Geoscience Reference
In-Depth Information
Surprise and her calf Sparky”) and reciting useful dolphin facts. The crowd surges into the water, like
acolytes seeking a Jordanian baptism, their expressions beatific.
The dolphins are the crowd pullers—more than six hundred of them live here. But Shark Bay is
also famous for the rest of its wildlife. The bay contains more than 2,600 tiger sharks, not to mention
hammerheads and the occasional great white. The tigers show up in the water as streamlined shadows
up to twelve feet long; often they are skulking beside patches of sea grass in the hope that dinner will
emerge in the form of a blunt-nosed, lumbering grey dugong. Dugongs, or sea cows, are supposedly
the creatures behind the mermaid myths, though I can't see it myself. They are too prosaic, placidly
chewing away at the end of a “food trail”, a line of clear water that they have cut, caterpillar-like,
through the fuzzy green sea grass. They're exceptionally shy and rare, but here, among the largest and
richest sea-grass meadows in the world, are a staggering ten thousand of them—tiger sharks notwith-
standing.
Then there are sea snakes, green turtles and migrating humpback whales. And just a little to the
north, where the tropics begin in earnest, lies Coral Bay—one of the world's top ten dive sites.
Come
and dive the Navy pier! See more than 150 species of fish!
Also sea sponges and corals, brilliant purple
flatworms, snails and lobsters and shrimp. And the vast, harmless whale sharks, the world's biggest
fish. And on land there are wallabies and bettongs and bandicoots, emus and kangaroos and tiny, timid
native mice.
There's everything in this region, from the wonderful to the plain weird. Evolution has been tweak-
ing, adapting and inventing new forms of complex life for hundreds of millions of years, and here in
Western Australia it surely shows.
But this is also a place where you can travel back in time, to see the other side of the evolutionary
equation—the simplest, most primitive creatures of all. They come from the very first moments in the
history of life, just after the dust from the Earth's creation had settled. And when these first fumblings
of life appeared on Earth's surface, their form was exceedingly unprepossessing. Throughout oceans,
ponds and pools, countless microscopic creatures huddled together in a primordial sludge. They coated
the seafloor, and inched their way up shore with the tide; they clustered around steaming hot springs,
and soaked up rays from the faint young sun. Dull green or brown, excreting a gloopy glue that bonded
them together into mats, these creatures were little more than bags of soup. Each occupied a single
cell. Each had barely mastered the rubrics of how to eat, grow and reproduce. They were like indi-
vidual cottage industries in a world that had no interest in collaboration or specialization. They were
as simple as life gets.
Although these primitive slime creatures have now been out-competed in all but the most hostile
environments, a few odd places still exist where you can experience the primeval Earth first-hand.
The acidic hot springs of Yellowstone National Park, for instance, or Antarctica's frigid valleys. And
here, in Western Australia, where countless microscopic, single-celled, supremely ancient creatures
are making their meagre living in one small corner of Shark Bay: a shallow lagoon called Hamelin
Pool. The pool's water doesn't mix much with the rest of the bay, and it's twice as salty as normal.
Since few modern marine animals will tolerate so much salt, this is one of the last refuges of ancient
slime.
T
HE SIGN
pointing to Hamelin Pool is easy to miss, even on the desolate road running south from Mon-
key Mia. On the second pass I finally spot it, turn left, and bump along a sand track with scrubby bush
