Behavioural risk reduction: timing, location and conditions guidance for water users

Mechanism

Bites cluster in predictable conditions, so guiding behaviour lowers exposure at the moments overlap peaks. Core guidance: avoid low-light periods (dawn, dusk, night); stay out of murky water and don't swim for a day or two after heavy rain or flooding, especially near river mouths, estuaries and canal entrances where bull sharks concentrate; avoid baitfish schools, diving birds and seal colonies; don't swim near anglers or spearfishers; swim in groups at patrolled beaches between the flags; and remove shiny jewellery.

Where it fits

Applies everywhere people enter the ocean and is the only measure that directly addresses both contexts in the parent issue — the post-rainfall estuarine bull-shark setting and open-coast surf beaches. It costs little, scales through signage, apps and lifeguards, and underpins every other measure.

Operating profile

• Zero hardware; delivered through education campaigns, signage and condition-based warnings during elevated-risk periods.
• Probabilistic, not protective: it shifts the odds but cannot make any swim safe.
• Effectiveness depends entirely on awareness and voluntary compliance, and it asks people to forgo swimming at popular times.

Evidence

Shark activity is demonstrably patterned — NSW tracking shows white sharks detected mostly by day and bull sharks peaking seasonally — and the January 2026 east-coast Australian cluster occurred in turbid, post-rainfall water near Sydney Harbour, exactly the conditions this guidance flags. Jurisdictions increasingly fund education and condition-based alerts alongside hardware.