Symptoms and Signs of Sea Snake Bite

Medical Author: John P. Cunha, DO, FACOEP
Medically Reviewed on 10/11/2021

Doctor's Notes on Sea Snake Bite

Sea snakes are venomous animals found in tropical and warm waters of the Pacific and Indian Oceans. Sea snakes are usually not aggressive unless provoked or cornered. Bites often occur when fishermen are removing the snakes from fishing nets or if the snake is stepped on while wading in the water. Although they are highly venomous and their venom is very potent and toxic, only some bites result in significant symptoms or envenomation. The venom is injected by fangs but most sea snake species’ fangs are not long enough to penetrate through a wetsuit.

Initially, sea snake bites do not cause pain and there may only be a small pinprick where the bite occurred. There may be anywhere from 1 to 20 “fang” marks. When symptoms do occur they usually begin within 3 hours of the bite and may include

  • muscle pain,
  • inability to move the legs,
  • joint aches,
  • blurred vision,
  • "thick tongue" with difficulty swallowing or speaking,
  • excessive saliva production,
  • vomiting, and
  • droopy eye lids.

If there are no symptoms within 8 hours of being bitten then venom injection is unlikely. 

What Is the Treatment for a Sea Snake Bite?

A bite from a sea snake can be a life-threatening medical emergency. There is no sure way of knowing if the venom (or enough venom) was introduced to the victim by the bite. Even the smallest bite might produce symptoms. 

Victims of a sea snake bite should seek medical care immediately. The death rate for sea snake bites is 3%.

Immediate treatment for a sea snake bite includes:

  • Clean the wound with soap and fresh water if available
  • Apply a pressure bandage to the whole extremity involved in the bite
    • Wrap an elastic bandage (such as an ACE wrap) from the fingers or toes up the limb, tight, but not tight enough to stop circulation to the finger or toe tips
  • Keep the victim calm and do not move the extremity involved if possible
  • Once at a medical facility, anti-venin medication is given intravenously (IV)

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Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.