Critter of the Day: Olive Sea Snakes (Aipysurus laevis)

Sea snakes have a bad rep.  Many people are a little (or a lot!) scared of them and when we list them in our dive brief along with all of the other creatures we expect to see, there is always a little collective gasp and nervous looks.  But we love our olive sea snakes (Aipysurus laevis)and really want you to love them, too.

Let's get the scary bits out of the way.

Yes, they are poisonous and their venom is nasty, even deadly. They have two small fangs at the front of their upper jaw and inject venom through these when they bite. And, yes, I did say at the front. It's common to hear that sea snakes have their fangs way way in the back that you'd really have to work hard to get a body part in there far enough to get bitten, but that's a myth.

But olive sea snakes are very rarely aggressive and you would have to seriously annoy one to be in danger most likely. Mostly, our olive sea snakes are inquisitive and mellow. They will approach us while we are diving to have a little look-see before wandering off on important sea snake business of their own. I would never be afraid or nervous of an olive sea snake here on the Ningaloo Reef and have had them hang out with me - sometimes wrapped around my neck, arm or leg - for an entire dive. Sea snakes should always be given respect but if you just do your thing, they seem happy to just do their thing. Don't want them to be so close to you? Simply rise a meter or two and they tend to wander back closer to the reef, leaving you alone.

See, that's not so scary, is it?!

Sea snakes give birth to live young and usually have 2-5 each time. The juveniles have darker olive patterns along their backs and these dark areas disappear as they mature. Most adults have creamy coloured, large scales though often they will retain a few darker scales, too. Olive sea snakes can grow to about 2m long.

Mating season, which seems to happen several times a year here on the Ningaloo Reef, always provides crazy active sea snake action. The males, usually smaller than the female they are pursuing, coil, nip, rub, dart around and otherwise annoy the female as they twist together tumbling through the water and into the sand. It's hard to keep up with them and they often zip under coral or ledges.

Olive sea snakes eat small fish, prawns, crustaceans and fish eggs. They are reptiles and are related to turtles, lizards & land snakes. They've adapted to their fully aquatic existence by developing a flattened paddle tail and the ability to remain submerged for up to 30 minutes. They do need to surface to breath and it's not unusual to see them resting in the sun on the surface. Their nostrils have valves that they close while underwater so they don't get water up their noses.

We see olive sea snakes on a wide variety of our dive sites here in Exmouth. Blizzard Ridge in Lighthouse Bay has them on virtually every dive with Gulliver's and Labyrinth also having them more often than not. Our Exmouth Gulf sites will see them most dives while out at the Muiron Islands we see them about half of the time.

Olive sea snakes are very cool critters that you shouldn't be afraid of while you are diving. Enjoy them as they hunt for food, sleep under ledges, swim lazily along with you or poke at your buddy's fins! Once you dive with them you'll fall in love, too.