Coming up next on Jonathan Bird's Blue World, Jonathan travels to an uninhabited island
in Indonesia to find thousands of sea snakes!
Hi, I'm Jonathan Bird and welcome to my world!
Some of the world’s richest coral reefs thrive in Indonesia.
Located in the middle of the so-called coral triangle, the diversity of species and colors
of Indonesian reefs absolutely amazes me every time I get the chance to dive here.
This time however, it’s not the reefs I have come to film, but a remote and uninhabited
island whose waters are reputed to teem with thousands of sea snakes!
The island, known as Manuk, is an active volcano a hundred kilometers from the nearest inhabited
island, smack dab in the middle of the Indonesian archipelago.
Getting there is no easy task.
I have chartered the Seahorse, a traditional Indonesian Pinisi built for divers, for a
special itinerary to reach Manuk Island.
Divemaster Jandri meets me at the marina in Sorong.
It took me 2 full days of flying just to get to Sorong from the United States!
He takes me out to the Seahorse, my home away from home for the next two weeks.
This expedition will take 14 divers 1200 miles across the Banda Sea, from Sorong to Alor,
stopping to dive along the way at many islands, the most important of which of course is Manuk.
I board the Seahorse, and once everyone else has arrived, we pull anchor and head for the
open sea, in search of some serious underwater adventures!
The next morning, we reach our first dive site (so and so island) in Raja Ampat.
I can hardly wait to hit the water and get a look at the spectacular reefs.
Raja Ampat is the most biologically diverse area in Indonesia, and therefore, the world!
As I roll into the water and get my camera, the first thing I see is a wonderfully healthy
shallow hard coral reef!
Nearby are sea fans sheltering tiny fish.
Along the drop off, larger schools of fish hunt, swirling around the reef.
In the deep blue, a school of Spadefish regard me without fear as I swim among them.
Back at the reef, a camouflaged fish lies on the sand between the coral heads.
It’s a crocodilefish, an ambush predator waiting for prey to come close.
Even its eye has camouflage!
Later in the day, I suit up once again for another mind-blowing experience.
This is a dive on a tiny seamount, a coral pillar that would be a small island if only
it were a tad taller.
This underwater tower is the home of the largest school of butterflyfish I have ever seen.
They hover here, in the strong current, apparently feeding on something that the current brings
to them.
They don’t seem to mind my presence at all.
It’s a mesmerizing experience to dive within the school, enveloped on all sides by colorful
fish.
Exhausted by swimming in the current, I relax and drift away from the seamount.
I float gently towards the surface, where I make a short safety stop for decompression.
Finally I head back to the Seahorse, my first day of diving done.
A beautiful day leads to a beautiful sunset, and I can’t wait to see what tomorrow brings!
For five days, the pilot of the Seahorse advances us across Indonesia from island to island,
with wonderful diving every day.
But my mind is focused on one particular spot.
And today, at last we have arrived: Manuk Island.
The island is aptly named: Manuk means “bird” in several Indonesian dialects.
And birds it has!
Manuk is completely uninhabited and there are a few reasons why.
First of all, it’s kind of steep.
But more importantly, it’s an active volcano!
There are steam and sulfur vents all over the island.
Standing downwind, you can smell the distinct odor of brimstone.
But the question is—are there any sea snakes here?
I depart for the first dive with my fingers crossed that I will see tons of sea snakes…
…So, let’s go check it out!
When I get down to the reef, I see a wonderfully healthy ecosystem, with beautiful coral, abundant
fish and crystal clear water.
You couldn’t ask for a nicer place to do a dive.
The walls drop off steeply into deep water.
The reef looks perfectly healthy except for this: an underwater volcanic vent!
Toxic gases and heat are coming out of the sea floor here.
Coral can’t grow too close to this vent.
The water is murky and the rocks are stained yellow.
Whatever I’m swimming in right now is probably not good for me or my camera!
Up in shallow water, volcanic bubbles are percolating out of the sea floor.
Nothing will grow on these rocks either.
The volcanic nature of Manuk Island is everywhere.
Yet, among the volcanic bubbles swims a sea snake!
It is apparently unaffected by the water quality.
It swims casually by flapping its flattened, paddle-like section of tail.
I follow it down onto the reef, mesmerized by its swimming.
Sea snakes are among the most venomous animals on Earth.
They use this venom to hunt, and fortunately, attacks on people are extremely rare.
Soon I start to see other sea snakes, and I realize that more and more have been appearing.
Were they here before and I didn’t see them, or did they come out from someplace?
Clearly, some were sleeping.
This one is taking a nap in plain view on the reef.
I guess they don’t really have to worry about predators.
I watch this one sleep for a little while, and start to wonder if it’s even alive.
So I give it a little tickle.
I wouldn’t do this with a land snake, but sea snakes are very easy-going, almost mellow
and rarely aggressive.
The snake just moves a couple of feet away and goes back to sleep.
Pretty soon I notice that as the snakes are waking up, they are coming over to check me
out.
Are they curious?
They investigate my fins and gear.
They swim closely around me.
I know they are not aggressive, so I just try to stay still and not frighten them.
Look, they are so mellow I can hold one.
Notice how it flicks its tongue.
Like land snakes, this is how a sea snake “smells” but at the same time, the tongue
flicking helps get rid of excess salt from glands in its mouth.
Because sea snakes are reptiles just like land snakes, they have lungs and need to breathe
air just like people.
So a sea snake must head to the surface every once in a while for a breath.
Sea snakes have a huge lung that takes up nearly the entire length of their bodies so
they can hold a big breath that will last a while.
Each time a sea snake surfaces, it usually spends a minute or two resting and breathing,
before gulping in that last big breath and diving back down to the reef.
A breath can last 1-2 hours depending on the species, but most sea snakes breathe more
often than that unless they are sleeping.
They can also absorb a little bit of oxygen from the water directly through their skin,
which helps them extend their dives.
As I ascend from my last dive of the day, I’m really excited about all the sea snakes
I saw!
Wow, that dive was snaketacular!
I’ve seen sea snakes before, but never that many.
The next morning I’m up at sunrise, and heading out to the reef for an early morning
dive.
Early morning is when the sea snakes hunt, and I’m hoping to witness the reef alive
with sea snakes on the prowl!
Underwater, the light levels are still low, and I’m heading out to a deep seamount where
I saw a lot of sea snakes yesterday.
This should be a good place to find some sea snakes hunting.
When a sea snake hunts, it takes advantage of having a small head and a thin body to
go from hole to hole in the reef, poking its head inside.
It hopes to corner a fish or invertebrate that’s hiding in the hole.
Once the hunting starts, more sea snakes start coming in to the reef to join the hunt.
On this seamount more than a hundred feet from the surface, dozens of sea snakes are
gathering to prowl the reef for food.
Sometimes, they appear to work together to make sure nothing escapes.
My time is limited at such a deep site, and all too soon, I must head for shallower water.
There are more sea snakes in the shallows.
Sure, I have seen sea snakes before, but why are there so many here at Manuk Island?
Is it the remoteness of the place, far from people?
Is it a lack of some other predator?
For now, nobody is quite sure.
But there is no doubt about it, Manuk might be named after the Birds but to me it will
always be the island of the snakes.