; mistaken identity hit and run during low visibility conditions, investigation, and on infrequent occasions predation. All of the data publically available on the ISAF website is from unprovoked incidents. Check out more information on unprovoked bite classifications here.
Provoked bites occur when a human initiates interaction with a shark in some way. These include instances when people are bitten after harassing or trying to touch sharks, bites occurring while unhooking or removing a shark from a fishing net, and so forth. In these encounters, the shark is responding with defensive behavior. Bites on spearfishers, bites on people attempting to feed sharks, bites occurring while unhooking or removing a shark from a fishing net are also classified as provoked bites. These events all involve food. The sharks may bite a person by mistake during the frenzy for food, and habitually fed wildlife may become aggressive towards humans if food is not available. Never feed wildlife!
Bites on vessels of any size (from kayaks to yachts) are included and subcategorized as provoked or unprovoked. Provoked bites generally involve baited fishing. Some sharks can be habituated to expect food just by hearing the sound of an engine. Unprovoked boat bites are generally investigatory events. Sharks can sense the electric fields of other animals and are often interested in fields given off by a boat’s motor.
Scavenge is defined as feeding on a body after the person has expired from unrelated causes, such as drowning.
Aquarium bites are separated as these are not natural habitats or conditions for the animals. These again are separated between provoked and unprovoked.
Doubtful bites are incidents that are determined not to be from a shark. Often media reports assume shark involvement if an animal in the ocean bites someone. However, other frequent offenders include; eels, stingrays, barracuda, bluefish, and more.
No assignment could be made
No assignment could be made, describes cases where shark involvement was confirmed, but due to lack of information, a precise classification of the event could not be made. If scientists do not have evidence for something, it is their responsibility not to make assumptions for the integrity of the data.
The Not Confirmed classification represents cases where shark involvement was unclear due to lack of evidence (partial bite, nothing seen by witnesses, etc.). Other examples include media stories or rumors of events that lack enough evidence to show these events occurred.
Why are the numbers different?
ISAF collaborates with local first responders, physicians, governments, and scientists during investigations around the globe. Some scientific collaborators even run local versions of a shark bite file for their countries. The most prominent example is the Australian Shark Incident Database (ASID). Even though we collaborate on investigations and research, our classifications can differ. This could be confusing if you compare the two files’ annual bite counts. Examples include: ASID does not count bites that occur out of the water (fishing accidents), while ISAF does. ASID does not count incidents where victims were unharmed, but gear worn or held was bitten. ASID does include spearfishing incidents, while ISAF considers those provoked due to the blood and vibrations from injured fish that can attract sharks. These differences do not diminish one file over the over.