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Diver finger injury from Lionfish fin ray

What happened

A diver suffered a finger injury from a Lionfish fin ray. The incident occurred during diving operations, when the diver went to pick up some tooling and the Lionfish came close to the diver.  The diver tried to push the fish away, and in doing so his right thumb was pricked by one of the fin rays of the fish.  The diver was recovered to the bell; on closer inspection there was a slight bleeding and small piece of the fin ray lodged in thumb.  The bell was recovered to surface, where the medic assessed the injury and treated with a wash, dressing and pain killer.

A Lionfish (Fin Ray highlighted)

What were the causes?

Our member noted immediate, underlying, and root causes:

  • Immediate Cause – contact with sharp object (divers right thumb punctured through glove by one of the fish spines);
  • Underlying Causes:
    • Behaviour – Poor decision making / judgement (diver tried to wave / push fish away);
    • Behaviour – Lapse / mistake / omission (divers had been advised to keep clear of hazardous marine life and not attempt to move or engage them in any way);
  • Root Cause – lack of due care in response to known hazard in that region.


Lionfish are harmful to humans. A lionfish sting can be very painful, and though not normally fatal, the sting can cause other potentially serious medical problems for divers. 

Lionfish can be aggressive, even engaging potential threats with a ‘spines forward’ approach; they should be treated with caution at all times. 


  • Review of gloves worn by divers to ensure suitability for protection against venomous fish in that region;
  • Refresher training with dive team on venomous fish hazard and update of risk assessment;
  • Additional controls implemented for remainder of project:
    • Every Dive team briefing included risk of venomous fish;
    • Dive Supervisor monitor video feed and warn of any Lionfish in vicinity;
    • Divers increased buddy watching in water to warn of fish in vicinity.

Members may wish to refer to:

Safety Event

Published: 19 November 2021
Download: IMCA SF 31/21

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