Sea Snakes of the Great Barrier Reef: Olive, Yellow-Bellied, Banded, Horned, and Tiger Species

The Great Barrier Reef itself has **no native land snakes**—it's a marine ecosystem. However, its waters host a diverse assemblage of **true sea snakes (Hydrophiinae)**—fully marine, venomous elapids adapted to aquatic life.

Species Recorded in GBR Waters

• Olive Sea Snake (Aipysurus laevis): Most common on reefs. Olive-brown, paddle tail, curious, approaches divers. Feeds on fish, crustaceans in crevices.
• Yellow-bellied Sea Snake (Hydrophis platurus): Pelagic; global tropical distribution. Black dorsum, bright yellow ventrum. Drifts on currents; rarely near reefs.
• Elegant / Banded Sea Snake (Hydrophis elegans): Banded pattern; reef-associated. Fish and eel predator.
• Horned Sea Snake (Aipysurus peronii): Distinctive supraocular "horns." Sandy/rubble areas near reefs.
• Tiger Snake (Notechis scutatus): **Not a sea snake**—Australian terrestrial elapid. *Misidentification alert.* The **Turtle-headed Sea Snake (Emydocephalus annulatus)** or **Beaked Sea Snake (Hydrophis schistosus)** may be confused. True tiger snakes are not marine.

Sea Snake Adaptations

• Laterally compressed tail (paddle) for swimming.
• Valvular nostrils, salt glands, cutaneous respiration (up to 30% O₂ uptake).
• Viviparous (live birth at sea); no land needed.
• Potent neurotoxic venom (for fish prey); generally docile unless provoked.

Conservation

Bycatch in trawl fisheries is the main threat. Several species (e.g., Aipysurus foliosquama, A. apraefrontalis) are critically endangered. GBRMPA protects habitat; monitoring continues.

Sea snakes are a fascinating, often overlooked component of reef biodiversity—venomous but rarely a hazard to respectful observers.