Shark Incidents

How to Read a Shark Incident Map Without Mistaking It for a Risk Map

Original visual: annotated screenshot/diagram of Shark Incidents map.

How to Read a Shark Incident Map

Interactive maps are excellent for discovering patterns. They are also easy to misread.

A cluster of shark incident markers can look like a danger zone even when the map does not contain the information needed to calculate danger. To use the Shark Incidents map responsibly, it helps to understand what each pin represents and what the map leaves out.

A pin represents a recorded event

Each public marker corresponds to a reported, corroborated, verified or otherwise classified incident in the database.

It does not represent:

  • the current position of a shark;
  • the number of sharks at a beach;
  • a prediction of where the next incident will occur;
  • an individual probability of being bitten.

    • Clusters depend on zoom

    At world scale, nearby records are grouped into clusters so thousands of points remain usable. Clicking a cluster zooms into its component records.

    A large cluster can reflect many decades of data. Use the date filter before drawing conclusions about current activity.

    Coordinates have different precision

    Some modern reports identify a named beach. Other records say only “off the coast of” a region. Historical records can be even less precise.

    The site stores coordinate precision with the record.

    When a marker is approximate, the page should say so. Never interpret an approximate point as the exact place where the event occurred.

    Recorded incidents reflect human exposure

    Popular beaches put many more people into the water than remote coastline. Surfing destinations create large amounts of board-sport exposure. Fishing areas create another type of human-shark interaction.

    A map with no denominator cannot tell you the bite rate per swimmer-hour, surfer-hour or visitor.

    Reporting is uneven

    A modern event near a city may be documented by lifeguards, emergency services and multiple news outlets. A similar historical event in a remote location may leave little documentation.

    The absence of markers does not prove the absence of sharks or incidents.

    Filters change the question

    Use filters deliberately.

    If you want to study ordinary recreational bites, filter by classification and verification. If you want to examine all reports, include reported/questionable records and read their status.

    If you are examining species, exclude “unknown” only if you understand that doing so removes a large and potentially non-random part of the record.

    Use the source panel

    Every incident detail page should show the sources behind the marker. New reports can change as more information becomes available.

    The most valuable part of a map is not the dramatic cluster; it is the ability to move from a visual pattern to the evidence behind each record.

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